Treatment system, power generator, desulfurization treatment 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. The present invention also relates to a power generation device and a power generation method in anaerobic treatment. The present invention further relates to a desulfurization treatment device and a desulfurization method in anaerobic treatment. [Background technology]

[0002] Generally, biological treatment using various microorganisms is known as a method for treating materials containing organic matter. In particular, biological treatment in an anaerobic environment (hereinafter referred to as "anaerobic treatment") is widely used because of its many advantages, such as not requiring aeration power and hardly producing excess sludge. For example, when the material to be treated is biomass containing a large amount of solids, anaerobic treatment using a digester is known. In addition, various treatment processes and technologies are also combined with anaerobic treatment. For example, one of the technologies that can be used with anaerobic treatment is the generation of electricity using biogas such as methane generated by anaerobic treatment as fuel.

[0003] On the other hand, as a process using microorganisms, a microbial fuel cell is known that generates electricity by utilizing an oxidation-reduction reaction caused by microorganisms. A microbial fuel cell obtains electric energy by utilizing the metabolic ability of microorganisms. More specifically, a microbial fuel cell has a configuration in which electrons generated in the process of oxidative decomposition of substrates such as organic matter 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 of a pair of electrodes is used as an anode and brought into contact with a solution (suspension) containing microorganisms and organic substances capable of growing under anaerobism, and the other electrode is used as a cathode, made of a material having structural voids and brought into 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 anode surface. Patent Document 1 further describes a power generation method in which the power generation device causes an oxidation reaction by microorganisms in the anode using organic substances as electron donors, and a reduction reaction in the cathode using oxygen as an electron acceptor. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] JP 2004-442412 A Summary of the Invention [Problem to be solved by the invention]

[0006] Power generation by a microbial fuel cell as described in Patent Document 1 has low energy conversion efficiency, and improving the power output is a major challenge for practical use. This is presumably because the microorganisms are directly in contact with or supported on the electrodes, and therefore the transfer of substances to the electrodes is inhibited by the microorganisms, and the metabolic rate of the microorganisms is rate-limiting.

[0007] In recent years, in order to reduce the equipment driving power of not only anaerobic treatment but also various treatments of materials to be treated and to make them energy-efficient, there is a demand for technology that can efficiently recover and utilize energy as a technology to be attached to the treatment system. One such technology that has been considered is a technology that applies a microbial fuel cell to a treatment system of materials to simultaneously treat the materials and generate electricity, but as mentioned above, there is a problem in that it is difficult to obtain a sufficient power output.

[0008] Furthermore, as a technology to be associated with the treatment of the materials to be treated, in addition to efficient energy recovery and utilization, there is a demand for technology to efficiently remove harmful substances from the materials to be treated that are generated during treatment such as anaerobic treatment. As such a technology, there is a particular demand for efficient desulfurization treatment to remove hydrogen sulfide that is generated during anaerobic treatment.

[0009] In particular, in anaerobic treatment, it may be necessary to subject the wastewater after anaerobic treatment to anaerobic treatment again or to separately treat the wastewater after anaerobic treatment. In such cases, it is expected that the running costs associated with the treatment of the material to be treated can be reduced and the overall treatment capacity can be improved by utilizing the wastewater generated after anaerobic treatment for power generation or desulfurization.

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

[0011] As a result of extensive research into the above-mentioned problems, the inventors discovered that by carrying out a reaction using, as an electron donor, reducing substances in the filtrate obtained by solid-liquid separation of the wastewater after anaerobic treatment, it is possible to efficiently recover and utilize energy through power generation and to perform desulfurization in wastewater treatment, and thus completed the present invention. That is, the present invention relates to the following treatment system, power generation device, desulfurization treatment device, power generation method, and desulfurization method.

[0012] The treatment system of the present invention, which is intended to solve the above problems, is a treatment system equipped with a digestion facility that performs anaerobic treatment on the material to be treated, and is characterized in that it generates electricity by a reaction in which reducing substances in the filtrate obtained by solid-liquid separation of the wastewater after anaerobic treatment act as electron donors.

[0013] The treatment system of the present invention generates electricity by directly using the reducing substances contained in the filtrate obtained by solid-liquid separation of the effluent after anaerobic treatment as electron donors, and thus generates electricity efficiently because there is no inhibition of mass transfer by microorganisms. In addition, the equipment can be made smaller than that required for power generation using a microbial fuel cell. Furthermore, electricity can be generated by utilizing the effluent generated after anaerobic treatment, which reduces the running costs associated with anaerobic treatment and improves the treatment capacity of the entire treatment system.

[0014] Another aspect of the treatment system of the present invention for solving the above problems is a treatment system equipped with a digestion facility that performs anaerobic treatment on the material to be treated, and is characterized in that desulfurization is performed by a reaction in which reducing substances in the filtrate obtained by solid-liquid separation of the effluent after anaerobic treatment act as electron donors.

[0015] The treatment system of the present invention performs desulfurization treatment by directly using a reducing substance contained in the filtrate obtained by solid-liquid separation of the effluent after anaerobic treatment as an electron donor, thereby converting hydrogen sulfide, which is a reducing substance, into sulfur, and making it possible to efficiently remove hydrogen sulfide from the material to be treated. In addition, the desulfurization treatment can be performed on the effluent generated after anaerobic treatment, making it possible to reduce the running costs associated with anaerobic treatment and improve the treatment capacity of the entire treatment system.

[0016] One embodiment of the treatment system of the present invention is characterized in that it includes a power generation section that brings the filtrate into contact with electrodes to generate power. According to this feature, by installing electrodes so as to be in contact with the filtrate, it becomes possible to generate electricity during a series of processes in the treatment of the object to be treated. This makes it possible to generate electricity efficiently without enlarging the size of the equipment. In addition, at this time, an electrode reaction proceeds in which hydrogen sulfide contained in the filtrate serves as an electron donor, converting it to sulfur. This makes it possible to perform efficient desulfurization without providing a separate facility for desulfurization.

[0017] Moreover, one embodiment of the treatment system of the present invention is characterized in that an ion exchanger is disposed between the electrodes. According to this feature, it is possible to increase the efficiency of electron transfer between the pair of electrodes, and therefore it is possible to further improve the power generation efficiency and the desulfurization treatment efficiency.

[0018] Furthermore, one embodiment of the treatment system of the present invention is characterized in that it is provided with a contact efficiency improving means for improving the contact efficiency between the electrode surface of the power generation unit and the electrode reaction components including reducing substances in the filtrate. According to this feature, it is possible to improve the contact efficiency between the electrode surface of the power generation unit and the electrode reaction components, thereby suppressing a decrease in the efficiency of the electrode reaction and improving the efficiency of power generation and desulfurization treatment.

[0019] In one embodiment of the treatment system of the present invention, the contact efficiency improving means is characterized by comprising a transfer rate control means for increasing the transfer rate of the electrode reaction component relative to the electrode surface. According to this feature, it is possible to rapidly supply the electrode reaction components to the electrode surface, thereby improving the contact efficiency between the electrode surface and the electrode reaction components, thereby suppressing a decrease in the efficiency of the electrode reaction and improving the efficiency of power generation and desulfurization treatment.

[0020] In one embodiment of the treatment system of the present invention, the transfer rate control means is characterized in that it comprises a temperature control means for a reaction in which a reducing substance in the filtrate serves as an electron donor. According to this feature, it is possible to control the temperature so as to improve the mass transfer rate and the reaction efficiency in the reaction in which the reducing substance serves as the electron donor, thereby making it possible to increase the power generation efficiency and the desulfurization efficiency.

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

[0022] Moreover, one embodiment of the treatment system of the present invention is characterized in that, as the concentration control means, a pH control means is provided for dissolving reducing substances in the filtrate in the filtrate. This feature allows the filtrate to retain more reducing substances, the solubility of which changes depending on the pH of the solution, and increases the amount of reducing substances available for reaction as electron donors, which makes it possible to improve power generation efficiency and desulfurization efficiency.

[0023] In one embodiment of the treatment system of the present invention, the contact efficiency improving means is characterized by comprising a cleaning means for cleaning deposits accumulated on the electrode surface. According to this feature, it is possible to remove deposits on the electrode surface, thereby improving the contact efficiency between the electrode surface and the electrode reaction components, suppressing a decrease in the efficiency of the electrode reaction, and improving the efficiency of power generation and desulfurization treatment.

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

[0025] In addition, in one embodiment of the treatment system of the present invention, the combustion device is characterized in that it incinerates the solid matter obtained by solid-liquid separation of the effluent after anaerobic treatment and / or combusts the gas produced by anaerobic treatment. This feature allows the combustion target to be easily obtained, and allows the use of existing combustion equipment for solid matter processing and gas utilization, eliminating the need to install a new combustion equipment for the treatment system of the present invention, and making it possible to significantly reduce initial costs.

[0026] Moreover, one embodiment of the treatment system of the present invention is characterized in that it comprises a degassing means for removing gas contained in the electrodes of the power generation section. According to this feature, by providing a degassing means for removing gas contained in the electrode, the problem of a decrease in the specific surface area inside the electrode can be solved, thereby suppressing a decrease in the efficiency of the electrode reaction and enabling the efficiency of power generation and desulfurization treatment to be improved.

[0027] In addition, the power generation device of the present invention for solving the above problems is a power generation device that is installed in a treatment system that anaerobically treats the material to be treated, and has a feature in that it generates electricity by using, as an electron donor, reducing substances in the filtrate obtained by solid-liquid separation of the discharged material after anaerobic treatment. The power generation device of the present invention generates power by directly using the reducing substances contained in the filtrate obtained by solid-liquid separation of the effluent after anaerobic treatment as electron donors, and thus generates power efficiently because there is no inhibition of mass transfer by microorganisms. In addition, the equipment can be made smaller than that used for power generation by a microbial fuel cell. Furthermore, power can be generated by utilizing the effluent generated after anaerobic treatment, which reduces the running costs associated with anaerobic treatment and improves the processing capacity of the entire treatment system. Furthermore, by applying the power generation device of the present invention to an existing treatment system, it becomes possible to upgrade the treatment system to one that can generate power without requiring a large-scale upgrade of the entire treatment system.

[0028] In addition, the desulfurization treatment device of the present invention for solving the above problems is a desulfurization treatment device that is installed in a treatment system that anaerobically treats the material to be treated, and has a feature in that reducing substances in the filtrate obtained by solid-liquid separation of the discharged material after anaerobic treatment are subjected to desulfurization treatment as electron donors. The desulfurization treatment device of the present invention performs desulfurization treatment by directly using a reducing substance contained in the material to be treated as an electron donor, thereby enabling efficient desulfurization without discharging hydrogen sulfide to the outside of the system. In addition, the desulfurization treatment can be performed on the discharged material generated after anaerobic treatment, which makes it possible to reduce the running costs associated with anaerobic treatment and improve the treatment capacity of the entire treatment system. Furthermore, by applying the desulfurization treatment device of the present invention to an existing treatment system, it is possible to upgrade the treatment system to one that can perform desulfurization without having to perform a large-scale upgrade to the entire treatment system.

[0029] In addition, the power generation method of the present invention for solving the above problems is a power generation method in wastewater treatment in which the material to be treated is anaerobically treated, and is characterized by including a step of generating power by using, as an electron donor, reducing substances in a filtrate obtained by solid-liquid separation of the effluent after anaerobic treatment. In the power generation method of the present invention, the reducing substance contained in the filtrate obtained by solid-liquid separation of the effluent after anaerobic treatment is directly used as an electron donor to generate power, and since there is no inhibition of mass transfer by microorganisms, it is possible to generate power efficiently. In addition, it is possible to reduce the size of the equipment compared to power generation using a microbial fuel cell. Furthermore, it is possible to generate power by utilizing the effluent generated after anaerobic treatment, which makes it possible to reduce the running costs related to anaerobic treatment and improve the processing capacity of the entire treatment system.

[0030] Furthermore, the desulfurization method of the present invention for solving the above-mentioned problems is a desulfurization method in wastewater treatment in which the material to be treated is anaerobically treated, and is characterized by comprising a step of subjecting reducing substances in a filtrate obtained by solid-liquid separation of the effluent after anaerobic treatment to desulfurization treatment as electron donors. The desulfurization method of the present invention performs desulfurization treatment by directly using a reducing substance contained in the material to be treated as an electron donor, thereby enabling efficient desulfurization without discharging hydrogen sulfide to the outside of the system. In addition, the desulfurization treatment can be performed on the discharged material generated after anaerobic treatment, which makes it possible to reduce the running costs associated with anaerobic treatment and improve the treatment capacity of the entire treatment system. Effect of the Invention

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

[0032] [Figure 1] FIG. 1 is a schematic explanatory diagram of a processing system according to a first embodiment of the present invention. [Diagram 2] FIG. 1 is a schematic explanatory diagram of a processing system according to a second embodiment of the present invention. [Diagram 3] FIG. 11 is a schematic explanatory diagram showing another aspect of the processing system according to the second embodiment of the present invention. [Figure 4] FIG. 11 is a schematic explanatory diagram of a processing system according to a third embodiment of the present invention. [Diagram 5] FIG. 11 is a schematic explanatory diagram showing a contact efficiency improving means (movement speed control means) in the treatment system according to the third embodiment of the present invention. [Figure 6] FIG. 13 is a schematic explanatory diagram showing another mode of the moving speed control means in the processing system according to the third embodiment of the present invention. [Figure 7] FIG. 13 is a schematic explanatory diagram showing another mode of the moving speed control means in the processing system according to the third embodiment of the present invention. [Figure 8] FIG. 13 is a schematic explanatory diagram showing another mode of the moving speed control means in the processing system according to the third embodiment of the present invention. [Figure 9] FIG. 13 is a schematic explanatory diagram showing another mode of the moving speed control means in the processing system according to the third embodiment of the present invention. [Figure 10] FIG. 13 is a schematic explanatory diagram showing another mode of the moving speed control means in the processing system according to the third embodiment of the present invention. [Figure 11] FIG. 11 is a schematic explanatory diagram showing another aspect of the contact efficiency improving means (concentration control means) in the treatment system according to the third embodiment of the present invention. [Figure 12]FIG. 11 is a schematic explanatory diagram showing another mode of the concentration control means in the treatment system according to the third embodiment of the present invention. [Figure 13] FIG. 11 is a schematic explanatory diagram showing another mode of the concentration control means in the treatment system according to the third embodiment of the present invention. [Figure 14] FIG. 11 is a schematic explanatory diagram showing another mode of the concentration control means in the treatment system according to the third embodiment of the present invention. [Figure 15] FIG. 11 is a schematic explanatory diagram showing a contact efficiency improving means (cleaning means) in the treatment system according to the fourth embodiment of the present invention. [Figure 16] FIG. 11 is a schematic explanatory view showing another aspect of the cleaning means in the treatment system according to the fourth embodiment of the present invention. [Figure 17] FIG. 11 is a schematic explanatory view showing another aspect of the cleaning means in the treatment system according to the fourth embodiment of the present invention. [Figure 18] FIG. 11 is a schematic explanatory view showing another aspect of the cleaning means in the treatment system according to the fourth embodiment of the present invention. [Figure 19] FIG. 11 is a schematic explanatory view showing another aspect of the cleaning means in the treatment system according to the fourth embodiment of the present invention. [Figure 20] FIG. 13 is a schematic explanatory diagram of a processing system according to a fifth embodiment of the present invention. [Figure 21] FIG. 13 is a schematic explanatory diagram showing another aspect of the processing system in the fifth embodiment of the present invention. [Figure 22] FIG. 13 is a schematic explanatory diagram showing a degassing means in a treatment system according to a sixth embodiment of the present invention. [Figure 23] FIG. 13 is a schematic explanatory diagram showing another mode of the degassing means in the treatment system according to the sixth embodiment of the present invention. [Figure 24] FIG. 13 is a schematic explanatory diagram showing another mode of the degassing means in the treatment system according to the sixth embodiment of the present invention. [Diagram 25] FIG. 13 is a schematic explanatory diagram showing an insulation mechanism in a treatment system according to a seventh embodiment of the present invention. [Figure 26] FIG. 13 is a schematic explanatory view showing another example of an insulating mechanism in the treatment system according to the seventh embodiment of the present invention. [Figure 27] FIG. 13 is a schematic explanatory view showing another example of an insulating mechanism in the treatment system according to the seventh embodiment of the present invention. [Figure 28] FIG. 13 is a schematic explanatory diagram of a processing system according to an eighth embodiment of the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0033] Hereinafter, embodiments of the treatment system, power generation apparatus, desulfurization treatment 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 according to the present invention are replaced with the description of the operation of the treatment system, power generation apparatus, and desulfurization treatment apparatus according to the present invention. The treatment system, power generation apparatus, desulfurization treatment apparatus, power generation method, and desulfurization method described in the embodiments are merely examples used to explain the treatment system, power generation apparatus, desulfurization treatment apparatus, power generation method, and desulfurization method of the present invention, and are not limited thereto.

[0034] In the treatment system of the present invention, the treated object is not particularly limited. It is preferable that the treated object generates a reducing substance as the treatment progresses in the treatment system. Specific examples of the treated object include, for example, biomass such as food waste and food waste, and wood discharged from homes and various factories, as well as excess sludge after treating industrial wastewater and domestic wastewater such as sewage discharged from various factories. In the following embodiment, the treated object will be mainly described as a material that generates a reducing substance through treatment, but is not limited thereto.

[0035] In the present invention, the reducing substance is not particularly limited as long as it functions as an electron donor. Whether a certain substance functions as an electron donor is determined relatively depending on the 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 can be one that is more likely to release electrons than the electron acceptor, that is, one that has a lower redox potential than the electron acceptor. For example, when oxygen is used as the electron acceptor, the reducing substance in the present invention can be one that has a lower redox potential than oxygen, and examples of such reducing substances include hydrogen sulfide, hydrogen, and ammonia.

[0036] [First embodiment] (Processing System) FIG. 1 is a schematic explanatory diagram showing the structure of a processing system according to a first embodiment of the present invention. 1, the treatment system 1A in this embodiment includes a treatment tank 2, a solid-liquid separation section 3, and a power generation section 4. The treatment system 1A also includes an inlet pipe L1 for introducing the material S to be treated into the treatment tank 2, a connection pipe L2 for connecting the treatment tank 2 and the solid-liquid separation section 3, an inlet pipe L3 for introducing the filtrate F separated in the solid-liquid separation section 3 into the power generation section 4, a discharge pipe L4 for discharging the solid matter separated in the solid-liquid separation section 3 to the outside of the system, and a discharge pipe L5 for discharging the treated water W2 from the power generation section 4 to the outside of the system.

[0037] In the treatment system 1A shown in Fig. 1, the material to be treated S is subjected to anaerobic treatment in a treatment tank 2, and the discharged material after anaerobic treatment (treated liquid W1) is separated into filtrate F and solid matter in a solid-liquid separation section 3, and the filtrate F is introduced into a power generation section 4. This makes it possible to utilize the discharged material after anaerobic treatment of the material to be treated S, and to perform more efficient energy recovery and utilization or desulfurization treatment. Each component of the processing system 1A will be described below.

[0038] (Treatment tank) The treatment tank 2 is a tank for subjecting the material S to anaerobic treatment. The treatment carried out in the treatment tank 2 is not particularly limited as long as it is an anaerobic treatment suitable for the treatment target contained in the material to be treated S and contains reducing substances in the discharged product after treatment (treated liquid W1). For example, it may be methane fermentation using acid-producing bacteria and methanogenic bacteria, denitrification treatment in which nitrate and nitrite are reduced by denitrifying bacteria, or sulfate reduction treatment in which sulfate is reduced by sulfate-reducing bacteria. In terms of the treatment cost and the usefulness of the generated gas, methane fermentation that produces methane is particularly preferable as the anaerobic treatment performed in the treatment tank 2 in this embodiment. Therefore, the treatment tank 2 preferably has a structure that functions as a digestion facility that digests the material to be treated S. More specifically, the treatment tank 2 preferably has a known structure as a digestion tank, and the specific structure of the digestion tank is not particularly limited.

[0039] When anaerobic treatment, particularly methane fermentation, is carried out in the treatment tank 2, hydrogen sulfide, hydrogen, ammonia, and the like are produced in addition to methane in the discharge (treated liquid W1) after treatment of the material to be treated S. These products correspond to the reducing substances in the present invention.

[0040] The material S treated in the treatment tank 2 becomes a discharge (treated liquid W1) containing reducing substances, and is introduced into the solid-liquid separation section 3 via a connecting pipe L2.

[0041] (Solid-liquid separation section) The solid-liquid separation section 3 separates the treatment liquid W1 introduced from the treatment tank 2 into solid matter and filtrate F. Here, the treated liquid W1 separated in the solid-liquid separation section 3 is a discharged product after anaerobically treating in the treatment tank 2, and is a solid-liquid mixture (sludge) containing muddy matter such as excess sludge. The treated liquid W1 also contains reducing substances produced by methane fermentation. Therefore, by subjecting the treated liquid W1 to solid-liquid separation in the solid-liquid separation section 3 and recovering the filtrate F containing the reducing substance, it is possible to proceed with the reaction in which the reducing substance serves as an electron donor.

[0042] The solid-liquid separation section 3 is not particularly limited as long as it can separate the solid matter contained in the treatment liquid W1 from the filtrate F. For example, it may be a sedimentation separation type such as a coagulation sedimentation tank or a sedimentation tank, a centrifugal separation type equipped with a centrifuge, or a pressurized filtration device such as a belt press dehydrator or a screw press dehydrator.

[0043] The filtrate F separated in the solid-liquid separation section 3 is introduced into the power generation section 4 via the inlet pipe L3 as treated water W2 containing reducing substances. Meanwhile, the solid matter separated in the solid-liquid separation section 3 is discharged outside the system via the discharge pipe L4. At this time, a treatment facility for treating the solid matter may be provided downstream of the discharge pipe L4.

[0044] (Power Generation Section (Power Generation Equipment / Desulfurization Equipment)) The power generation unit 4 generates power by using the reducing substances in the filtrate F as electron donors. Moreover, the power generation unit 4 in this embodiment 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 section 4 of this embodiment will be described below from the viewpoint of power generation. The desulfurization process by the power generation section 4 of this embodiment will be described in detail later.

[0045] As shown in FIG. 1, the power generation unit 4 of this embodiment is provided at the rear of the solid-liquid separation unit 3, and includes a first cell 41a and a second cell 41b, an ion exchanger 45 provided to separate the cells 41a and 41b, and electrodes 43a and 43b arranged in the 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 through 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 so as to store or supply an electron acceptor, and the electrode 43b arranged in the second cell 41b functions as a cathode. In addition, the electrodes 43a and 43b are connected to an external circuit by a conductor (not shown). This makes it possible to recover and utilize electrical energy generated in the power generation unit 4 by the action of the reducing substance as an electron donor.

[0046] The first cell 41a may be any material or shape as long as it is provided with an electrode 43a and is formed so that the filtrate F comes into contact with the electrode 43a. For example, as shown in FIG. 1, the first cell 41a may have a space capable of temporarily storing the filtrate F introduced from the inlet 42a via the inlet piping L3, and may be provided with a discharge piping L5 for discharging the treated water W2 from the discharge piping L5 after contacting the electrode 43a. As a result, the reducing substances in the filtrate F are quickly discharged through the discharge piping L5 after donating electrons to the electrode 43a as electron donors. The positional relationship between the inlet 42a and the discharge piping 42b is not particularly limited. For example, as shown in FIG. 1, the inlet 42a may be provided on the side of the first cell 41a and the discharge piping 42b may be provided on the bottom surface of the first cell 41a, or the inlet 42a and the discharge piping 42b may be provided on the side of the first cell 41a and the discharge piping 42b may be provided at a position vertically higher than the inlet 42a.

[0047] In addition, the inlet pipe L3 and / or the outlet pipe L5 may be provided with a flow rate adjustment mechanism such as a valve, which makes it possible to adjust the amount and flow rate of the filtrate F brought into contact with the electrode 43a and control the mass transfer rate to the electrode 43a.

[0048] The treated water W2 discharged through the discharge pipe L5 can be discharged as is if it meets the water quality requirements for discharge into a river or the like. In addition, a treatment facility for further treating the treated water W2 may be provided downstream of the discharge pipe L5, and the treated water W2 may be discharged outside the system after being treated. Such treatment facility is not particularly limited as long as it can treat the treated water W2 to a water quality suitable for discharge outside the system or into a river. Examples include an aeration tank and a pH adjustment tank.

[0049] The second cell 41b may be any cell as long as it is provided with an electrode 43b and is formed so as to store or supply an electron acceptor for the reducing substances in the filtrate F, and there is no particular restriction on the material or shape of the second cell 41b.

[0050] Here, the electron acceptor may be in the form of either gas or liquid. The liquid may be a solution in which a solid drug is dissolved, or a solution in which a gas is mixed (dissolved). Specific examples of the electron acceptor in this embodiment include gases such as oxygen and gases containing oxygen. Incidentally, examples of gases containing oxygen include those containing oxygen as a mixture such as air, and those containing oxygen as an element constituting a compound such as carbon dioxide. When a gas is used as the electron acceptor, there are advantages in that the treatment of the gas discharged 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. In addition, other examples of the electron acceptor in this embodiment include, for example, a liquid solution containing dissolved oxygen, an aqueous solution of an oxidizing agent such as an aqueous solution of potassium ferricyanide, etc. When a liquid is used as the electron acceptor, it is advantageous in that the compound (oxidizing agent) that is highly effective as an electron acceptor can be easily handled, and therefore the power generation efficiency can be further improved. From the viewpoint of improving the 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 FIG. 1, in order to supply a gaseous electron acceptor (oxygen, air, etc.) to the electrode 43b, an electron acceptor supply port 44a for supplying a gas and an electron acceptor discharge port 44b for discharging the gas after the reaction may be provided in the second cell 41b. Another example of the second cell 41b is to provide a space capable of storing a liquid in the second cell 41b, and provide the electron acceptor supply port 44a and the electron acceptor discharge port 44b that can supply a solution of the electron acceptor and discharge the solution after the reaction, respectively. This allows the electron acceptor to receive electrons from the electrode 43a via the electrode 43b, and a current flows between the electrodes 43a and 43b to generate electricity. In addition, the electron acceptor after the reaction is quickly discharged to the outside of the power generation unit 4 via the electron acceptor discharge port 44b. A flow rate adjusting mechanism such as a valve may be provided at the electron acceptor supply port 44a and / or the electron acceptor discharge port 44b to adjust the concentration of the electron acceptor in the second cell 41b. Furthermore, a control mechanism may be provided to control the flow rate adjusting mechanism so that the electron acceptor concentration is maintained according to the amount of electrons generated by the reaction at the electrode 43a. This makes it possible to suppress a decrease in the reaction efficiency related to the electron transfer between the electrodes 43a and 43b and suppress a decrease in the power generation efficiency.

[0052] 1, one each of the electron acceptor supply port 44a and the electron acceptor discharge port 44b is shown, but the present invention is not limited thereto. For example, a plurality of electron acceptor supply ports 44a and electron acceptor discharge ports 44b may be provided. In particular, when a gas containing oxygen is used as the electron acceptor, water is generated by a reaction at the electrode 43b, as described below. Therefore, when a plurality of electron acceptor discharge ports 44b are provided, for example, one for discharging gas and one for discharging liquid may be provided separately.

[0053] The ion exchanger 45 may have a known structure that allows ions to pass through, and is not particularly limited. In particular, it may be a cation exchange membrane that allows hydrogen ions generated at the electrode 43a (anode side) to pass through. This allows hydrogen ions to move from the electrode 43a (anode side) to the electrode 43b (cathode side), thereby increasing the reaction efficiency of the electron acceptor at the electrode 43b and improving the power generation efficiency. In addition, it is more preferable that the ion exchanger 45 has low oxygen permeability. This makes it possible to suppress the electron acceptor (oxygen) supplied to the electrode 43b (cathode side) from moving to the electrode 43a side, and to suppress the reaction efficiency of the electron donor at the electrode 43a from decreasing due to oxygen. 1, the ion exchanger 45 is shown as being provided separately from the electrodes 43a and 43b, but is not limited thereto. For example, a material having ion exchange ability may be integrated with the electrodes 43a and / or 43b. This allows the power generation unit 4 to be made smaller as a whole, and also shortens the time required for maintenance work.

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

[0055] The electrode 43a may be any material that functions as an anode, and there are no particular limitations on the material and shape. The material and shape of the electrode 43a may be appropriately selected in consideration of the costs involved in material procurement and processing, and the reaction efficiency of the reducing substance in the electrode 43a. Examples of the material of the electrode 43a include carbon and metals (stainless steel, platinum, copper, etc.) that are widely used as electrode materials in the field of electrochemistry. Examples of the shape of the electrode 43a include a flat plate, a rod, a mesh, etc.

[0056] In this embodiment, the electrode 43a does not have microorganisms in contact with or supported on the electrode surface. Therefore, mass transfer of the reducing substance is not inhibited by the microorganisms, and the reaction efficiency as an electron donor (the mass transfer rate of the reducing substance to the electrode 43a) can be improved, and the power generation efficiency can be improved. In addition, the electrode 43a in this embodiment does not collect electrons generated by the metabolism of the microorganism, but collects electrons directly from the reducing substance. Therefore, the metabolism of the microorganism is not rate-limiting, and the reaction efficiency as an electron donor (electron collection speed at the electrode 43a) is improved, thereby improving the power generation efficiency.

[0057] Furthermore, the electrode 43a in this embodiment does not need to be processed so that the structure of the electrode 43a is suitable for holding microorganisms, and the cost of producing the electrode 43a can be reduced. In addition, in consideration of the amount of microorganisms held by the electrode 43a and the reaction efficiency of the microorganisms, there is no need to make the electrode 43a large, and therefore the equipment related to the treatment system can be made small.

[0058] The electrode 43b is a counter electrode of the electrode 43a, and is an electrode that transfers electrons to the electron acceptor, and functions as a so-called cathode. The electrode 43b in this embodiment is disposed in the second cell 41b.

[0059] The electrode 43b may be any material that functions as a cathode, and there are no particular limitations on the material and shape. The material and shape of the electrode 43b may be appropriately selected in consideration of the costs involved in material procurement and processing, and the reaction efficiency of the electron acceptor in the electrode 43b. Examples of the material of 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 the shape of the electrode 43b include a flat plate, a rod, a mesh, etc.

[0060] When the electron acceptor supplied to the second cell 41b is a gas (air), one side of the electrode 43b contacts the gas, while the other side contacts the filtrate F. For this reason, the electrode 43b is preferably in a form suitable for use as a so-called air cathode. Examples of a form suitable for use as an air cathode include a form having both gas permeability and water impermeability. By making the electrode 43b in a form having gas permeability, it is possible to effectively react the gas, which is the electron acceptor, at the electrode 43b. In addition, by making the electrode 43b water impermeable, it is possible to prevent the filtrate F in the first cell 41a from passing through the electrode 43b and flowing into the second cell 41b. Specific examples of such an electrode 43b include one made of carbon fiber, and one in which a surface treatment such as coating a material having gas permeability and water impermeability or lamination of a film is performed on the surface of a metal mesh. In this case, impermeable refers to not allowing water to pass through. For example, making electrode 43b waterproof, water-repellent, hydrophobic, or water-stopping is also included in being impermeable.

[0061] The treatment system 1A in this embodiment uses a reducing substance in the filtrate F as an electron donor to generate electricity or perform desulfurization treatment by electrochemical reaction (electrode reaction). In general, when performing an electrochemical reaction, the electrons move to a location other than the location where the electrochemical reaction actually occurs (the power generation unit 4), which causes a problem of reduced efficiency of the electrochemical reaction. Therefore, in the treatment system 1A in this embodiment, it is preferable to insulate the location other than the location where the electrochemical reaction occurs (the power generation unit 4). Specific examples of the insulation treatment include, for example, placing the treatment tank 2 and the solid-liquid separation unit 3 on top of an insulator, constructing the outer wall or inner wall of the treatment tank 2 and the solid-liquid separation unit 3 from an insulator, or coating the outer wall or inner wall of the treatment tank 2 and the solid-liquid separation unit 3 with an insulating material. In addition, examples of the insulation treatment of each of the pipes L1 to L5 include making each pipe from an insulator, coating each pipe with an insulating material, and the like.

[0062] In the treatment system 1A in the present embodiment described above, power generation or desulfurization can be performed by a reaction in which the reducing substances in the filtrate F serve as electron donors. The power generation and desulfurization process in the treatment system 1A will be described in detail below.

[0063] (Power generation and desulfurization in treatment systems) The reactions and steps involved in power generation and desulfurization in the treatment system 1A of the first embodiment of the present invention will be described with reference to Fig. 1. The reactions and steps involved in power generation in the treatment system of this embodiment will be described as using, as the electron donor, a reducing substance contained in the filtrate F obtained by solid-liquid separation of the discharge (treated liquid W1) after anaerobic treatment of the material to be treated S, and using air (oxygen) as the electron acceptor. In particular, the reaction and steps using hydrogen sulfide as the electron donor correspond to the reactions and steps involved in the desulfurization in the treatment system of this embodiment. The explanation of the reactions and steps based on Fig. 1 shows an example of power generation and desulfurization in this embodiment, and is not limited thereto. The following explanation describes the reactions and steps related to the treatment tank 2 to the power generation section 4, and the reactions and steps related to other configurations (such as the inlet pipes L1 and L3, the connection pipe L2, the discharge pipes L4 and L5, and the treatment equipment provided after the discharge pipes L4 and L5) are omitted. Furthermore, the notation of reactions R1 to R4 and steps S1 to S4 is numbered for the purpose of explanation, and does not specify the order of the reactions and steps.

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

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

[0066] The filtrate F containing the reducing substance is introduced into the first cell 41a of the power generation unit 4 (step S3). Here, the reducing substance (hydrogen, hydrogen sulfide, ammonia, etc.) comes into contact with the electrode 43a, whereby the reducing substance functions as an electron donor and donates electrons to the electrode 43a. In this case, taking hydrogen sulfide as an example of a reducing substance that functions as an electron donor, the reaction (reaction R1) at the electrode 43a is represented by the following reaction formula (formula 1).

number

[0067] In addition, some of the hydrogen sulfide reacts as hydrogen sulfide ions. The reaction at this time is shown in the following reaction formula (Formula 2).

number

[0068] As shown in formulas 1 and 2, in reaction R1, hydrogen sulfide contained in the filtrate F donates electrons to the electrode 43a, and hydrogen sulfide itself is oxidized to become harmless and odorless. Therefore, the treatment system of this embodiment is capable of desulfurization and deodorization as well as power generation. Note that reducing substances (ammonia, etc.), which are harmful substances and odorous substances other than hydrogen sulfide, also function as electron donors in the same way, and as the reaction progresses, they can be rendered harmless and odorless.

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

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

number

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

[0072] As described above, by using the treatment system 1A of this embodiment, it is possible to utilize the discharged material after anaerobic treatment of the material to be treated, and to perform efficient energy recovery and utilization by power generation and desulfurization treatment in the anaerobic treatment. In particular, by enabling an electrode reaction using a reducing substance contained in the filtrate obtained by solid-liquid separation of the discharged material after anaerobic treatment, it is possible to improve the efficiency of power generation and desulfurization treatment without the inhibition of mass transfer by microorganisms or the rate-limiting step based on the metabolic rate of microorganisms. In addition, the equipment can be made smaller than that for power generation by a microbial fuel cell. Furthermore, it is possible to perform efficient desulfurization treatment without separately installing equipment for desulfurization treatment.

[0073] In conventional power generation using microbial fuel cells, it is known that 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 the present embodiment can perform treatment of the material to be treated (anaerobic treatment) and power generation separately. Therefore, in the treatment system and power generation method of the present embodiment, there is no trade-off between the treatment efficiency of the material to be treated and the power generation efficiency, making it possible to generate power efficiently.

[0074] 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 large-scale renewal of the entire treatment system. In addition, it is possible to provide a power generation method and a desulfurization method using this treatment system.

[0075] [Second embodiment] FIG. 2 is a schematic explanatory diagram showing a processing system according to a second embodiment of the present invention. The treatment system 1B according to the second embodiment is configured such that a storage section 46 for the treated water W2 is provided in the power generation section 4 of the treatment system 1A according to the first embodiment, and the treated water W2 is circulated between the first cell 41a and the storage section 46. Note that a description of the same configuration as that of the first embodiment will be omitted.

[0076] As shown in Figure 2, the power generation section 4 of the treatment system 1B in this embodiment is similar to the power generation section 4 in the first embodiment, but includes a storage section 46 for storing the treated water W2 and a circulation flow path 47 connecting the cathode side (first cell 41a) of the power generation section 4 to the storage section 46.

[0077] The storage unit 46 is not particularly limited as long as it can store the treated water W2, and may be, for example, a sealable tank. The treated water W2 can be repeatedly subjected to the electrode reaction by storing the treated water W2 in the storage section 46 via the circulation flow path 47 and returning the treated water W2 to the first cell 41a again. This allows the reducing substances contained in the treated water W2 to be efficiently consumed in the electrode reaction, and in particular, makes it possible to increase the efficiency of the desulfurization treatment.

[0078] Furthermore, the storage unit 46 in this embodiment may have a function other than repeatedly subjecting the treated water W2 to the electrode reaction. FIG. 3 is a schematic explanatory diagram showing another aspect of the processing system 1B of this embodiment. As shown in Figure 3, another embodiment of the treatment system 1B includes a connection pipe L6 that connects the treatment tank 2 to the storage unit 46 shown in Figure 2 in order to introduce gas G (biogas) generated in the treatment tank 2 to the storage unit 46, and a discharge pipe L7 that discharges the gas G from the storage unit 46. By providing the connection pipe L6 and bringing the biogas generated in the treatment tank 2 into contact with the treated water W2, it is possible to perform a desulfurization process that reduces the hydrogen sulfide contained in the biogas. Furthermore, by providing the discharge pipe L7, it is possible to discharge or recover the biogas after the desulfurization process. This allows the storage unit 46 to have functions related to the desulfurization process and recovery of the gas G (biogas) generated in the treatment tank 2. In addition, it is preferable to provide equipment related to the utilization of the biogas, such as a gas storage facility, downstream of the discharge pipe L7 (not shown). This makes it easy to use the recovered biogas as an energy source after the desulfurization process.

[0079] As described above, by using the treatment system 1B of this embodiment, the treated water on the cathode side after the electrode reaction in the power generation unit can be repeatedly introduced into the power generation unit, thereby increasing the reaction efficiency in which the reducing substance serves as the electron donor, and making it possible to carry out a particularly efficient desulfurization treatment. Moreover, the treatment system 1B of this embodiment can effectively perform desulfurization and recovery of the biogas generated in the treatment tank 2.

[0080] Moreover, in the treatment system 1B of this embodiment, it is possible to generate electricity and perform desulfurization treatment through the same steps as in the first embodiment.

[0081] [Third embodiment] FIG. 4 is a schematic explanatory diagram showing a processing system according to the third embodiment of the present invention. The treatment system 1C according to the third embodiment is configured similarly to the treatment system 1A according to the first embodiment, and further includes a contact efficiency improving means 5 for improving the contact efficiency between the electrode surface of the power generation unit 4 and the electrode reaction components including the reducing substances in the filtrate F. Note that the description of the same components as those in the first embodiment will be omitted.

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

[0083] (Means for improving contact efficiency) The contact efficiency improving means 5 is intended to improve the contact efficiency of the electrode reaction components with the surfaces of the electrodes 43a and / or 43b in the power generation section 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 the surface of the electrode 43a and / or the electrode 43b. Examples of the contact efficiency improving means 5 in this embodiment include those that increase the moving speed of the electrode reaction component with respect to the surface of the electrode 43a and / or the electrode 43b and those that increase the concentration of the electrode reaction component. Moreover, it is preferable that the contact efficiency improving means 5 utilizes a treatment process for treating the workpiece S. This allows the treatment means for the workpiece S to serve as the contact efficiency improving means 5, reducing incidental equipment related to improving the contact efficiency between the electrodes and the electrode reaction components, and significantly reducing running costs.

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

[0086] An example of the contact efficiency improving means 5 in this embodiment is the provision of a movement speed control means 6 for controlling the movement speed of the electrode reaction components on the surface of the electrode 43a and / or the electrode 43b.

[0087] The movement speed control means 6 may be capable of controlling the movement speed of the electrode reaction components relative to the surface of the electrode 43a and / or the electrode 43b, and at least increasing the movement speed of the electrode reaction components. Specifically, the movement speed control means 6 may be capable of controlling the flow rate when the filtrate F is supplied to the power generation unit 4, generating turbulence in the cells (the first cell 41a and the second cell 41b) of the power generation unit 4, and controlling the temperature related to the electrode reaction.

[0088] Here, when a means for controlling the flow rate of the entire filtrate F is used as the movement speed control means 6, it is expected that a large amount of power will be required to control the flow rate, taking into consideration the total amount of the filtrate F. Therefore, the movement speed control means 6 is preferably one that can form turbulence in the cells of the power generation section 4 and increase the movement rate of the electrode reaction components. Furthermore, it is more preferable that the movement speed control means 6 form turbulence in the vicinity of the electrode surface in the power generation section 4. This makes it possible to reduce the power required to control the movement rate of the electrode reaction components, thereby enabling energy and cost savings.

[0089] A specific example of the movement speed control means 6 is to supply a fluid (gas or liquid) to the surfaces of the electrodes 43a and 43b to form a turbulent flow. Fig. 5 is a schematic explanatory diagram when a device that supplies a fluid to the surfaces of the electrodes 43a and 43b is used as the moving speed control means 6 of this embodiment. Note that Fig. 5 is an enlarged view of the periphery of the power generation unit 4 in the processing system 1C, and the processing tank 2 and the solid-liquid separation unit 3 are omitted from the illustration.

[0090] As shown in Fig. 5, the movement speed control means 6 may be provided with fluid supply ports 61a, 61b and fluid supply means 62 in the first cell 41a and the second cell 41b, respectively, and arranged so that the fluid is supplied near the surfaces of the electrodes 43a and 43b. The dashed arrows in Fig. 5 indicate the movement direction of the fluid.

[0091] The fluid supplying means 62 is not particularly limited as long as it can supply a fluid. The fluid supplying means 62 may be provided with a device capable of compressing the fluid and supply a compressed fluid. By using a compressed fluid, it becomes possible to easily control the flow rate related to the formation of a turbulent flow near the surfaces of the electrodes 43a and 43b.

[0092] When gas is used as the fluid supplied from the fluid supply means 62, for example, gas generated in the treatment process for treating the material S may be supplied, or a portion of the gas used in the treatment process for treating the material S may be diverted and supplied. More specifically, biogas generated in the treatment tank 2 may be collected and supplied from the fluid supply ports 61a, 61b, or a portion of the aeration gas when an aeration tank is provided as the treatment equipment for the treated water W2 may be supplied from the fluid supply ports 61a, 61b. This allows the gas supply source to be shared between the treatment means for the material S and the moving speed control means 6, making it possible to reduce treatment costs.

[0093] Furthermore, when a liquid is used as the fluid supplied from the fluid supply means 62, for example, a part of the liquid used in the treatment process for the workpiece S may be used. More specifically, a part of the treatment water W2 in the discharge pipe L5 may be supplied from the fluid supply ports 61a, 61b. This allows the liquid supply source to be shared between the treatment means for the workpiece S and the movement speed control means 6, thereby reducing the treatment cost.

[0094] As another embodiment of the movement speed control means 6, instead of providing the fluid supply ports 61a and 61b shown in Fig. 5 as separate bodies, the treated water inlet 42a, the treated water outlet 42b, the electron acceptor supply port 44a, and the electron acceptor outlet 44b can be used as the fluid supply ports 61a and 61b. This eliminates the need to provide a new structure as the contact efficiency improving means 5 (movement speed control means 6) in the power generation unit 4, making it possible to reduce equipment costs.

[0095] In addition, in the movement speed control means 6, the fluid supplied into the first cell 41a and the second cell 41b may be discharged directly from the outlet 42b and the electron acceptor outlet 44b together with the treated water and the electron acceptor, etc., or a recovery means 63 for recovering the supplied fluid may be provided. In particular, when the biogas generated from the treatment tank 2 is used as the fluid for the movement speed control means 6, it is preferable to provide the fluid recovery means 63. This allows the biogas used in the power generation unit 4 to be recovered and used again as an energy source, thereby making it possible to increase the energy recovery and utilization efficiency of the treatment system 1C.

[0096] The recovery means 63 is not particularly limited as long as it can discharge and recover the fluid in the movement speed control means 6 from the first cell 41a and the second cell 41b.

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

[0098] As shown in FIG. 6, the fluid recovery means 63 may include fluid outlets 64a and 64b provided in the first cell 41a and the second cell 41b, and the biogas supplied to the first cell 41a and the second cell 41b may be recovered from the fluid outlets 64a and 64b. Another example of the fluid recovery means 63 is a gas-liquid separator 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 FIG. 7, the gas-liquid separator 65 is provided on the discharge pipe L3 connected to the treated water outlet 42b, and the biogas supplied to the first cell 41a is recovered. In this case, as shown in FIG. 7, it is preferable that the inlet 42a and the outlet 42b are provided on the side of the first cell 41a, and the outlet 42b is provided at a position vertically higher than the inlet 42a. This makes it possible to efficiently recover the treated water W2 mixed with the fluid (biogas). Furthermore, it is preferable to provide equipment related to the utilization of the biogas, such as a gas storage facility (not shown), downstream of the recovery means 63 (the fluid discharge ports 64a and 64b, or the gas-liquid separation section 65). 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 (particularly hydrogen sulfide) contained in the biogas can be dissolved in the filtrate F, etc., and removed. This makes it possible to impart the function of biogas purification to the treatment system 1C in addition to wastewater treatment, power generation, and desulfurization treatment.

[0100] Another embodiment of the movement speed control means 6 is to provide a stirring mechanism in the first cell 41a and the second cell 41b to form a turbulent flow. This makes it possible to control the movement speed of the electrode reaction components relative to the electrode surface without providing a structure related to fluid supply from the outside. In addition, the movement speed of the electrode reaction components can be easily controlled by controlling the drive of the stirring mechanism.

[0101] Furthermore, as another embodiment of the moving speed control means 6, a temperature control means 66 may be provided. 8 to 10 are schematic explanatory diagrams when a temperature control means 66 is provided as the moving speed control means 6 of this embodiment. Note that Figs. 8 to 10 are enlarged views of the periphery of the power generation section 4 in the processing system 1C, and the processing tank 2 and the solid-liquid separation section 3 are omitted from the illustration.

[0102] As described above, an electrode reaction using the reducing substance in the filtrate F as an electron donor proceeds in the power generation section 4. Generally, it is known that an increase in temperature in an electrode reaction improves the mass transfer rate and the reaction efficiency. Therefore, by providing a temperature control means 66 for controlling the temperature related to the electrode reaction in the treatment system 1C as the movement speed control means 6, it is possible to improve the efficiency of the electrode reaction and increase the power generation efficiency and desulfurization treatment efficiency.

[0103] There are no particular limitations on the temperature control means 66 as long as it can adjust the temperature related to the power generation section 4. For example, it can adjust the temperature of the power generation section 4 itself, or adjust the temperature of the solution (filtrate F, etc.) introduced into the power generation section 4. As the temperature control means 66, a heat source may be newly 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 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] As the temperature control means 66 in this embodiment, an existing heat exchanger 67 installed to advance the anaerobic treatment in the treatment tank 2 may be used. For example, as shown in FIG. 8, the power generation unit 4 may be provided near the existing heat exchanger 67, and the cells (first cell 41a and second cell 41b), electrodes (electrodes 43a and 43b), introduction pipe L3, introduction port 42a, and electron acceptor supply port 44a of the power generation unit 4 may be arranged so that heat is supplied from the existing heat exchanger 67 to the cells, electrodes, introduction pipe L3, introduction port 42a, and electron acceptor supply port 44a of the power generation unit 4, thereby heating the power generation unit 4 itself and the filtrate F and electron acceptor introduced into the power generation unit 4. This makes it possible to control the temperature of the site where the reaction with the reducing substance in the filtrate F as the electron donor is performed and the substance used in the reaction, without installing new equipment related to temperature control, and to control the migration speed of the electrode reaction component to the electrode surface.

[0105] Another example of the temperature control means 66 is, as shown in FIG. 9, a method in which pipes 68a and 68b are provided to connect an existing heat exchanger 67 and the power generation unit 4, and a heat medium such as air or water is moved through the pipes 68a and 68b to supply heat from the existing heat exchanger 67 to the power generation unit 4. This makes it possible to control the temperature of the power generation unit 4, control the temperature at the location where the reaction is carried out with the reducing substance in the filtrate F as the electron donor, and control the movement speed of the electrode reaction component to the electrode surface. Note that there is no particular limitation on the means for connecting the pipes 68a and 68b to the power generation unit 4. For example, the pipes 68a and 68b may be arranged so as to surround the entire power generation unit 4, or the pipes 68a and 68b may be arranged so as to contact one of the components of the power generation unit 4 (the electrodes 43a and 43b, or the first cell 41a and the second cell 41b). 10, another example of the temperature control means 66 is to provide pipes 69a, 69b connecting an existing heat exchanger 67 and the inlet pipe L3, and supply heat from the existing heat exchanger 67 to the filtrate F in the inlet pipe L3 by moving a heat medium such as air or water through the pipes 69a, 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 in which the reducing substance in the filtrate F serves as an electron donor, and control the movement speed of the electrode reaction component to the electrode surface. Furthermore, the point where the pipes 69a and 69b are connected may be the electron acceptor supply port 44a instead of the inlet pipe L3. This makes it possible to supply heat from the existing heat exchange equipment 67 to the electron acceptor, control the temperature of the substance (electron acceptor) used in the reaction in which the reducing substance in the filtrate F serves as the electron donor, and control the migration speed of the electrode reaction component to the electrode surface. 9 and 10 may be provided individually or in combination, and can be appropriately selected in consideration of the temperature control efficiency of the temperature control means 66 and the cost of the equipment.

[0106] Another example of the temperature control means 66 is to use exhaust heat from gas power generation using biogas (such as methane generated by methane fermentation) generated from the treatment tank 2, instead of the existing heat exchange equipment 67. More specifically, a heat medium such as air or water heated using this exhaust heat is brought into contact with the power generation unit 4 or the inlet pipe L3 through a pipe to supply heat, thereby making it possible to control the temperature related to the reaction in which the reducing substance in the filtrate F serves as an electron donor. This improves the power generation efficiency and the desulfurization treatment efficiency, and enables the effective use of exhaust heat related to methane gas power generation.

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

[0108] The concentration control means 7 can be configured to control the concentration of the electrode reaction component in the power generation unit 4 and at least increase the concentration of the electrode reaction component. Specifically, the concentration control means 7 can be configured to additionally supply the electrode reaction component to the power generation unit 4, to collect the electrode reaction component in the power generation unit 4 near the electrodes 43a and 43b, and to maintain environmental conditions that allow the electrode reaction component to be dissolved in the filtrate F.

[0109] A specific example of the concentration control means 7 is to additionally supply an electrode reaction component into the first cell 41a and the second cell 41b. Fig. 11 is a schematic explanatory diagram when a concentration control means 7 for additionally supplying an electrode reaction component into the first cell 41a and the second cell 41b is used in this embodiment. Note that Fig. 11 is an enlarged view of the periphery of the power generation section 4 in the treatment system 1C, and the treatment tank 2 and the solid-liquid separation section 3 are omitted from the illustration.

[0110] As shown in FIG. 11, the concentration control means 7 may be provided with electrode reaction component addition ports 71a, 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 additionally supply the 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 unit for storing the electrode reaction components, a control unit for determining and adjusting the amount of the electrode reaction components to be added, and the like.

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

[0113] In addition, by using an electrode reaction component as the fluid in the above-mentioned moving speed control means 6, it may also function as the electrode reaction component adding 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 the biogas from the treatment tank 2 to the first cell 41a of the power generation unit 4 and use it as the fluid in the moving speed control means 6 and the electrode reaction component in the electrode reaction component adding means 72. At this time, water-soluble components in the biogas (particularly hydrogen sulfide) dissolve in the filtrate F, increasing the concentration of reducing substances in the filtrate F, while making it possible to remove hydrogen sulfide from the biogas. This has the effect of improving the power generation efficiency and the desulfurization treatment efficiency, as well as providing the function of biogas purification.

[0114] Another specific example of the concentration control means 7 is to concentrate the electrode reaction components in the power generation unit 4 near the electrodes 43a and 43b. Fig. 12 is a schematic explanatory diagram when a concentration control means 7 for concentrating electrode reaction components in the vicinity of the electrodes 43a and 43b is used in this embodiment. Note that Fig. 12 is an enlarged view of the power generation unit 4 and its surroundings in the treatment system 1C, and the treatment tank 2 and solid-liquid separation unit 3 are not shown.

[0115] As shown in FIG. 12, the concentration control means 7 may include an adsorbent 73 provided in a first cell 41a and a second cell 41b.

[0116] The adsorbent 73 may be any material capable of adsorbing the electrode reaction component, and the material and shape of the adsorbent 73 are not particularly limited. For example, the first cell 41a may be provided with an adsorbent 73 capable of adsorbing a reducing substance as the electrode reaction component. On the other hand, the second cell 41b may be provided with an adsorbent 73 capable of adsorbing an electron acceptor as the electrode reaction component. The adsorbent 73 may be provided in the vicinity of the electrodes 43a and 43b, or the electrodes 43a and 43b may be made of porous material, and the electrodes 43a and 43b themselves may function as the adsorbent 73. This allows the electrode reaction component to be concentrated in the vicinity of the electrodes 43a and 43b, and the concentration of the electrode reaction component to be controlled.

[0117] Furthermore, another specific example of the concentration control means 7 is to maintain environmental conditions that allow the electrode reaction components to be dissolved in the filtrate F. Fig. 13 is a schematic explanatory diagram when the concentration control means 7 of this embodiment maintains environmental conditions for dissolving the electrode reaction components in the filtrate F. Note that Fig. 13 is an enlarged view of the periphery of the power generation unit 4 in the treatment system 1C, and the treatment tank 2 and solid-liquid separation unit 3 are not shown.

[0118] As described above, in the treatment tank 2, hydrogen sulfide, which is a reducing substance, is generated as the anaerobic treatment (such as methane fermentation treatment) progresses. On the other hand, it is known that the solubility of hydrogen sulfide in a solution changes depending on the pH, and that the solubility increases when the solution is made alkaline, at pH 6 or higher, and the release of hydrogen sulfide out of the solution is suppressed. Therefore, by providing a pH control means 74 that adjusts the pH of the treatment liquid W1 and the filtrate F, it is possible to change the solubility of reducing substances (particularly hydrogen sulfide) and maintain environmental conditions that allow the reducing substances in the filtrate F to be dissolved in the filtrate F. This increases the amount of reducing substances in the filtrate F and increases the amount of electron donor provided for the reaction, making it possible to improve the power generation efficiency and desulfurization treatment efficiency in the power generation unit 4.

[0119] The pH control means 74 is not particularly limited as long as it can adjust the pH of the treatment liquid W1 or the filtrate F and dissolve the reducing substances in the filtrate F in the filtrate F. As shown in FIG. 12, the pH control means 74 may include a storage section 75 for storing a pH adjuster, an addition section 76 for adding the pH adjuster to the filtrate F, and a pH detection section 77.

[0120] The storage section 75 is not particularly limited as long as it can store a pH adjuster. The pH adjuster stored in the storage section 75 is also not particularly limited, and it is preferable to select the type of pH adjuster according to the pH dependency of the solubility of the reducing substance. For example, when the reducing substance is hydrogen sulfide, a pH adjuster that makes the pH of the filtrate F more alkaline can be used to increase the solubility of hydrogen sulfide. More specifically, a hydroxide such as sodium hydroxide or calcium hydroxide can be used as the pH adjuster. An acid such as hydrochloric acid or sulfuric acid can also be used as the pH adjuster.

[0121] The addition unit 76 is for adding the pH adjuster in the storage unit 75 to the filtrate F. In this embodiment, the addition unit 76 is provided on the inlet pipe L3 as shown in FIG. 13. In this case, the addition unit 76 is not particularly limited as long as it has a structure capable of adding the pH adjuster to the filtrate F in the inlet pipe L3. For example, the addition unit 76 may be a pipe that connects the inlet pipe L3 and the storage unit 75 and has a flow rate adjustment function.

[0122] The position of the addition unit 76 is not particularly limited, but it is preferable to select a position where the pH of the filtrate F can be adjusted and the solubility of the reducing substances can be appropriately controlled. For example, as shown in FIG. 13, the addition unit 76 may be provided on the inlet pipe L3, or on the connection 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 introduced into the solid-liquid separation unit 3 while being dissolved in the treated liquid W1. As a result, the filtrate F can be introduced into the power generation unit 4 while maintaining the environmental conditions that allow the reducing substances in the filtrate F to be dissolved in the filtrate F.

[0123] Another example of the pH control means 74 is to utilize other equipment in the treatment system. Fig. 14 is a schematic explanatory diagram showing another example of the pH control means in the concentration control means 7 of this embodiment. Note that Fig. 14 is an enlarged view of the periphery of the power generation unit 4 in the treatment system 1C, and the treatment tank 2 and the solid-liquid separation unit 3 are omitted from the illustration. As shown in Fig. 14, the pH control means 74 may be provided with a storage section 46 that circulates and supplies treated water W2 to the power generation section 4, and a connection pipe L6 that supplies gas G (biogas) generated in the treatment tank 2 to the storage section 46 (see Fig. 3), and the treated water W2 into which the gas G has been introduced is used as a pH adjuster. In this case, the storage section 46 also functions as the above-mentioned reservoir section 75. This eliminates the need to provide a new structure as the pH control means 74, and makes it possible to improve power generation efficiency and desulfurization efficiency while also purifying the biogas generated in the treatment tank 2.

[0124] As shown in FIG. 13, it is preferable to provide a pH detector 77 on the inlet pipe L3 and control the amount of pH adjuster added from the addition unit 76 according to the detection result of the pH detector 77. The pH detector 77 may also be provided on the reservoir 75 (reservoir 46) or the circulation flow path 47 (not shown) shown in FIG. 14 to adjust the circulation amount of the treated water W2. This makes it easier to adjust the pH of the filtrate F and allows it to be performed 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 provided for the reaction, thereby improving the power generation efficiency and desulfurization treatment efficiency in the power generation unit 4. There is no particular limitation on the means for controlling the addition unit 76 and the means for adjusting the circulation amount of the treated water W2 in response to the detection result of the pH detection unit 77. For example, an operator may visually check the detection result of the pH detection unit 77 and manually operate the addition unit 76 or the circulation flow path 47 of the treated water W2 in response to the result, or the pH detection unit 77 and the addition unit 76 (or the circulation flow path 47) may be controllably connected to automatically control the pH detection of the filtrate F and the addition of the pH adjuster (or the circulation amount of the treated water W2).

[0125] The contact efficiency improving means 5 in this embodiment can set the operating conditions as appropriate. For example, it may be operated constantly when the power generation unit 4 is driven (power generation), or the interval or timing of operation may be changed periodically or irregularly. This allows the operating conditions to be set that enable efficient power generation and desulfurization by the treatment system 1C, enabling efficient recovery and utilization of energy and improvement of the desulfurization efficiency.

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

[0127] As described above, in the treatment system 1C of this embodiment, by providing a contact efficiency improving means for improving 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 to improve the efficiency of power generation and desulfurization treatment.

[0128] Moreover, in the treatment system 1C of this embodiment, it is possible to generate electricity and perform desulfurization treatment through the same steps as in the first embodiment.

[0129] In particular, by providing a moving speed control means for controlling the moving speed of the electrode reaction components to the electrode surface as the contact efficiency improving means in the treatment system 1C of this embodiment, it becomes possible to quickly supply the electrode reaction components to the electrode surface, thereby improving the contact efficiency between the electrode surface and the electrode reaction components, suppressing the decrease in the efficiency of the electrode reaction, and improving the power generation efficiency.

[0130] In addition, by providing a concentration control means for controlling the concentration of the electrode reaction component as the contact efficiency improving means in the treatment system 1C of this embodiment, it becomes possible to increase the amount of the electrode reaction component involved in the electrode reaction. This makes it possible to improve the contact efficiency between the electrode surface and the electrode reaction component, suppress the decrease in the efficiency of the electrode reaction, and improve the power generation efficiency.

[0131] Furthermore, by using a means for improving contact efficiency in the treatment system 1C of this embodiment that serves both as the above-mentioned moving speed limiting means and concentration control means, it is possible to further suppress a decrease in the efficiency of the electrode reaction. In particular, by utilizing the biogas generated in the treatment tank and using it as a fluid for forming turbulence in the moving speed control means and as an electrode reaction component for additional supply in the concentration control means, it is 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 (particularly hydrogen sulfide) in the biogas. Therefore, the treatment system 1C of this embodiment has the effect of being equipped with a function of biogas purification in addition to wastewater treatment, power generation, and desulfurization treatment.

[0132] [Fourth embodiment] The processing system 1D according to the fourth embodiment is different from the processing system 1A according to the first embodiment in that a cleaning means 8 for cleaning deposits deposited on the surfaces of the electrodes 43a and 43b is provided as a contact efficiency improving means 5. Note that the description of the same components as those in the first and third embodiments will be omitted.

[0133] As shown in formulas 1 and 2, products (such as sulfur) produced by the electrode reaction and microorganisms partially flowing into the power generation unit 4 adhere to the surface of the electrode 43a and accumulate as deposits. At this time, the mass transfer rate of the reducing substance to the electrode 43a is hindered by the deposits, causing a problem of a decrease in the electrode reaction efficiency. Similarly, in the electrode 43b, substances introduced as electron acceptors and mixed impurities adhere to the electrode 43b and accumulate as deposits, causing a problem of a decrease in the efficiency of the electrode reaction. Therefore, by providing the cleaning means 8 as the contact efficiency improving means 5, the 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 the electrode reaction efficiency in the power generation unit 4 can be suppressed, and the power generation efficiency and the desulfurization treatment efficiency can be improved.

[0134] The cleaning means 8 is for cleaning the surfaces of the electrodes 43a and 43b in the power generation section 4, and suppressing a decrease in the electrode reaction efficiency. The cleaning means 8 is not particularly limited as long as it can remove deposits accumulated on the surfaces of the electrodes 43a and 43b. Examples of the cleaning means 8 in this embodiment include a means for cleaning the electrodes 43a and 43b while they are still in the power generation unit 4, and a means for cleaning the electrodes 43a and 43b after removing them from the power generation unit 4. However, it is possible to appropriately select a cleaning means 8 in consideration of the cleaning effect, ease of operation, and the like.

[0135] A specific example of the cleaning means will be described below. Note that the following description of the cleaning means 8 is merely an example of the cleaning means 8 in this embodiment, and is not intended to be limiting.

[0136] The cleaning means 8 in this embodiment includes a removing means 8A that applies an external force to the deposits deposited on the electrode surface to remove them. The peeling means 8A may be any means capable of peeling off the deposits by applying an external force to them, and may be, for example, a means for mechanically rubbing the surfaces of the electrodes 43a and 43b, or a means for applying a shear force by gas or liquid to the deposits deposited on the surfaces of the 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 the electrodes 43a and 43b, and a high cleaning effect can be obtained regardless of the type of deposits. In addition, by using the peeling means 8A, cleaning can be performed without changing the environmental conditions (pH, concentration of various compounds, etc.) in the first cell 41a and the second cell 41b by the cleaning means 8.

[0137] A specific example of the peeling means 8A is a member such as a sponge or a scraper that scrapes the surfaces of the electrodes 43a and 43b. As an example of using a member for rubbing the surfaces of the electrodes 43a and 43b, a driving unit and a control unit are provided so that the surfaces of the electrodes 43a and 43b can be automatically rubbed, and the frequency and timing of cleaning can be set. This makes it easy to clean the deposits that have accumulated on the surfaces of the electrodes 43a and 43b. In addition, by periodically moving the member, it is possible to prevent the deposits from accumulating on the surfaces of the electrodes 43a and 43b. Another example of using a member for rubbing the surfaces of the electrodes 43a and 43b is to have an operator directly wash the surfaces of the electrodes 43a and 43b, which enables the operator to perform visual maintenance while washing the surfaces of the electrodes 43a and 43b.

[0138] Another specific example of the peeling means 8A is to apply air bubbles or compressed fluid (gas or liquid) to the surfaces of the electrodes 43a and 43b. Fig. 15 is a schematic explanatory diagram of a case where a fluid (gas or liquid) is applied to the surfaces of the electrodes 43a and 43b as the peeling means 8A in this embodiment. Note that Fig. 15 is an enlarged view of the power generation unit 4 and its surroundings in the treatment system 1D, and the treatment tank 2 and solid-liquid separation unit 3 are not shown.

[0139] As shown in Fig. 15, the peeling means 8A may be provided with fluid supply ports 81a, 81b and a fluid supply means 82 in the first cell 41a and the second cell 41b, respectively, and arranged so that the fluid hits the surfaces of the electrodes 43a and 43b. The dashed arrows in Fig. 15 indicate the movement direction of the fluid. The fluid supply ports 81a, 81b and the fluid supply means 82 may have the same structure as the fluid supply ports 61a, 61b and the fluid supply means 62 in the above-mentioned movement speed control means 6, and may function both as the movement speed control means 6 and the peeling means 8A.

[0140] The fluid supply means 82 is not particularly limited as long as it can supply a fluid.

[0141] When gas is used as the fluid supplied from the fluid supply means 82, for example, gas generated in the treatment process for treating the material S may be supplied, or a part of the gas used in the treatment process for treating the material S may be used. More specifically, biogas generated in the treatment tank 2 may be collected and supplied from the fluid supply ports 81a and 81b, or a part of the aeration gas when an aeration tank is provided as the treatment equipment for treating the treated water W2 may be supplied from the fluid supply ports 81a and 81b. This allows the treatment means for the material S to be treated and the cleaning means 8 to share a gas supply source, which makes it possible to reduce treatment costs. In this case, the fluid supply means 82 may be provided with equipment (such as a blower or compressor) capable of compressing gas to supply compressed gas. By using compressed gas, the shear force on the deposits accumulated on the surfaces of the electrodes 43a and 43b is strengthened, and the cleaning effect can be improved.

[0142] In addition, when a liquid is used as the fluid supplied from the fluid supply means 82, for example, a part of the liquid used in the treatment process for the workpiece S may be used. More specifically, a part of the treatment water W2 in the discharge pipe L5 may be supplied from the fluid supply ports 81a, 81b. This allows the treatment means for the workpiece S to be used as a liquid supply source for the cleaning means 8, and reduces the treatment cost. In this case, the fluid supply means 82 may be provided with equipment (such as a high-pressure pump) capable of compressing the liquid, and may supply high-pressure liquid. By using high-pressure liquid, the shear force on the deposits accumulated on the surfaces of the electrodes 43a and 43b is strengthened, and the cleaning effect can be improved.

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

[0144] In another embodiment of the peeling means 8A, instead of providing the fluid supply ports 81a and 81b shown in Fig. 15 as separate bodies, the inlet 42a, the outlet 42b, the electron acceptor supply port 44a, and the electron acceptor outlet 44b can be used as the fluid supply ports 81a and 81b. This eliminates the need to provide a new structure as the cleaning means 8 in the power generation unit 4, making it possible to reduce equipment costs.

[0145] Fig. 16 is a schematic explanatory diagram showing another example of the peeling means 8A of this embodiment. Note that Fig. 16 is an enlarged view of the periphery of the power generation section 4 in the treatment system 1D, and the treatment tank 2 and the solid-liquid separation section 3 are omitted. Also, the dashed arrow in Fig. 16 indicates the movement direction of the fluid.

[0146] As shown in FIG. 16, the peeling means 8A may be, for example, provided with pumps P1 and P2 capable of pressurizing liquid on the inlet pipe L3 and the outlet pipe L5, and may be used to supply high-pressure liquid to the surface of the electrode 43a for cleaning. At this time, the high-pressure liquid may be supplied from the inlet pipe L3 side toward the inlet 42a, or from the outlet pipe L5 side toward the outlet 42b. At this time, as shown in FIG. 16, a control unit 83 may be provided to switch between the drive of the pump P1 on the inlet pipe L3 and the pump P2 on the outlet pipe L5. This allows easy switching between the normal wastewater treatment process and the cleaning process. In addition, the high-pressure liquid may be supplied alternately from the inlet pipe L3 side and the outlet pipe L5 side. This makes it possible to improve the cleaning effect of the surface of the electrode 43a.

[0147] 16, the peeling means 8A may, for example, supply compressed fluid from an electron acceptor supply port 44a and an electron acceptor discharge port 44b to clean the surface of the electrode 43b. At this time, gas generated from the treatment process for the workpiece S or fluid used in the treatment of the workpiece S may be compressed and supplied by a pump or the like (not shown). This makes it possible to minimize the structure newly installed as the peeling means 8A and reduce equipment costs.

[0148] In addition, in the peeling means 8A, the fluid supplied into the first cell 41a and the second cell 41b may be discharged from the outlet 42b and the electron acceptor outlet 44b after cleaning, or 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 of the peeling means 8A, it is preferable to collect the fluid after cleaning from the fluid outlet. In addition, when collecting the fluid after cleaning, a structure similar to the above-mentioned collection means 63 may be provided. This allows the fluid after cleaning to be collected and used again as biogas, and the energy recovery and utilization efficiency of the treatment system 1D can be improved.

[0149] Another aspect of the cleaning means 8 in this embodiment is one equipped with dissolving means 8B for dissolving deposits that have accumulated on the electrode surface. The dissolving means 8B may be any means capable of dissolving deposits, and examples of such means include a means for adding a chemical agent for dissolving deposits to the electrodes 43a and 43b, and an electrochemical means for controlling the voltage and current between the electrodes 43a and 43b. By using the dissolving means 8B as the cleaning means 8, the number of newly added device components is small, and the equipment can be made smaller. In addition, particularly when the surfaces of the electrodes 43a and 43b are porous, a high cleaning effect is achieved on deposits accumulated on and inside the electrodes 43a and 43b.

[0150] A specific example of the dissolving means 8B is the addition of a chemical that dissolves the deposits. Fig. 17 is a schematic explanatory diagram of the dissolving means 8B of this embodiment, which adds a chemical to the surfaces of the electrodes 43a and 43b. Fig. 17 is an enlarged view of the power generation unit 4 and its surroundings in the treatment system 1D, and the treatment tank 2 and solid-liquid separation unit 3 are omitted.

[0151] As shown in Fig. 17, an example of using a dissolving means 8B that adds a drug is to provide drug addition ports 84a, 84b and drug addition means 85 in the first cell 41a and the second cell 41b, respectively, and arrange them so that a drug is supplied to the deposits accumulated on the surfaces of the electrodes 43a and 43b. The dashed arrow in Fig. 17 indicates the direction in which the drug is added.

[0152] There is no particular limitation on the chemical addition means 85 as long as it can add a chemical to the first cell 41a and the second cell 41b. For example, the chemical addition means 85 may include a storage unit for storing the chemical, a control unit for determining and adjusting the amount of chemical to be added, and the like.

[0153] The type of chemical added by the chemical adding means 85 is not particularly limited as long as it can dissolve the deposits. Examples of chemicals that can be used include acids such as hydrochloric acid and sulfuric acid, and alkalis such as an aqueous solution of sodium hydroxide. Chemicals such as pH adjusters used in the treatment process for treating the workpiece S may also be used. This eliminates the need to prepare new chemicals for the cleaning means 8, making it possible to reduce running costs.

[0154] When the dissolving means 8B includes the chemical addition ports 84a and 84b and the chemical addition means 85, it is preferable that the chemical addition direction is from the top to the bottom of the electrodes 43a and 43b, as shown in Fig. 17. In particular, when the contents stored in the first cell 41a and the second cell 41b are liquids, the chemical is added from the top of the electrodes 43a and 43b, so that the chemical is quickly diffused in the cells 41a and 41b. This allows the chemical to be efficiently distributed over the entire surfaces of the electrodes 43a and 43b, thereby enhancing the cleaning effect.

[0155] Also, a chemical supplying means 85 may be connected to the inlet pipe L3 to supply the chemical to the electrode 43a from the inlet 42a. This eliminates the need to provide a separate chemical supplying port 84a, making it possible to simplify the device configuration.

[0156] Another embodiment of the dissolving means 8B is to provide a voltage / current control device connected to the electrodes 43a and 43b and perform electrochemical treatment. More specifically, a high voltage is applied between the electrodes 43a and 43b, or a current is passed in the opposite direction to the electrode reaction during power generation. In this way, when the electrodes 43a and 43b are porous, it becomes possible to effectively dissolve the deposits that have accumulated on the surfaces and in the porous portions of the electrodes 43a and 43b. In particular, when the deposits are mainly formed by the electrode reaction, the deposits can be forcibly oxidized (or reduced) by passing a current in the opposite direction to the electrode reaction during power generation, and a high cleaning effect is achieved.

[0157] Another aspect of the cleaning means 8 in this embodiment is one equipped with a dispersing means 8C for dispersing and scattering deposits that have accumulated on the electrode surface. The dispersion means 8C may be any means capable of dispersing deposits on the electrode surface and dispersing the deposits from the electrode surface, and may be, for example, a means for adding a chemical having a deposit dispersing effect to the electrodes 43a and 43b, or a means for applying vibration to the surfaces of the electrodes 43a and 43b. By using the dispersion means 8C as the cleaning means 8, the deposits are dispersed once and disperse from the surfaces of the electrodes 43a and 43b, so that cleaning can be performed with a small load on the surfaces of the electrodes 43a and 43b. In addition, when the electrodes 43a and 43b are porous, a high cleaning effect is achieved even for deposits deposited in the porous areas.

[0158] A specific example of the dispersing means 8C is the addition of a chemical that has the effect of dispersing sediments. Fig. 18 is a schematic explanatory diagram when a dispersion means 8C for adding a chemical to the surfaces of the electrodes 43a and 43b is used in this embodiment. Note that Fig. 18 is an enlarged view of the periphery of the power generation unit 4 in the treatment system 1D, and the treatment tank 2 and solid-liquid separation unit 3 are omitted.

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

[0160] There is no particular limitation on the chemical addition means 87 as long as it can add a chemical to the first cell 41a and the second cell 41b. For example, the chemical addition means 87 may include a storage unit for storing the chemical, a control unit for determining and adjusting the amount of chemical to be added, and the like.

[0161] The type of the chemical added by the chemical adding means 87 is not particularly limited as long as it can disperse the deposits. Examples of chemicals include surfactants and enzymes. The chemicals used in this case have a small effect on the electrodes 43a and 43b, such as corrosion, and have the effect of not applying more load than necessary to the surfaces of the electrodes 43a and 43b. In particular, when the deposits are mainly composed of microorganisms, the use of surfactants and enzymes can disperse the microorganisms on the surfaces of the electrodes 43a and 43b, and disperse the microorganisms from the surfaces of the electrodes 43a and 43b. This makes it possible to prevent the dead microorganisms on the surfaces of the electrodes 43a and 43b from remaining as deposits, and to suppress a decrease in the electrode reaction efficiency.

[0162] When the chemical addition ports 86a, 86b and the chemical addition means 87 are provided as the dispersion means 8C, it is preferable that the chemical addition direction is from the top to the bottom of the electrodes 43a and 43b as shown in Fig. 16. In particular, when the substance stored in the first cell 41a and the second cell 41b is liquid, the chemical is added from the top of the electrodes 43a and 43b, so that the chemical is quickly diffused in the cells 41a and 41b. This allows the chemical to be efficiently distributed over the entire surface of the electrodes 43a and 43b, thereby enhancing the cleaning effect.

[0163] Also, a chemical supplying means 87 may be connected to the inlet pipe L3 to supply the chemical to the electrode 43a from the inlet 42a. This eliminates the need to provide a separate chemical supplying port 86a, making it possible to simplify the device configuration.

[0164] Another embodiment of the dispersing means 8C is to vibrate the electrodes 43a and 43b. More specifically, an ultrasonic generator may be provided so that ultrasonic waves can be applied to the electrodes 43a and 43b. This allows the deposits accumulated on the surfaces of the electrodes 43a and 43b to be broken down and dispersed, and to be separated from the surfaces of the electrodes 43a and 43b. In particular, when the deposits are a collection of microorganisms or when the products of the electrode reaction are in the form of clumps, the deposits can be broken down once by ultrasonic waves, and therefore the deposits can be easily peeled off without applying a load to the surfaces of the electrodes 43a and 43b.

[0165] Another aspect of the cleaning means 8 in this embodiment is one equipped with surrounding environment changing means 8D for changing the surrounding environment of the electrode surface. The surrounding environment changing means 8D may be anything that changes the surrounding environment of the electrode surface, and examples of such means 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 deposits. By using the surrounding environment changing means 8D as the cleaning means 8, if the deposits contain microorganisms, the microorganisms cannot withstand the environmental changes around the electrode surface, and it becomes possible to spontaneously move the microorganisms in a direction away from the electrode surface. This makes it possible to effectively peel off the microorganisms from the electrode surface, and a high cleaning effect can be obtained for the electrode surface.

[0166] A specific example of the surrounding environment changing means 8D is supplying an additive that changes the physical properties inside the first cell 41a and the second cell 41b. Fig. 19 is a schematic explanatory diagram of the case where an additive is supplied to the surfaces of the electrodes 43a and 43b as the surrounding environment changing means 8D of this embodiment. Note that Fig. 19 is an enlarged view of the periphery of the power generation section 4 in the treatment system 1D, and the treatment tank 2 and the solid-liquid separation section 3 are omitted.

[0167] As shown in Fig. 19, an example of using an additive supplying device as the surrounding environment changing device 8D is to provide additive supply ports 88a, 88b and additive supplying device 89 in the first cell 41a and the second cell 41b, respectively, to change the surrounding environment of the surfaces of the electrodes 43a and 43b and the accumulated deposits. The dashed arrow in Fig. 19 indicates the additive supplying direction.

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

[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 in the first cell 41a and the second cell 41b. Examples of additives include salts such as sodium chloride and potassium chloride, and ion-free additives such as electrolytic water. This can change the salt concentration in the first cell 41a and the second cell 41b, which changes the osmotic pressure around the surfaces of the electrodes 43a and 43b, thereby encouraging the spontaneous migration of microorganisms from the surfaces of the electrodes 43a and 43b.

[0170] When the additive supply ports 88a, 88b and the additive supply means 89 are provided as the surrounding environment changing means 8D, it is preferable that the additive is supplied from the upper part to the lower part of the electrodes 43a and 43b as shown in Fig. 19. In particular, when the substance stored in the first cell 41a and the second cell 41b is liquid, the additive is supplied from the upper part of the electrodes 43a and 43b, so that the additive spreads along the surfaces of the electrodes 43a and 43b. This makes it possible to effectively change the physical properties around the surfaces of the electrodes 43a and 43b, and to enhance the cleaning effect.

[0171] Another aspect of the surrounding environment changing means 8D is to give a certain amount of damage to the deposits. More specifically, when the deposits on the surfaces of the electrodes 43a and 43b are microorganisms, chlorine or ozone can be supplied to the microorganisms, or ultraviolet rays can be irradiated. This can give a certain amount of damage to the deposits (microorganisms) deposited on the surfaces of the electrodes 43a and 43b. At this time, the microorganisms cannot withstand the environmental change of being damaged, and it is possible to encourage them to move spontaneously from the surfaces of the electrodes 43a and 43b. Note that if the amount of chlorine or ozone supplied or the amount of ultraviolet rays irradiated becomes excessive, the microorganisms will die on the surfaces of the electrodes 43a and 43b and remain as deposits. Therefore, it is preferable to suppress the amount of chlorine or ozone supplied or the amount of ultraviolet rays irradiated, which also has the effect of reducing running costs.

[0172] The cleaning means 8 in the processing system 1D of this embodiment is not limited to the above-mentioned peeling means 8A, dissolving means 8B, dispersing means 8C, and surrounding environment changing means 8D performed individually, and may be a combination of a plurality of the above-mentioned means 8A to 8D. This makes it possible to select and perform a suitable cleaning means 8 according to the type of deposit, and a higher cleaning effect can be obtained. In particular, in the means 8B to 8D of the cleaning means 8, in the configuration in which a chemical agent, additive, etc. is added to the first cell 41a and the second cell 41b, it is possible to perform each of the means 8B to 8D by simply changing the chemical agent or additive to be added. Therefore, the means 8B to 8D can be easily switched according to the type of deposit, and effective cleaning can be performed.

[0173] As described above, in the treatment system 1D of this embodiment, by providing a cleaning means for cleaning deposits accumulated on the electrode surface as a contact efficiency improving means, 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] Moreover, in the treatment system 1D of this embodiment, it is possible to generate electricity and perform desulfurization treatment by the same steps as in the first embodiment.

[0175] Furthermore, in the power generation unit 4 of the treatment system 1D of this embodiment, accumulation of deposits on the electrode surfaces may cause a reduction in the volume of the cells (first cell 41a and second cell 41b) in the power generation unit 4 and clogging of the electrodes (electrodes 43a and 43b), which may result in pressure loss. Therefore, as in the treatment system 1D of this embodiment, a cleaning means is provided as a contact efficiency improving means to remove deposits on the electrode surfaces, thereby making it possible to suppress pressure loss within the device.

[0176] [Fifth embodiment] Fig. 20 is a schematic explanatory diagram showing a processing system according to the fifth embodiment of the present invention, and Fig. 21 is a schematic explanatory diagram showing another aspect of the processing system according to the fifth embodiment of the present invention. As shown in Fig. 20 and Fig. 21, the treatment system 1E according to the fifth embodiment is the treatment system 1A according to the first embodiment, except that an exhaust gas supply means 9 is provided as a means for suppressing an increase in pH on the cathode side. Note that the description of the same components as those in the first embodiment will be omitted. Fig. 20 and Fig. 21 are enlarged explanatory views of the power generation section 4 and its surroundings in the treatment system 1E, and the components related to the treatment tank 2 and solid-liquid separation section 3 are omitted.

[0177] As described above, in the electrode reaction in the treatment system of this embodiment, hydrogen ions (H + ) moves, and reaction R4 based on formula 3 proceeds. However, in reaction R3, hydrogen ions move via ion exchanger 45, so that the electrode reaction may proceed before sufficient hydrogen ions are supplied to electrode 43b on the cathode side for the reaction based on formula 3. At this time, at electrode 43b, instead of the reaction that produces water (HO) based on formula 3, hydroxide ions (OH - ) is produced, and the pH rises at the electrode 43b (cathode side). This causes a problem of a decrease in the efficiency of the electrode reaction.

[0178] For this reason, it is preferable to provide the treatment system with a means for suppressing an increase in pH on the cathode side of the power generation unit 4. An example of a means for suppressing an increase in pH is adding an acidic component. Here, as a more preferable example of a means for suppressing an increase in pH, other than providing a new means for adding an acidic component as a chemical, a configuration that can utilize waste discharged from an existing device or the like can be mentioned. This makes it possible to reduce the cost and energy of the treatment system 1E. As a means of utilizing the exhaust from existing equipment and suppressing the increase in pH, for example, exhaust gas generated from various combustion equipment can be supplied to the treatment system 1E. The exhaust gas generated from the combustion equipment contains carbon dioxide (CO2), sulfur oxides (SO X ), nitrogen oxides (NO X ), which are known to be acidic when dissolved in an aqueous solution. Therefore, by utilizing the exhaust gas generated in the combustion device, it is possible to suppress the increase in pH in the power generation unit 4.

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

[0180] A specific example of the exhaust gas supplying means 9 is a mechanism for directly supplying the exhaust gas generated in the combustion device to the second cell 41b in the power generating section 4. FIG. 20 is a schematic explanatory diagram of the case where a mechanism for supplying exhaust gas directly to the second cell 41b is provided as the exhaust gas supplying means 9 of this embodiment.

[0181] As shown in FIG. 20, the exhaust gas supplying means 9 may be provided with an exhaust gas supply port 91 in the second cell 41b, and a pipe 92 for supplying exhaust gas generated in a combustion device (not shown) may be connected to the exhaust gas supply port 91. Here, the dashed arrow in FIG. 20 indicates the inflow direction of the exhaust gas. Also, in FIG. 20, the exhaust gas supplying means 9 is illustrated as being provided with an exhaust gas supply port 91 in the upper part of the second cell 41b and supplying the exhaust gas, but is not limited thereto. As another example of the exhaust gas supplying means 9, for example, the exhaust gas supply port 91 may be provided in the lower part of the second cell 41b, and the exhaust gas may be supplied so as to rise from the lower part to the upper part of the second cell 41b.

[0182] The exhaust gas supply port 91 and the piping 92 may have a known structure for supplying and transferring gas, and the specific structure is not particularly limited. Furthermore, the piping 92 may be any piping that is capable of transporting exhaust gas generated in the combustion device, and may be either directly connected to the combustion device or indirectly connected thereto.

[0183] 20, the exhaust gas supplying means 9 is not limited to one provided with an exhaust gas supply port 91 and a pipe 92 for the power generation unit 4. For example, the exhaust gas supplying means 9 may be one in which a pipe 92 is connected to a storage location for the electron acceptor or to a line that supplies the electron acceptor, and exhaust gas is supplied from the electron acceptor supply port 44a to the electrode 43b. This eliminates the need to provide a separate exhaust gas supply port 91, making it possible to simplify the device configuration.

[0184] In this embodiment, the structure of the combustion device itself connected to the exhaust gas supply means 9 and the target to be combusted in the combustion device are not particularly limited. The combustion device may be a known device capable of burning a substance. The combustion device may be a new device installed for the treatment system of this embodiment, or an existing combustion device may be used in consideration of costs. Examples of the combustion device include a combustion device in a waste incineration facility, and a combustion device in a power generation facility that burns gas such as biogas. Furthermore, the substance to be combusted in the combustion device is not particularly limited as long as it contains at least one of a carbon component, a sulfur component, and a nitrogen component, and produces exhaust gas after combustion that contains components that exhibit acidity when dissolved in an aqueous solution, such as carbon dioxide, sulfur oxides, and nitrogen oxides.

[0185] An example of a combustion device is one that burns wastewater generated during the wastewater treatment process. This makes it possible to carry out electrode reactions in a series of wastewater treatment processes, as well as to carry out a process to suppress the decrease in electrode reaction efficiency. This improves the efficiency of energy recovery and utilization as well as reducing costs for the treatment system 1E. Specific examples of such combustion equipment include, for example, one that incinerates solids (sludge) separated in the solid-liquid separation section 3, and one that combusts gas (biogas) generated by anaerobic treatment in the treatment tank 2. This makes it possible to easily obtain the object to be burned, and to utilize existing combustion equipment for treating solids (sludge) discharged from the discharge pipe L4, utilizing biogas, etc. Furthermore, there is no need to install a new combustion equipment for the treatment system of the present invention, making it possible to significantly reduce initial costs. Furthermore, when sludge is used as the object to be burned, since the sludge contains a large amount of organic matter, exhaust gas containing a large amount of carbon dioxide is generated by the combustion process. In recent years, regulations on carbon dioxide emissions have become stricter in consideration of the impact on the environment. For this reason, by supplying exhaust gas containing carbon dioxide to the power generation unit 4, it is possible to suppress a decrease in the electrode reaction efficiency in the power generation unit 4, and since the carbon dioxide dissolves in the electrolyte solution in the power generation unit 4, it is also possible to suppress the emission of carbon dioxide to the outside of the system. The number of combustion devices is not limited to one, and multiple devices may be combined. For example, a device for incinerating solid matter and a device for burning gas may be combined. This allows for a stable supply of exhaust gas to the exhaust gas supply means 9, and enables the treatment of exhaust gas discharged from each combustion device to be performed at low cost.

[0186] As another aspect of the exhaust gas supply means 9 of this embodiment, it may be provided with a mechanism for adjusting the temperature of the exhaust gas. It is known that the temperature of exhaust gas generated in a combustion device can exceed 100 degrees. Meanwhile, the power generation unit 4 of the treatment system 1E in this embodiment performs an electrochemical reaction using electrodes placed in an aqueous solution, and if exhaust gas exceeding 100 degrees is directly supplied, it may accelerate the deterioration of the electrodes and cause problems due to heat, such as a decrease in the efficiency of the electrode reaction due to the evaporation (vaporization) of the electrolyte solution in the power generation unit 4. Therefore, it is preferable to adjust the temperature of the exhaust gas and supply it to the power generation unit 4.

[0187] FIG. 21 is a schematic explanatory diagram when a mechanism for adjusting the temperature of exhaust gas is provided as the exhaust gas supply means 9 in this embodiment. 21, an example of a mechanism for adjusting the temperature of the exhaust gas is to provide a temperature adjustment mechanism 93 on a pipe 92 and adjust the temperature of the exhaust gas. More specifically, the temperature adjustment mechanism 93 can cool the temperature of the exhaust gas to 100 degrees or less. This makes it possible to prevent malfunctions caused by heat when the exhaust gas is supplied into the power generation section 4 (second cell 41b).

[0188] The temperature adjustment mechanism 93 may be any known structure capable of adjusting the temperature of the gas (exhaust gas). One example of the temperature adjustment mechanism 93 is a heat exchanger using a gas such as air or a liquid such as cooling water. Another example of the temperature adjustment mechanism 93 is arranging exhaust gas piping and the like so that the treatment equipment such as the treatment tank 2 in the treatment system 1E of this embodiment can be heated using exhaust gas. In this way, the exhaust gas cooled after heating the treatment equipment such as the treatment 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 in the treatment system 1E as a whole.

[0189] As described above, in the treatment system 1E of this embodiment, by providing an exhaust gas supply means for supplying the exhaust gas generated in the combustion device to the power generation unit, it is possible to suppress an increase in pH on the cathode side in the electrode reaction, thereby suppressing a decrease in the efficiency of the electrode reaction and improving the efficiency of power generation and desulfurization treatment.

[0190] Moreover, in the treatment system 1E of this embodiment, it is possible to generate electricity and perform desulfurization treatment through the same steps as in the first embodiment.

[0191] [Sixth embodiment] Fig. 22 is a schematic explanatory diagram showing a processing system according to the sixth embodiment of the present invention, and Figs. 23 and 24 are schematic explanatory diagrams showing other aspects of the processing system according to the sixth embodiment of the present invention. As shown in Figs. 22 to 24, a treatment system 1F according to a sixth embodiment is the treatment system 1A according to the first embodiment, except that it is provided with a degassing means 10 for degassing gas contained in the electrodes 41a, 41b of the power generation section 4. Note that explanations of the same components as those in the first embodiment will be omitted. Figs. 22 to 24 are enlarged explanatory views of the periphery of the power generation section 4 of the treatment system 1F, and components related to the treatment tank 2 and solid-liquid separation section 3 are omitted.

[0192] The electrode 43a in this embodiment directly collects electrons from the reducing substance in the filtrate F. Therefore, by improving the contact efficiency between the electrode 43a and the reducing substance, the reaction efficiency as an electron donor (the electron collection rate at the electrode 43a) is improved, and it becomes possible to improve the power generation efficiency. Similarly, in the electrode 43b, by improving the contact efficiency between the electrode 43b and the electron acceptor, it becomes possible to improve the power generation efficiency.

[0193] On the other hand, when a porous body with a large specific surface area is used as the electrode 43a or the electrode 43b in consideration of power generation efficiency, a space into which gas can enter is present inside the electrode. Therefore, if the electrodes 43a and 43b made of a porous body are directly placed in the cells (first cell 41a and second cell 41b) that store liquid such as treated water, air bubbles will be present inside the electrodes 43a and 43b, and the contact area between the surfaces of the electrodes 43a and 43b and liquid such as the filtrate F will decrease. In this case, a problem occurs in that the efficiency of the electrode reaction by the reducing substance or the electron acceptor decreases in the electrodes 43a and 43b.

[0194] (Degassing means) The degassing means 10 is for removing gas contained in the electrodes 43a and 43b in the power generation section 4, and suppressing a decrease in the electrode reaction efficiency. The degassing means 10 is not particularly limited as long as it can remove the gas contained in the electrodes 43a and 43b. In addition, the degassing means 10 in this embodiment may be one that performs degassing while the electrodes 43a and 43b are installed in the power generation unit 4, or one that performs degassing of the 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 the electrodes 43a and 43b in the power generation unit 4, the electrodes 43a and 43b can be transported and installed as usual, and the degassing process can be easily performed 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 the electrodes 43a and 43b outside the power generation unit 4, multiple electrodes can be treated at once without adding any equipment related to degassing to the power generation unit 4, and the operating cost can be reduced. Therefore, the degassing means 10 may be located either inside or outside the power generation section 4, and can be appropriately selected in consideration of the degassing effect, working efficiency, and the like.

[0195] The degassing means 10 in this embodiment includes a means for adding a drug 10A for adding a drug to the electrodes. The chemical addition means 10A may be any means capable of removing gas contained in the electrodes by adding a chemical, such as a means for adding a chemical to the electrodes 43a and 43b outside the power generation unit 4, or a means for adding a chemical inside the power generation unit 4. By using the chemical addition means 10A as the degassing means 10, the electrodes can be degassed by the relatively simple means of adding a chemical. In this case, it is possible to prevent the ancillary equipment related to the degassing of the electrodes from becoming large, and to reduce the initial cost.

[0196] A specific example of the chemical supplying means 10A is a mechanism for supplying chemicals to the electrodes 43a and 43b disposed in the power generating unit 4. FIG. 22 is a schematic explanatory diagram of a mechanism for adding a drug to the electrodes 43a and 43b in the power generation unit 4, as the drug addition means 10A of this embodiment. As shown in Fig. 22, the drug addition means 10A may be provided with drug supply ports 101a and 101b and drug supply means 102 in the first cell 41a and the second cell 41b, respectively, and arranged so that the drug comes into contact with the surfaces of the electrodes 43a and 43b. The dashed arrow in Fig. 22 indicates the inflow direction of the drug.

[0197] There is no particular limitation on the drug supply means 102 as long as it can add a drug. For example, the drug supply means 102 may include a storage unit for storing the drug, a control unit for determining and adjusting the amount of drug to be added, and the like.

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

[0199] As shown in Fig. 22, the chemical addition means 10A is not limited to providing chemical supply ports 101a, 101b and a chemical supply means 102 to the power generation unit 4. For example, the chemical supply means 102 may be connected to the inlet pipe L3, and the chemical may be supplied from the inlet 42a to the electrode 43a. This eliminates the need to provide a separate chemical supply port 101a, making it possible to simplify the device configuration.

[0200] Another embodiment of the drug addition means 10A is to provide equipment for adding a drug to the electrodes 43a, 43b outside the power generation unit 4, and after performing a degassing process all at once, to transport and place the electrodes 43a, 43b in a storage container filled with a storage solution to the power generation unit 4.

[0201] In this case, the preservation solution may be any liquid capable of preventing gas from flowing back into the electrodes 43a, 43b after the degassing process, and examples of such liquid include the chemical (solution) used in the degassing process, as well as pure water. It is preferable to use an aqueous solution such as pure water as the preservation solution. This allows the preservation solution to be easily replaced with the treatment water when the electrodes 43a, 43b are placed in the power generation unit 4, and even if the preservation solution flows out into the treatment water, it is possible to suppress the effect on the environmental conditions in the first cell 41a and the second cell 41b.

[0202] In this case, the storage container may be any container that can accommodate the electrodes 43a, 43b and the storage solution and prevent gas from flowing back into the electrodes 43a, 43b after the degassing process, and may be, for example, a box or bag made of a material that is neither breathable nor water-permeable. 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] When the degassing treatment using a chemical is performed outside the power generation unit 4 as the chemical addition means 10A, the chemical is not directly added to the power generation unit 4, so that there is less change in the environment within the first cell 41a and the second cell 41b, and the effect on the electrode reaction can be suppressed.

[0204] Another aspect of the degassing means 10 of this embodiment is one equipped with electrical processing means 10B for applying a voltage to the electrodes. The electrical treatment means 10B may be any means capable of applying a voltage to the electrodes while immersed in a solution such as the treatment water, and examples of such means include providing an electrochemical device that controls the voltage and current between the electrodes 43a and 43b disposed in the power generation unit 4, or providing equipment equipped with an electrochemical device that controls the voltage and current applied between the electrodes 43a and 43b outside the power generation unit 4. In particular, by providing the electrical treatment means 10B within the power generation unit 4 as the degassing means 10, the amount of newly added equipment configuration is reduced, and the equipment can be made smaller.

[0205] FIG. 23 is a schematic explanatory diagram when a voltage is applied between the electrodes 43a and 43b in the power generating section 4 as the electrical processing means 10B of this embodiment. As shown in FIG. 23, the electric processing means 10B may be provided with a voltage / current control device 103 connected to the electrodes 43a and 43b to perform electrochemical processing. More specifically, a voltage may be applied so that an electrode reaction in which gas is generated from the electrodes 43a and 43b proceeds. As a result, the gas contained in the electrodes 43a and 43b is pushed out of the electrodes 43a and 43b by the gas generated by the electrode reaction, so that the electrodes can be degassed. At this time, the electrode reaction in which gas is generated may be electrolysis of the aqueous solution (water) stored in the first cell 41a and the second cell 41b. Hydrogen and oxygen are generated by electrolysis of water in the power generation unit 4, and the hydrogen and oxygen are released to the outside of the electrodes 43a and 43b together with the gas contained in the electrodes 43a and 43b, so that the electrodes can be degassed. As a result, it is almost unnecessary to add new equipment as the degassing means 10, so that the equipment cost can be significantly reduced.

[0206] Another aspect of the degassing means 10 of this embodiment is one equipped with a decompression means 10C for applying a decompression treatment to the electrodes. The pressure reducing means 10C may be any means capable of performing a pressure reducing process on at least the electrodes and removing the gas contained in the electrodes as a result, and examples of such means include a means for reducing the pressure inside the cells (first cell 41a and / or second cell 41b) with the electrodes 43a and 43b disposed inside the power generating unit 4, and a means for performing a pressure reducing process on the electrodes 43a and 43b outside the power generating unit 4 and then storing them in a storage container while maintaining the reduced pressure state. By using the pressure reducing means 10C as the degassing means 10, the electrodes can be degassed without changing the environmental conditions (pH, concentrations of various compounds, etc.) inside the first cell 41a and the second cell 41b.

[0207] FIG. 24 is a schematic explanatory diagram of the pressure reduction means 10C of this embodiment, which reduces the pressure inside the first cell 41a and the second cell 41b with the electrodes 43a and 43b arranged in the power generation section 4. As shown in FIG. 24, the pressure reducing means 10C may include flow rate adjustment valves 104a to 104d and a pressure reducing device 105. An example of the pressure reducing means 10C of this embodiment will be described with reference to FIG. 24. In the pressure reducing means 10C shown in FIG. 24, flow rate control valves 104a and 104b are provided on the inlet pipe L3 and the outlet pipe L5 for introducing and discharging the filtrate F to the first cell 41a, and flow rate control valves 104c and 104d are provided on the pipes 106 and 107 connected to the electron acceptor supply port 44a and the electron acceptor outlet port 44b for introducing and discharging the electron acceptor to the second cell 41b. This makes it possible to partition the first cell 41a and the second cell 41 from other equipment (such as the treatment tank 2 and the solid-liquid separation section 3) related to the treatment system 1F by opening and closing the flow rate control valves 104a to 104d. In order to reduce the pressure in the partitioned space, the pressure reducing means 10C shown in FIG. 24 is provided with a pressure reducing device 105 connected to the first cell 41a and the second cell 41b. Thus, the pressure in the first cell 41a and the second cell 41b, which are partitioned spaces, is reduced by driving the pressure reducing device 105. At this time, the gas contained in the electrodes 43a and 43b is released to the outside of the 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 may be a device known as a pressure reducing pump.

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

[0210] In addition, when connecting the pressure reducing device 105 to the first cell 41a and the second cell 41b, a new pipe may be provided, or an existing pipe may be utilized. In particular, by utilizing an existing pipe, the device configuration can be simplified.

[0211] The degassing means 10 in the treatment system 1F of this embodiment is not limited to the above-mentioned chemical addition means 10A, electrical treatment means 10B, and pressure reduction means 10C, each of which is performed individually, but may be a combination of a plurality of the above-mentioned means 10A to 10C. This makes it possible to select and perform a suitable degassing means 10 depending on the shape and arrangement of the electrodes 43a and 43b, thereby obtaining a higher degassing effect.

[0212] The conditions for degassing the electrodes by the degassing means 10 in this embodiment (such as the number of times it is performed and the timing of degassing) are not particularly limited. For example, each degassing means 10 (means 10A to 10C) may be performed only once before or after the electrodes are installed in the power generation unit 4, or may be repeated multiple times. Note that the degassing efficiency can be increased by repeatedly performing the degassing means 10, but the number of times it is performed can be set appropriately in consideration of the costs (chemical costs, power costs, etc.) related to driving the degassing means 10. In addition, the timing for performing the degassing means 10 may include, for example, the timing when a new electrode is used, such as when replacing the electrode, as well as the timing after maintenance (cleaning, etc.) of the electrode.

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

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

[0215] Moreover, in the treatment system 1F of this embodiment, it is possible to generate electricity and perform desulfurization treatment by the same steps as in the first embodiment.

[0216] Furthermore, the electrode of this embodiment suppresses a decrease in the specific surface area inside the electrode, and when power generation is performed in a series of processes in wastewater treatment, the efficiency of power generation and electrochemical treatment can be improved. In particular, when power generation or desulfurization functions are added to an existing treatment system, the use of the electrode of this embodiment suppresses a decrease in the efficiency of the electrode reaction, and makes it possible to perform power generation and desulfurization with high efficiency.

[0217] [Seventh embodiment] Fig. 25 is a schematic explanatory diagram showing a processing system according to the seventh embodiment of the present invention, and Figs. 26 and 27 are schematic explanatory diagrams showing other aspects of the processing system according to the seventh embodiment of the present invention. As shown in Figs. 25 to 27, a treatment system 1G according to a seventh embodiment is the treatment system 1A according to the first embodiment, except that an insulating mechanism 11 is provided for insulating the treated water W2 discharged from the first cell 41a. Note that explanations of the same configurations as those of the first embodiment will be omitted. Also, Figs. 25 to 27 are enlarged explanatory views of the periphery of the power generation section 4 of the treatment system 1G, and the configurations related to the treatment tank 2 and solid-liquid separation section 3 are omitted from the illustration.

[0218] As described above, when an electrode reaction is carried out, it is preferable to insulate the area other than the area where the electrode reaction is carried out (power generation section 4). The treatment system 1G in this embodiment is provided 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 the electrodes 43a and 43b, improving the electrode reaction efficiency. As a result, the power generation efficiency and the desulfurization treatment efficiency can be improved. Note that the treatment system 1G in this embodiment may also be configured to insulate the structures (treatment tank and piping) constituting the treatment system as shown in the first embodiment. This provides a stronger insulating effect, making it possible to 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 the 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 eliminating means or liquid junction time shortening means include a means for making the flow of the treated water W2 discontinuous (intermittent), a means for interposing an insulator such as air in the treated water W2, or a combination of these means.

[0220] FIG. 25 is a schematic explanatory diagram showing the insulation mechanism 11 of the processing system 1G in this embodiment. As shown in FIG. 25, the insulation mechanism 11 in this embodiment includes a storage tank 111 and a water sprinkling means 112 for sprinkling the treatment 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 as long as it is a tank capable of storing the treated water W2. Since the air present in the storage tank 111 functions 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 state). This makes it possible to further enhance the insulating effect of the treated water W2.

[0222] The water sprinkling means 112 discharges the treated water W2 in the form of droplets. The air in the storage tank 111 acts as an insulator between the droplets of the treated water W2 discharged by the water sprinkling means 112, so that it is possible to eliminate liquid junctions or shorten the time for which liquid junctions exist. The water sprinkling means 112 is not particularly limited as long as it can make the treated water W2 into droplets. A specific example of the water sprinkling means 112 is, for example, a structure connected to the outlet of the discharge pipe L5 and having a plurality of holes like a shower head, as shown in Fig. 25. Another example of the water sprinkling means 112 is a flat-plate-shaped structure provided in the storage tank 111 facing the outlet of the discharge pipe L5 and spaced a predetermined distance from it.

[0223] FIG. 26 is a schematic explanatory diagram showing another example of the insulating mechanism 11 of the processing system 1G in this embodiment. As shown in FIG. 26, the insulation mechanism 11 in this embodiment includes a storage tank 113 and a water discharge means 114 that intermittently discharges the treated water W2 in 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 as long as it is a 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 in the storage tank 113. An example of the water discharge means 114 is a means for periodically opening and closing an electromagnetic valve 114a provided in a discharge pipe 115 for discharging the treated water W2 from the storage tank 113. This makes the flow of the treated water W2 discharged from the storage tank 113 through the discharge pipe 115 intermittent, thereby eliminating liquid junctions of the treated water W2 or shortening the time of liquid junctions.

[0225] FIG. 27 is a schematic explanatory diagram showing another example of the insulating mechanism 11 of the processing system 1G in this embodiment. As shown in FIG. 27, the insulation mechanism 11 in this embodiment is provided with a pipe diameter reduction means 116 for narrowing a portion of the pipe diameter of the exhaust pipe L5 on the exhaust pipe L5, and a gas supply means 117 for supplying gas into the exhaust pipe L5 from the upstream side of the pipe diameter reduction means 116.

[0226] The pipe diameter reducing means 116 is not particularly limited as long as it can partially narrow the pipe diameter of the discharge pipe L5. Examples of the pipe diameter reducing 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 the discharge pipe L5 from the outside. The gas supply means 117 is not particularly limited as long as it can supply gas from the upstream side of the pipe diameter reduction means 116 into the discharge pipe L5. An example of the gas supply means 117 is one that supplies air into the discharge pipe L5 using a pump or the like that applies pressure to air. Note that the gas supplied by the gas supply means 117 is not limited to air. For example, biogas generated in the treatment tank 2 or exhaust gas after biogas combustion may be used in addition to air.

[0227] By supplying gas (air) from the upstream side of the pipe diameter reduction means 116 using the gas supply means 117, only gas flows intermittently into the portion narrowed by the pipe diameter reduction means 116, making it possible to discontinuously flow the flow of the treated water W2 in the discharge pipe L5. This makes it possible to eliminate liquid junctions of the treated water W2 in the discharge pipe L5 or shorten the liquid junction time.

[0228] As described above, the treatment system 1G in this embodiment is provided with the insulating mechanism 11 that insulates the treated water W2, thereby making it possible to eliminate the liquid junction between the power generation unit 4 and the treated water W2 or to shorten the liquid junction time. This prevents the electrons generated in the power generation unit 4 from flowing to anywhere other than between the electrodes 43a and 43b, thereby preventing a decrease in the efficiency of the electrochemical reaction (electrode reaction), and improves the power generation efficiency and the desulfurization treatment efficiency.

[0229] Moreover, in the treatment system 1G of this embodiment, it is possible to generate electricity and perform desulfurization treatment through the same steps as in the first embodiment.

[0230] [Eighth embodiment] FIG. 28 is a schematic explanatory diagram showing a processing system according to the eighth embodiment of the present invention. 28, a treatment system 1H according to the eighth embodiment is configured by providing an aeration tank 12 for treating treated water W2 discharged from a discharge pipe L5 of the power generation section 4 in the treatment system 1A according to the first embodiment, and connecting the aeration tank 12 and an electron acceptor supply port 44a provided in the second cell 41b of the power generation section 4 via a connection pipe L8. Note that a description of the same configuration as that of the first embodiment will be omitted.

[0231] In the treatment system 1H of this embodiment, the treated water W2 in the aeration tank 12 is supplied to the power generation unit 4 and used as an electron acceptor in the power generation unit 4. Note that the treated water W2 other than that supplied to the power generation unit 4 through the connection pipe L8 is discharged outside the system.

[0232] The aeration tank 12 aerates the treatment water W2 introduced into the tank with an oxygen-containing gas (oxygen, air, etc.) using an aeration device 12a, 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 treatment water W2 in the aeration tank 12. For example, a device consisting of a combination of a blower and an aeration pipe is widely used in aeration treatment.

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

[0235] After being used as an electron acceptor in the power generation unit 4, the treated water W2 is discharged from the electron acceptor outlet 44b. At this time, if the discharged treated water W2 satisfies the water quality requirements for discharge into a river or the like, it can be discharged as is. The discharged treated water W2 may also be returned to the aeration tank 12 and aerated again. This makes it possible to more reliably control the water quality of the treated water W2 to be discharged outside the system.

[0236] The treated water W2 in the aeration tank in the treatment system of this embodiment may be used for the contact efficiency improving means 5 described above. For example, the contact efficiency improving means 5 may be the movement speed control means 6 shown in the third embodiment or the dissolving means 8B, which is 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 through the connection pipe L8. At this time, the treated water W2 functions as a fluid in the movement speed control means 6. As described later, the treated water W2 contains microorganisms, and the microorganisms in the treated water W2 function as a substitute for a chemical agent that dissolves sediments in the dissolving means 8B.

[0237] As shown in Equations 1 and 2, precipitated sulfur accumulates as sediments on the surface of the electrode 43a. Meanwhile, in the aeration tank 12, aerobic microorganisms exist that oxidize sulfur to sulfite ions 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, the cleaning means 8 may be such that the electrode 43a is removed from the power generation section 4 and immersed in the aeration tank 12. In this way, the power generation and desulfurization means using the reducing substances in the filtrate F can be combined into the electrode cleaning means 8, which can reduce incidental equipment for cleaning the electrodes and significantly reduce running costs.

[0239] In addition, in the treatment system 1H of this embodiment, the treated water W2 in the aeration tank 12 is introduced into the power generation unit 4, so that the surfaces of the electrodes 43a and 43b are in a state where deposits mainly consisting of microorganisms are likely to accumulate. Therefore, in addition to the dissolving means 8B described above, it is preferable to further include any one of the peeling means 8A, the dispersing means 8C, and the surrounding environment changing means 8D to peel off the microorganisms accumulated on the surfaces of the electrodes 43a and 43b. This makes it possible to improve the efficiency of cleaning the surfaces of the electrodes 43a and 43b.

[0240] As described above, the treatment system 1H in this embodiment can utilize the products produced in the treatment process carried out within the treatment system 1H as electron donors and electron acceptors in the power generation section 4, making it possible to reduce the running costs associated with power generation and desulfurization treatment.

[0241] Moreover, in the treatment system 1H of this embodiment, it is possible to generate electricity and perform desulfurization treatment by the same steps as in the first embodiment.

[0242] The above-described embodiments are examples of the treatment system, power generation apparatus, desulfurization treatment apparatus, power generation method, and desulfurization method. The treatment system, power generation apparatus, desulfurization treatment apparatus, power generation method, and desulfurization method according to the present invention are not limited to the above-described embodiments, and the treatment system, power generation apparatus, desulfurization treatment apparatus, power generation method, and desulfurization method according to the above-described embodiments may be modified within the scope of the gist of the claims.

[0243] For example, the treatment system of this embodiment may be provided with a combination of a plurality of components selected from one or more of the contact efficiency improving means (movement speed control means, concentration control means, and cleaning means), exhaust gas supply means, degassing means, insulation mechanism, and aeration tank described above, thereby making it possible to enhance the effect of improving the efficiency of the electrode reaction.

[0244] For example, the treatment system in this embodiment may include a plurality of power generation units (power generation devices), which allows electrode reactions to be performed at a plurality of locations by effectively utilizing the treatment in the treatment system, and also allows both the treatment efficiency of the filtrate and the electrode reaction efficiency to be improved.

[0245] Furthermore, for example, the treatment system in this embodiment may be configured such that the electrode 43b is provided in the aeration tank 12, and the aeration tank 12 functions as the second cell 41b of the power generation section 4. This allows the power generation section 4 and the aeration tank 12 to be integrated, making it possible to further reduce the size of the equipment.

[0246] Furthermore, for example, the treatment system in this embodiment may be provided with a means for preventing adhesion and accumulation of microorganisms on the electrodes 43a and 43b. Examples of such a means include coating the electrode surfaces with a material that prevents adhesion of microorganisms, or making the structure of the electrodes themselves shaped to make it difficult for microorganisms to adhere to them. This makes it possible to suppress inhibition of the electrode reaction at the electrodes 43a and 43b by microorganisms even when microorganisms flow into the first cell 41a and the second cell 41b of the power generation unit 4.

[0247] Furthermore, for example, the processing system in this embodiment may omit some of the structures to further simplify the device configuration. An example of an optional structure is the ion exchanger 45. This allows simplification of the power generation section 4 (power generation device / desulfurization treatment device) and facilitates maintenance work. Another example of a structure that can be omitted is the electron acceptor supply port 44a and the electron acceptor discharge port 44b in the second cell 41b. This allows the power generation unit 4 (power generation device / desulfurization treatment device) to be further simplified. In this case, one surface of the electrode 43b may be in contact with the filtrate F or the ion exchanger 45, and the other surface may be in direct contact with the outside air (air) as a whole. Furthermore, it is preferable to provide a breathable material that is easily replaced or washed on the surface of the electrode 43b on the outside air side. This makes it possible to prevent solid impurities such as dust from adhering 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 a material to be treated, and are particularly suitable for use in anaerobic treatment in which reducing substances are contained in the discharged material after the material to be treated is anaerobically treated.

[0249] By applying the power generation device of the present invention to an existing treatment system, it is possible to provide the treatment system and power generation method of the present invention without large-scale renewal of the entire treatment system. Furthermore, by applying the desulfurization treatment device of the present invention to an existing treatment system, it is possible to provide the treatment system and desulfurization method of the present invention without large-scale renewal of the entire treatment system. [Explanation of symbols]

[0250] 1A, 1B, 1C, 1D, 1E, 1F, 1G, 1H Treatment system, 2 Treatment tank, 3 Solid-liquid separation section, 4 Power generation section, 41a First cell, 41b Second cell, 42a Inlet, 42b Outlet, 43a, 43b Electrode, 44a Electron acceptor supply port, 44b Electron acceptor outlet, 45 Ion exchanger, 46 Storage section, 47 Circulation flow path, 5 Contact efficiency improvement means, 6 Movement 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 adding means, 73 adsorbent, 74 pH control means, 75 storage section, 76 adding section, 77 pH detection section, 8 cleaning 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 section, 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 treatment means, 10C pressure reducing 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 water spray means, 114 water discharge means, 114a solenoid valve, 115 water discharge pipe, 116 pipe diameter reduction means, 117 gas supply means, 12 aeration tank, 12a aeration device, L1, L3 introduction pipe, L2, L6, L8 connection pipe, L4, L5, L7 discharge pipe, F filtrate, S treated material, W1 treated liquid, W2 treated water

Claims

1. A treatment system equipped with a digestion facility that performs anaerobic treatment on a material to be treated, A treatment system which generates electricity through a reaction in which reducing substances in the filtrate obtained by solid-liquid separation of effluent after anaerobic treatment act as electron donors.

2. A treatment system equipped with a digestion facility that performs anaerobic treatment on a material to be treated, A treatment system which performs desulfurization by a reaction in which reducing substances in the filtrate obtained by solid-liquid separation of effluent from anaerobic treatment act as electron donors.

3. 3. The treatment system according to claim 1, further comprising a power generation unit that generates electricity by contacting the filtrate with an electrode.

4. 4. The treatment system of claim 3, further comprising an ion exchanger disposed between said electrodes.

5. 5. The treatment system according to claim 3, further comprising a contact efficiency improving means for improving contact efficiency between an electrode surface of the power generation unit and electrode reaction components including reducing substances in the filtrate.

6. 6. The processing system according to claim 5, wherein the contact efficiency improving means comprises a moving speed control means for increasing a moving speed of the electrode reaction component relative to the electrode surface.

7. 7. The processing system according to claim 6, wherein the transport rate control means comprises a temperature control means for a reaction in which a reducing substance in the filtrate serves as an electron donor.

8. 6. The treatment system according to claim 5, wherein the contact efficiency improving means comprises a concentration control means for controlling the concentration of the electrode reaction component.

9. 9. The treatment system according to claim 8, further comprising a pH control means for dissolving the reducing substance in the filtrate in the filtrate, as the concentration control means.

10. 6. The processing system according to claim 5, wherein the contact efficiency improving means comprises a cleaning means for cleaning deposits deposited on the electrode surface.

11. 5. The treatment system according to claim 3, further comprising an exhaust gas supplying means for supplying the exhaust gas generated in the combustion device to the power generation section.

12. 12. The treatment system according to claim 11, wherein the combustion device incinerates solid matter obtained by solid-liquid separation of the effluent after anaerobic treatment and / or combusts gas produced by anaerobic treatment.

13. 5. The treatment system according to claim 3, further comprising a degassing means for removing gas contained in an electrode of the power generation section.

14. A power generation device to be installed in a treatment system for anaerobic treatment of a material to be treated, 1. A power generation device which generates power by using, as an electron donor, reducing substances in a filtrate obtained by solid-liquid separation of effluent after anaerobic treatment.

15. A desulfurization treatment device provided in a treatment system for anaerobic treatment of a material to be treated, 1. A desulfurization treatment apparatus, comprising: a filtrate obtained by solid-liquid separation of a discharged material after anaerobic treatment, and a reducing substance contained in the filtrate is used as an electron donor for desulfurization treatment.

16. A method for generating electricity in anaerobic treatment of a material to be treated, comprising the steps of:

1. A method for generating electricity, comprising the step of generating electricity by using, as an electron donor, reducing substances in a filtrate obtained by solid-liquid separation of effluent after anaerobic treatment.

17. A desulfurization method in anaerobic treatment of a material to be treated, comprising the steps of: A desulfurization method comprising a step of subjecting a reducing substance in a filtrate obtained by solid-liquid separation of an effluent after anaerobic treatment to a desulfurization treatment as an electron donor.

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