TW202005155A - Microbial power generation device using antimicrobial agent, and method for operating microbial power generation device - Google Patents

Abstract

A microbial power generation device having an anode chamber 4 which has an anode 6 and holds a fluid containing microbes and an electron donor, and also having a cathode chamber 3 which is separated from the anode chamber 4 by an ion-permeable non-conductive film 2 which is interposed therebetween, the microbial power generation device being configured so as to generate power by supplying an organic material-containing raw water to the anode chamber 4, and supplying a fluid containing an electron acceptor to the cathode chamber 3, wherein an antimicrobial agent is intermittently added to the anode chamber 4. In addition, the interior of the anode chamber 4 is intermittently aerated by using an inert gas from a diffuser tube 17.

Description

Microbial power generation device using bactericide and operation method of microbial power generation device

The present invention relates to a power generation device using a metabolic reaction of microorganisms and an operation method of a microbial power generation device. In particular, the present invention relates to a microbial power generation device and a method for operating a microbial power generation device that takes out reducing power as electrical energy, and the reducing power is obtained when microorganisms are oxidized to decompose organic matter.

As a power generation device using microorganisms, Patent Document 1 and Patent Document 2 describe that a cathode chamber and an anode chamber are divided by an electrolyte membrane.

Patent Document 1 describes that by adjusting the pH in the anode chamber to 7 to 9, the pH in the anode chamber caused by carbon dioxide gas generated by the reaction of microorganisms is prevented from decreasing, thereby improving power generation efficiency.

Patent Document 1: Japanese Patent Laid-Open No. 2009-152097 Patent Document 2: Japanese Patent Laid-Open No. 2000-133326

If the microbial power generating device is operated for a long time, the power generating microorganisms will multiply on the electrode surface. If the microorganisms are excessively attached to the electrode surface, the contact efficiency with the substrate or the conductivity of the electrode surface will decrease, and the power generation amount will decrease. In severe cases, the anode chamber is blocked and becomes unable to supply the substrate.

An object of the present invention is to provide a microbial power generation device and a microbial power generation method that suppress excessive adhesion of microorganisms in an anode chamber and can stably obtain a high power generation amount for a long period of time.

The microbial power generation device of the present invention includes an anode chamber having an anode and holding a liquid containing microorganisms and electron donors, and a cathode chamber separated from the anode chamber via a porous non-conductive membrane, and the anode The chamber supplies raw water containing organic substances, and supplies fluid containing electron acceptors to the cathode chamber to generate electricity. The microbial power generation device is characterized by including a sterilant supply unit that supplies the sterilant to the anode chamber.

In one aspect of the invention, the fungicide is hydrogen peroxide, hypochlorous acid or hypochlorite.

In one aspect of the present invention, there is a unit that supplies an inert gas to the anode chamber.

The method for operating a microbial power generation device of the present invention, wherein the microbial power generation device includes an anode chamber having an anode and holding a liquid containing microorganisms and electron donors, and is separated from the anode chamber via a porous non-conductive membrane The cathode chamber is opened, and raw water containing organic matter is supplied to the anode chamber, and a fluid containing an electron acceptor is supplied to the cathode chamber to generate electricity. The operation method of the microbial power generation device is characterized by intermittently feeding the anode chamber Fungicides are supplied sexually.

In one aspect of the present invention, the anode chamber is supplied with a sterilant for 1 minute to 1 hour at a frequency of 2 hours to 30 days.

In one aspect of the present invention, an inert gas is continuously or intermittently supplied to the anode chamber.

[Effect of invention] In the present invention, the sterilant is preferably supplied to the anode chamber intermittently. As a result, excessive adhesion of power-generating microorganisms to the surface of the anode is suppressed, and a high power generation amount can be stably maintained. Moreover, in the anode chamber under anaerobic conditions, in addition to power generating bacteria, methanogenic bacteria are also proliferated, which reduces the power generation efficiency. However, with the addition of intermittent fungicides, the growth rate is lower than that of the power generating bacteria’s methanogenic bacteria. The proliferation is further suppressed, so that the power generation efficiency can also be maintained high.

Hereinafter, the present invention will be described in more detail.

FIG. 1 is a schematic cross-sectional view showing a schematic configuration of a microbial power generation device according to an embodiment of the present invention.

The tank 1 is divided into a cathode chamber 3 and an anode chamber 4 by a partition material 2 including a porous non-conductive membrane. In the cathode chamber 3, a cathode 5 including a conductive porous material is arranged in close contact with the partition material 2. The cathode chamber 3 between the cathode 5 and the wall surface of the tank 1 is filled with the cathode solution. In order to aerate the cathode solution, a diffuser 7 is provided in the lower part of the cathode chamber 3. Oxygen-containing gas such as air is introduced into the diffuser 7, and aeration exhaust gas flows out from the gas outlet 8 in the upper part of the cathode chamber. In addition, as the aeration causes the evaporation or scattering of the cathode solution to decrease, the cathode solution for replenishment is appropriately supplied from the replenishment port 16 having the valve 15.

In the anode chamber 4, an anode 6 including a conductive porous material is arranged. The anode 6 is in close contact with the partition material 2 so that protons (H ⁺ ) can be donated from the anode 6 to the partition material 2.

Microbes are supported on the anode 6 including the porous material. For the anode chamber 4, the anode solution L is introduced from the inflow port 4a, and the waste liquid is discharged from the outflow port 4b. In addition, the inside of the anode chamber 4 is anaerobic.

The anode solution L in the anode chamber 4 circulates through the circulation outlet 9, the circulation pipe 10, the circulation pump 11, and the circulation return port 12. The circulation pipe 10 is provided with a pH meter 14 for measuring the pH of the liquid flowing out from the anode chamber 4, and a pipe 13 for adding a pH adjusting agent such as alkali or acid is connected. Furthermore, a pipe 19 for adding a sterilant is connected to the circulation pipe 10. In addition, the fungicide addition piping 19 may be directly connected to the anode chamber 4. Among them, by adding a bactericide to the circulating water, the sterilant can be supplied to the entire anode chamber 4 without omission.

The anode chamber 4 is provided with a diffuser tube 17, and thus, the valve chamber 17a is opened to aerate the anode chamber 4 with an inert gas such as nitrogen. A gas outlet 18 having a valve 18a is provided in the upper part of the anode chamber 4.

By supplying oxygen-containing gas such as air to the diffuser tube 7, the cathode solution in the cathode chamber 3 is aerated, and the pump 11 is operated as necessary to circulate the anode solution L, and then (organic matter) +H ₂ O→CO ₂ +H ⁺ +e ^- reaction. The electrons e ^- and 6 flows via the anode terminal 22, an external resistor 21, the cathode terminal 20 5.

The proton H ⁺ generated in the reaction moves to the cathode 5 through the partition 2. In the cathode 5, performed _{^{O 2 + 4H + + 4e -}} → 2H 2 O reaction. By this reaction, an electromotive force is generated between the cathode 5 and the anode 6, and the current flows to the external resistor 21 through the terminal 20 and the terminal 22.

A bactericide is preferably added to the anode chamber 4 intermittently. As a result, excessive adhesion of power-generating microorganisms to the surface of the anode is suppressed, and a high power generation amount can be stably maintained. Moreover, in the anode chamber under anaerobic conditions, in addition to power generating bacteria, methanogenic bacteria are also proliferated, which reduces the power generation efficiency. However, with the addition of intermittent fungicides, the growth rate is lower than that of the power generating bacteria’s methanogenic bacteria. The proliferation is further suppressed, so that the power generation efficiency can also be maintained high.

As the bactericide, the agent usually used as a slime control agent can be used, but in terms of cost or low residual effect on the post-processing, it is preferably hydrogen peroxide or hypochlorous acid Or its salt, hypobromous acid or its salt.

The frequency of addition of the bactericide to the anode chamber is from 2 hours to 30 days, preferably from 6 hours to 1 week, and the addition time per time is from 1 minute to 1 hour, preferably from 5 minutes ~30 minutes.

The concentration of the added water to the anode chamber also depends on the type of fungicide. If it is hydrogen peroxide, it is preferably 10 mg/L to 3,000 mg/L, more preferably 100 mg/L to 500 mg/L. For hypochlorous acid or hypochlorite, it is preferably 10 mg-3,000 mg-available chlorine/L, and more preferably 100 mg-500 mg-available chlorine/L.

In the anode chamber 4, the decomposition reaction of organic substances caused by microorganisms generates CO ₂ , and thus the pH changes. Therefore, alkali or acid is added to the anode solution L so that the detected pH of the pH meter 14 preferably becomes 7-9. The alkali or acid can be directly added to the anode chamber 4, but by adding to the circulating water, all areas in the anode chamber 4 can be maintained at pH 7 to pH 9 without local unevenness.

Then, the valve 17 a and the valve 18 a are opened continuously or intermittently, and the inside of the anode chamber 4 is aerated by the inert gas from the diffuser 7, and the exhaust gas flows out from the gas outlet 18. As a result, the surface of the anode 6 is given a shearing force generated by the gas, and the effect of suppressing the excessive adhesion of the biofilm is increased. In addition, especially when oxygen is used as an electron acceptor in the cathode chamber, etc. The effect of removing oxygen permeating from the cathode chamber to the anode chamber, which deteriorates performance due to the proliferation of aerobic slime, etc. As the inert gas, nitrogen is suitable, but it is not limited thereto.

2 is a schematic cross-sectional view of a microbial power generation device according to another embodiment of the present invention.

By arranging two plate-shaped partition materials 31 in parallel with each other in the substantially rectangular parallelepiped tank 30, an anode chamber 32 is formed between the partition materials 31 and the partition materials 31, respectively, and the anode chamber 32 Two cathode chambers 33 and 33 are formed via the partition material 31.

In the anode chamber 32, an anode 34 including a porous material is arranged in close contact with each partition 31. The anode 34 is gently crimped to the partition material (for example, at a pressure of 0.1 kg/cm ² or less).

In the cathode chamber 33, a cathode 35 including a porous material is arranged in contact with the partition material 31. The cathode 35 is pressed by a spacer 36 including rubber or the like, and is lightly pressed (for example, at a pressure of 0.1 kg/cm ² or less) to closely contact the partition material 31. In order to improve the adhesion between the cathode 35 and the partition material 31, the two may be welded, or locally adhered with an adhesive.

The cathode 35 and the anode 34 are connected to the external resistor 38 via the terminal 37 and the terminal 39.

The cathode chamber 33 between the cathode 35 and the side wall of the tank 30 is filled with the cathode solution. A diffuser tube 51 is provided in the lower part of each cathode chamber 33 to aerate the cathode solution. The aeration exhaust gas flows out from the gas outlet 52 in the upper part of the cathode chamber 33. Although not shown in the figure, a replenishment port is provided so as to replenish the cathode solution 33 to each cathode chamber 33.

For the anode chamber 32, the anode solution L is introduced from the inflow port 32a, and the waste liquid flows out from the outflow port 32b. The anode chamber 32 is anaerobic.

The anode solution in the anode chamber 32 circulates through the circulation outlet 41, the circulation piping 42, the circulation pump 43, and the circulation return port 44. A pipe 61 for adding sterilant is connected to the circulation pipe 42. In addition, a pH meter 47 is provided on the circulation pipe 42 and a pipe 45 for adding alkali is also connected. The pH of the anode solution flowing out from the anode chamber 32 is detected with a pH meter 47, and an alkali such as a sodium hydroxide aqueous solution is added so that the pH is preferably 7-9.

The anode chamber 32 is provided with a diffuser tube 57. By opening the valve 57 a, the anode chamber 32 is aerated with an inert gas. A gas outlet 58 having a valve 58a is provided in the upper part of the anode chamber 32.

In the microbial power generation device of FIG. 2, by supplying oxygen-containing gas to the diffuser 51, the cathode solution in the cathode chamber 33 is aerated, and the anode solution is circulated in the anode chamber 32, preferably the anode solution By circulation, a potential difference is generated between the cathode 35 and the anode 34, and the current flows to the external resistor 38.

The self-piping 61 preferably intermittently adds a bactericide, and at the same time intermittently opens the valve 57a and the valve 58a, aerates the inside of the anode chamber 32 with inert gas from the diffuser tube 57 and makes the exhaust gas flow from the gas outlet 58 Outflow.

In FIGS. 1 and 2, the diffuser is arranged in the cathode chamber 3 and the cathode chamber 33, and the cathode solution is aerated in the cathode chamber 3 and the cathode chamber 33. However, the cathode solution in the cathode chamber can also be introduced into Aeration in other aeration chambers.

Next, the microorganisms, anode solution, cathode solution, etc. of the microbial power generation device of the present invention, and suitable materials for the partition material, anode, and cathode will be described.

The microorganism that generates electric energy by being contained in the anode solution L is not particularly limited as long as it has a function as an electron donor. For example, Saccharomyces, Hansenula, Candida, Micrococcus, Staphylococcus, Streptococcus, Candida (Leuconostoa), Lactobacillus (Lactobacillus), Corynebacterium (Corynebacterium), Arthrobacter (Arthrobacter), Bacillus (Bacillus), Clostridium (Clostridium), Neisseria (Neisseria), Escherichia, Enterobacter, Serratia, Achromobacter, Alcaligenes, Flavobacterium, Acetobacter (Acetobacter), Moraxella, Nitrosomonas, Nitorobacter, Thiobacillus, Gluconobacter, Pseudomonas, Bacteria and filamentous fungi of each genus Xanthomonas, Vibrio, Comamonas, and Proteus (Proteus vulgaris) , Yeast, etc. Activated sludge obtained from biological treatment tanks containing organic matter-containing water such as self-treated sewage containing sludge of such microorganisms, microorganisms contained in effluent water from the initial sedimentation tank of sewage, and anaerobic digested sludge When it is supplied to the anode chamber as a seed, it can hold microorganisms in the anode. In order to improve power generation efficiency, the amount of microorganisms held in the anode chamber is preferably a high concentration, for example, the microorganism concentration is preferably 1 g/L to 50 g/L.

As the anode solution L, a solution that retains microorganisms or cells and has a composition required for power generation is used. For example, when generating electricity in the respiratory system, as the anode solution, breathing with a bouillon medium, M9 medium, L medium, malt extract (Malt Extract), MY medium, nitrifying bacteria selection medium, etc. can be performed A medium composed of energy sources or nutrients required for system metabolism. In addition, organic waste such as sewage, organic industrial drainage, and domestic garbage can be used.

In the anode solution L, in order to extract electrons from microorganisms or cells more easily, an electron mediator (Mediator) may be included. Examples of the electron mediator include compounds having a thiophene skeleton such as thiophene, dimethyldisulfonated thiophene, neomethylene blue, toluidine blue-O, 2-hydroxy-1,4-naphthoquinone, etc. Compounds with 2-hydroxy-1,4-naphthoquinone skeleton, Brilliant cresyl blue, Gallocyanine, Resorufin, Alizarine Brilliant Blue, Brown Phenothiazinone, phenazine ethosulfate, safranin-O, dichlorophenol indophenol, ferrocene, benzoquinone, phthalocyanine Or benzyl viologen (benzyl viologen) and derivatives of these.

Furthermore, if a material that increases the power generation function of the microorganism, such as an antioxidant such as vitamin C, or a function-enhancing material that only functions as a specific electron transfer system and substance transfer system in the microorganism is dissolved, it can be more It is better to obtain electricity efficiently.

The anode solution L may also contain a phosphate buffer as needed.

The anode solution L is a solution containing organic substances. The organic substance is not particularly limited as long as it is decomposed by microorganisms, and for example, water-soluble organic substances, organic substance fine particles dispersed in water, and the like are used. The anode solution can also be organic waste liquid such as sewage and food factory drainage. In order to improve power generation efficiency, the concentration of organic matter in the anode solution L is preferably a high concentration of about 100 mg/L to 10000 mg/L.

The temperature of the anode solution is preferably about 10°C to 70°C.

The cathode solution is neutral or alkaline, for example, preferably pH 6.0 to pH 9.0, and in order to maintain the pH within such a range, a buffer solution may be included.

Furthermore, the cathode solution may also contain redox reagents such as potassium ferricyanide, manganese sulfate, manganese chloride, ferric chloride, and ferric sulfate as electron acceptors. In this case, the concentration of the redox reagent in the cathode solution is preferably about 10 mM to 2,000 mM.

The cathode solution may also contain a chelating agent. By blending a chelating agent, tetravalent manganese can exist in a dissolved state, so that the effect of reducing the speed of the reduction reaction can be obtained.

As the chelating agent, as long as it can form a chelate compound with manganese ions, it can be used without limitation. Specifically, ethylenediaminetetraacetic acid (EDTA), 1,2-dihydroxyanthraquinone-3-yl-methylamino-N,N'-diacetic acid, 5,5'-dibromo-ortho Pyrogallol sulfophthalein (5,5'-Dibromo pyrogallol sulfophthalein), 1-(1-hydroxy-2-naphthylazo)-6-nitro-2-naphthol-4-sulfonic acid sodium salt, cyclic -Tri-[7-(1-azo-8-hydroxynaphthalene-3,6-disulfonic acid)] 6 sodium salt, 4-methylumbelliferone-8-methyleneiminodiacetic acid, 3 -Sulfo-2,6-dichloro-3',3''-dimethyl-4'-magentarone-5',5''-dicarboxylic acid 3 sodium salt, 3,3'-bis[ N,N-bis(carboxymethyl)aminomethyl]resinol sulfophthalein, sodium salt, 7-(1-naphthylazo)-8-hydroxyquinoline-5-sulfonic acid sodium salt, 4-( 2-pyridylazo) resorcinol, catechol sulfophthalein, 3,3'-bis[N,N-bis(carboxymethyl)aminomethyl]-o-cresol sulfophthalein, 2 sodium Salt etc. In addition, the chelating agent is ideally one that is not easily decomposed by biodegradation.

The oxygen-containing gas supplied to the cathode is preferably air. The exhaust gas from the cathode chamber can be ventilated to the anode chamber after being subjected to deoxygenation treatment as necessary, and used for the purge of dissolved oxygen from the anode solution L. As the supply amount of the oxygen-containing gas, it is sufficient that the DO can be detected when measuring the dissolved oxygen (DO) concentration of the cathode solution (for example, 0.5 mg/L or less).

As the partition material, paper including a porous non-conductive material, woven fabric, non-woven fabric, so-called organic membrane (precision filtration membrane), honeycomb-shaped molded body, lattice-shaped molded body, and the like can be used. As the partition material, in terms of ease of movement of protons, those made of a hydrophilic material, or preferably a precision filter membrane that hydrophilizes a hydrophobic membrane is used. When using a hydrophobic material, it should be processed into woven, non-woven, honeycomb and other shapes so that water can easily pass through. As the non-conductive material, specifically, polyethylene, polypropylene, polycarbonate, polyether sock (PES), polyvinylidene fluoride (PVDF), polytetrafluoroethylene (PTFE), polyethylene Alcohol (PVA), cellulose, cellulose acetate, etc. In order to allow protons to easily pass through, the partition material is preferably a thin material having a thickness of 10 μm to 10 mm, especially about 30 μm to 100 μm.

When organic waste water is used as the anode solution, in order to prevent clogging caused by suspended substances, it is preferable to use a material having a thickness of about 1 mm to 10 mm and excellent water permeability, such as a honeycomb or lattice material, as the area Partition. In the case where waste water is not used as the anode solution, as the partition material, in terms of thickness and price, paper with a thickness of 1 mm or less is most suitable. Moreover, since the thickness of the precision filter membrane made hydrophilic by PES and PVDF is extremely thin, it is suitable as a partition material when high output is required. Furthermore, in terms of cost, a non-woven fabric made of polyethylene or polypropylene is suitable.

The anode is preferably a porous body having a large surface area, a large number of voids, and water permeability so that a large number of microorganisms can be retained. Specifically, a porous conductive body (for example, graphite felt, foamed titanium, or the like) in which a sheet or a conductive material whose surface is roughened at least is made into a felt shape and other porous sheets is exemplified. Foamed stainless steel, etc.). When such a porous anode is in close contact with the partition material, the electrons generated by the microbial reaction are transferred to the anode without using an electronic medium, so that an electronic medium may not be required.

The anode is preferably a fibrous body including felt or the like. When the anode has a thickness greater than that of the anode chamber, the anode is compressed and inserted into the anode chamber, and is in close contact with the partition material by its own recovery elasticity.

A plurality of sheet-like conductive volume layers can also be made into anodes. In this case, the same kind of conductor sheets may be laminated, or different kinds of conductor sheets may be laminated with each other (for example, graphite felt and graphite sheet having a rough surface).

The overall thickness of the anode is 3 mm or more and 50 mm or less, particularly preferably about 5 mm to 40 mm. In the case where the anode is constituted by the laminated sheet, in order to cause the liquid to flow along the joining surface (the accumulated layer) of the sheets, it is preferable to align the laminated layer in the direction connecting the inflow port and the outflow port of the liquid.

The cathode is composed of a felt-like or porous conductive material, such as graphite felt, foamed stainless steel, or foamed titanium. In the case of a porous material, the diameter of the void is preferably about 0.01 mm to 1 mm. As the cathode, it is preferable to use those conductive materials that are formed into a shape (for example, a plate shape) that is easily in close contact with the partition material. When oxygen is used as the electron acceptor, it is preferable to use an oxygen reduction catalyst. For example, it is preferable to use graphite felt as a substrate to support the catalyst. Examples of the catalyst include noble metals such as platinum, metal oxides such as manganese dioxide, and carbon-based materials such as activated carbon. Depending on the type of electron acceptor, for example, when a liquid containing potassium hexacyanoferrate (III) acid (potassium ferricyanide) is used, an inexpensive graphite electrode can be used directly (without platinum loading) as the cathode. The thickness of the cathode is preferably 0.03 mm to 50 mm.

In addition, FIGS. 1 and 2 show a microbial power generation device that holds a cathode solution in a cathode chamber, but the present invention is not limited to such a microbial power generation device, and can also be applied to an air cathode that uses a cathode chamber as an empty chamber and circulates air Type microbial power plant. Examples

Hereinafter, comparative examples and examples will be described.

[Comparative Example 1] In the anode chamber of 7 cm×25 cm×1 cm (thickness), two pieces of graphite felt with a thickness of 1 cm were superimposed and filled to form an anode. With respect to this anode chamber, a cathode chamber was formed via a non-woven fabric with a thickness of 30 μm. The cathode chamber is also 7 cm×25 cm×1 cm (thickness), and two graphite felts with a thickness of 10 mm are stacked to form a cathode. On the graphite felts of the anode and the cathode, a conductive paste and a stainless steel wire were used as electrical lead wires, respectively, and connected with a resistance of 3 Ω.

Raw water containing 1,000 mg/L of acetic acid, 50 mM phosphate buffer and ammonium chloride was maintained in the anode chamber with a pH of 7.5. The raw water was pre-heated to 35°C in other water tanks and then passed into the anode chamber at 70 mL/min, thereby warming the temperature of the anode chamber to 35°C. In addition, before the raw water is passed through, the effluent of another microbial power generation device is passed through as a plant fungus. A cathode solution containing 50 mM potassium ferricyanide and phosphate buffer was supplied to the cathode chamber at a flow rate of 70 mL/min.

The power generation amount reaches 300 W/m ³ -anode chamber volume (hereinafter referred to as W/m ³ ) 1 week after the start of water supply, then evolves from 280 W/m ³ to 330 W/m ³ for the next 6 weeks, and then for 2 weeks Down to 100 W/m ³ . The device was disassembled and the anode was taken out. As a result, it was confirmed that a thick biofilm covered the inside of the graphite felt, and a water channel was formed in a part of the felt. It is believed that the attached biomass increases to cover the negative electrode, and the flow of water and the contact efficiency with the substrate have decreased.

[Example 1] The structure is the same as that of Comparative Example 1. One week after the start of water flow, when it reaches 300 W/m ³ , it is once every 12 hours, and the concentration added to the inflow water of the anode chamber becomes 100 mg/ Add hydrogen peroxide for 10 minutes. Immediately after the addition, the power generation capacity dropped significantly, but returned to its original value in about 30 minutes. After five months, the power generation capacity evolved from 280 W/m ³ to 330 W/m ³ . The device was disassembled and the negative electrode was taken out. As a result, compared with the comparative example, the adhesion amount of the biofilm was small, and the water flowed into the graphite felt.

[Example 2] The structure is the same as that of the comparative example, and nitrogen gas is ventilated into the anode chamber with an air volume of 200 mL/min. When 300 W/m ³ was reached one week after the start of water passing, once a day, hydrogen peroxide was added for 10 minutes so that the concentration added to the inflow water in the anode chamber became 100 mg/L. Immediately after the addition, the power generation capacity dropped significantly, but returned to its original value in about 30 minutes. After five months, the power generation capacity evolved from 280 W/m ³ to 330 W/m ³ . The device was disassembled and the negative electrode was taken out. As a result, compared with the comparative example, the adhesion amount of the biofilm was small, and the water flowed into the interior of the graphite felt.

[Example 3] The structure is the same as that of the comparative example. When 300 W/m ³ is reached within one week after the start of water passing, once a week, the concentration added to the inflow water of the anode chamber becomes 300 mg-available chlorine/L Add sodium hypochlorite for 30 minutes. Immediately after the addition, the power generation capacity dropped sharply, but it returned to its original value within 1 hour to 2 hours. After five months, the power generation capacity evolved from 280 W/m ³ to 330 W/m ³ . The device was disassembled and the negative electrode was taken out. As a result, compared with the comparative example, the adhesion amount of the biofilm was small, and the water flowed into the interior of the graphite felt.

According to the above comparative examples and examples, it was confirmed that, according to the present invention, excessive adhesion of microorganisms in the anode chamber to the anode surface in the microbial power generation device is suppressed, and a high power generation amount can be stably obtained for a long period of time.

Although the present invention has been described in detail using specific aspects, various changes can be made without departing from the intention and scope of the present invention, which is obvious to those having ordinary knowledge in the technical field to which they belong. This application is based on Japanese Patent Application 2018-054660 filed on March 22, 2018, and the entire contents are cited by reference.

1, 30‧‧‧ tank 2, 31‧‧‧ partition material 3. 33‧‧‧ Cathode chamber 4, 32‧‧‧Anode chamber 4a, 32a 4b, 32b‧‧‧ Outlet 5, 35‧‧‧ cathode 6, 34‧‧‧Anode 7, 17, 51, 57 8, 18, 52, 58‧‧‧‧ gas outlet 9.41‧‧‧Circulation export 10.42‧‧‧Circulation piping 11‧‧‧Circulation pump 12, 44 ‧‧‧ loop back 13‧‧‧Pipe for adding pH adjuster 14, 47‧‧‧ pH meter 15, 17a, 18a, 57a, 58a 16‧‧‧Supply port 19.61‧‧‧Pipe for adding fungicide 20, 22, 37, 39 21, 38‧‧‧External resistance 36‧‧‧ spacer 43‧‧‧Circulation pump 45‧‧‧Pipe for adding alkali

FIG. 1 is a schematic cross-sectional view of a microbial power generation device according to an embodiment of the present invention. Fig. 2 is a schematic cross-sectional view of a microbial power generation device according to another embodiment.

1‧‧‧Slot body

2‧‧‧Division material

3‧‧‧Cathode chamber

4‧‧‧Anode chamber

4a‧‧‧Flow inlet

4b‧‧‧Outflow

5‧‧‧Cathode

6‧‧‧Anode

7, 17‧‧‧ Diffuser

8, 18‧‧‧ gas outlet

9‧‧‧Circulation export

10‧‧‧Circulation piping

11‧‧‧Circulation pump

12‧‧‧return

13‧‧‧Pipe for adding pH adjuster

14‧‧‧pH meter

15, 17a, 18a‧‧‧ valve

16‧‧‧Supply port

19‧‧‧Pipe for adding fungicide

20, 22‧‧‧ Terminal

21‧‧‧External resistance

Claims (7)

A microbial power generation device includes an anode chamber having an anode and holding a liquid containing microorganisms and electron donors, and a cathode chamber separated from the anode chamber via a porous non-conductive membrane, and Raw water containing organic matter is supplied to the anode chamber, and fluid containing electron acceptors is supplied to the cathode chamber to generate electricity. The microbial power generation device is characterized by including: The sterilant supply unit supplies the sterilant to the anode chamber. The microbial power generation device according to item 1 of the patent application scope, wherein the bactericide is hydrogen peroxide, hypochlorous acid, or hypochlorite. The microbial power generation device according to item 1 or 2 of the scope of the patent application has a unit for supplying an inert gas to the anode chamber. A method for operating a microbial power generation device, wherein the microbial power generation device includes an anode chamber having an anode and holding a liquid containing microorganisms and electron donors, and a chamber separated from the anode chamber via a porous non-conductive membrane Cathode compartment, and The anode chamber is supplied with raw water containing organic matter, and the cathode chamber is supplied with a fluid containing an electron acceptor to generate electricity. The operation method of the microbial power generation device is characterized in that: A bactericide is intermittently supplied into the anode chamber. The method for operating a microbial power generation device as described in item 4 of the patent application range, wherein the sterilizing agent is supplied to the anode chamber at a frequency of 2 hours to 30 days every time for 1 minute to 1 hour. The method for operating a microbial power generation device as described in item 4 or 5 of the patent application, wherein the bactericide is hydrogen peroxide, hypochlorous acid or hypochlorite. The method for operating a microbial power generation device according to any one of claims 4 to 6, wherein an inert gas is continuously or intermittently supplied to the anode chamber.

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