WO2017199475A1

WO2017199475A1 - Liquid processing unit and liquid processing device

Info

Publication number: WO2017199475A1
Application number: PCT/JP2017/003179
Authority: WO
Inventors: 亮釜井; 雄也鈴木; 直毅吉川; 矢口　充雄
Original assignee: パナソニックＩｐマネジメント株式会社
Priority date: 2016-05-17
Filing date: 2017-01-30
Publication date: 2017-11-23

Abstract

A liquid processing unit (1) is provided with a liquid processing structure (40) having a first surface (40a) and a second surface (40b), and having a space between the first surface and the second surface in which hydrogen ions or hydroxide ions move. Furthermore, the liquid processing unit is provided with an oxygen concentration control unit (200) for mechanically controlling the concentration of oxygen supplied to the second surface. Moreover, the second surface is in contact with a hollow section (50) having a gas containing oxygen, and the oxygen concentration control unit is installed in the hollow section. A liquid processing device (100) is provided with the liquid processing unit, and a processing tank (80) for retaining the liquid processing unit and a liquid to be processed (90) therewithin.

Description

Liquid processing unit and liquid processing apparatus

The present invention relates to a liquid processing unit and a liquid processing apparatus. Specifically, the present invention relates to a liquid processing unit and a liquid processing apparatus for purifying waste water.

Conventionally, various water treatment methods have been provided in order to remove organic substances contained in wastewater. Specifically, water treatment methods such as an activated sludge method utilizing aerobic respiration of microorganisms and an anaerobic treatment method utilizing anaerobic respiration of microorganisms are provided.

In the activated sludge method, mud containing microorganisms (activated sludge) and wastewater are mixed in a biological reaction tank, and the air necessary for the microorganisms to oxidize and decompose organic matter in the wastewater is sent to the biological reaction tank and stirred. And the waste water is purified. However, the activated sludge method requires enormous electric power for aeration of the biological reaction tank. Moreover, as a result of microorganisms breathing oxygen and actively metabolizing, a large amount of sludge (a dead body of microorganisms), which is an industrial waste, is generated.

On the other hand, since the aerobic treatment method does not require aeration, the amount of electric power required can be greatly reduced compared to the activated sludge method. Moreover, since the free energy which microbes acquire is small, sludge generation amount reduces. As a liquid processing apparatus using such an anaerobic processing method, an apparatus in which an anaerobic microorganism is attached to a carrier using particles of a hydrogen storage alloy is disclosed (for example, see Patent Document 1).

However, the conventional anaerobic treatment method has a problem that a biogas containing a large amount of methane gas having a flammable characteristic odor is generated as a product of anaerobic breathing. Therefore, as a method for overcoming this, a method for suppressing the production of biogas by generating carbon dioxide as a metabolite by using an anaerobic microorganism that releases electrons to a conductive material by metabolism is disclosed. (For example, refer to Patent Document 2).

In addition to Patent Document 2, a microbial fuel cell is disclosed as a system for treating wastewater by using anaerobic microorganisms that release electrons by metabolism (for example, see Non-Patent Document 1). In Non-Patent Document 1, as an operation method for obtaining a high output in a microbial fuel cell, a high external resistance is connected at the start of startup, and after maintaining this to some extent, the external resistance is gradually increased as the output increases. Discloses a method of lowering to a certain value. According to this method, the anode potential is gradually increased by gradually reducing the external resistance, and as a result, an environment in which electrons can easily flow through the anode is prepared, so that the growth of microorganisms is promoted and more current can be obtained. It is thought that it will become.

JP-A-1-47494 International Publication No. 2014/174742

In a system capable of connecting an external resistance such as a microbial fuel cell, the anode potential can be controlled by gradually reducing the resistance value of the external circuit. However, for example, in a system using a local battery reaction as in Patent Document 2, it is difficult to connect an external resistor, and therefore the anode potential cannot be controlled. As a result, there has been a problem that the growth of microorganisms cannot be promoted through the control of the anode potential, and the metabolic rate due to the release of electrons from the microorganisms is reduced. Further, even in a system capable of connecting an external resistance such as a microbial fuel cell, there is a problem that changing the external resistance for each electrode each time is complicated both in terms of system and operation.

The present invention has been made in view of such problems of the conventional technology. An object of the present invention is to provide a liquid processing unit capable of suppressing the generation of biogas while reducing the amount of sludge generation and further improving the metabolic rate of microorganisms, and a liquid processing using the liquid processing unit. To provide an apparatus.

In order to solve the above problems, a liquid processing unit according to a first aspect of the present invention has a first surface and a second surface, and hydrogen ions are provided between the first surface and the second surface. Or the liquid processing structure which has the space where a hydroxide ion moves is provided. The liquid processing unit further includes an oxygen concentration control unit that mechanically controls the concentration of oxygen supplied to the second surface. And the 2nd surface is in contact with the space part which has the gas containing oxygen, and the oxygen concentration control part is attached to the space part.

A liquid processing apparatus according to a second aspect of the present invention includes the above-described liquid processing unit, a liquid processing unit, and a processing tank for holding the liquid to be processed therein.

FIG. 1 is a perspective view showing an example of a liquid processing apparatus according to the first embodiment of the present invention. FIG. 2 is a sectional view taken along line AA in FIG. FIG. 3 is an exploded perspective view showing a liquid processing unit in the liquid processing apparatus. FIG. 4 is a cross-sectional view showing another example of the liquid processing apparatus according to the first embodiment of the present invention. FIG. 5 is a cross-sectional view showing another example of the liquid processing apparatus according to the first embodiment of the present invention. FIG. 6 is a schematic diagram for explaining an oxygen concentration control unit in the liquid processing unit. FIG. 7 is a perspective view showing an example of a liquid processing apparatus according to the second embodiment of the present invention.

Hereinafter, the liquid processing unit and the liquid processing apparatus according to the present embodiment will be described in detail. In addition, the dimension ratio of drawing is exaggerated on account of description, and may differ from an actual ratio.

[First embodiment]
The liquid processing apparatus 100 according to the present embodiment includes a liquid processing unit 1 as shown in FIGS. 1 and 2. The liquid processing unit 1 includes a liquid processing structure 40 including the positive electrode 10, the negative electrode 20, and the ion conductive structure 30. In the liquid processing unit 1, the positive electrode 10 is disposed so as to be in contact with one surface 30 a of the ion conduction structure 30, and the negative electrode 20 is in contact with a surface 30 b opposite to the surface 30 a of the ion conduction structure 30. Is arranged. The gas diffusion layer 12 of the positive electrode 10 is in contact with the ionic conduction structural member 30 and the water repellent layer 11 is exposed to the space 50 side.

And as shown in FIG. 3, the liquid processing structure 40 is laminated | stacked on the cassette base material 60. As shown in FIG. The cassette base 60 is a U-shaped frame member along the outer peripheral portion of the surface 10a of the positive electrode 10, and the upper part is open. That is, the cassette base 60 is a frame member in which the bottom surfaces of the two first columnar members 61 are connected by the second columnar member 62. As shown in FIG. 2, the side surface 63 of the cassette base 60 is joined to the outer peripheral portion of the surface 10 a of the positive electrode 10, and the side surface 64 opposite to the side surface 63 is the outer periphery of the surface 70 a of the plate member 70. It is joined to the part.

As shown in FIG. 2, the liquid processing unit 1 formed by laminating the liquid processing structure 40, the cassette base material 60, and the plate member 70 is disposed inside the processing tank 80 so that the space 50 is formed. The A treatment liquid 90 that is waste water is held inside the treatment tank 80, and the positive electrode 10, the negative electrode 20, and the ion conductive structure 30 are immersed in the treatment liquid 90.

As will be described later, the positive electrode 10 includes a water repellent layer 11 having water repellency, and the plate member 70 is made of a flat plate material that does not transmit the liquid 90 to be processed. Therefore, the to-be-processed liquid 90 hold | maintained inside the process tank 80 and the inside of the cassette base material 60 are separated, and the internal space formed by the liquid processing structure 40, the cassette base material 60, and the plate member 70 is a space part. 50. In the space 50, the oxygen concentration control unit 200 mechanically controls the oxygen concentration inside.

(Positive electrode)
As shown in FIGS. 1 and 2, the positive electrode 10 according to the present embodiment includes a gas diffusion electrode including a water repellent layer 11 and a gas diffusion layer 12 stacked to be in contact with the water repellent layer 11. . By using such a thin plate-like gas diffusion electrode, oxygen in the space 50 can be easily supplied to the catalyst in the positive electrode 10.

The water repellent layer 11 in the positive electrode 10 is a layer having both water repellency and oxygen permeability. The water repellent layer 11 is configured to allow oxygen to move from the gas phase to the liquid phase while favorably separating the gas phase and the liquid phase in the electrochemical system in the liquid processing unit 1. That is, the water repellent layer 11 can suppress the movement of the liquid 90 to be processed toward the space 50 while passing the oxygen in the space 50 and moving it to the gas diffusion layer 12. In addition, "separation" here means physical interruption | blocking.

The water repellent layer 11 is in contact with the space portion 50 having a gas containing oxygen, and diffuses oxygen in the space portion 50. In the configuration shown in FIG. 2, the water repellent layer 11 supplies oxygen to the gas diffusion layer 12 substantially uniformly. Therefore, the water repellent layer 11 is preferably a porous body so that the oxygen can be diffused. In addition, since the water repellent layer 11 has water repellency, it can suppress that the pores of a porous body are obstruct | occluded by dew condensation etc. and oxygen diffusibility falls. In addition, since the liquid 90 to be treated does not easily penetrate into the water repellent layer 11, oxygen can be efficiently circulated from the surface in contact with the space 50 in the water repellent layer 11 to the surface facing the gas diffusion layer 12. It becomes possible.

The water repellent layer 11 is preferably formed in a sheet shape from a woven fabric or a non-woven fabric. The material constituting the water repellent layer 11 is not particularly limited as long as it has water repellency and can diffuse oxygen in the space 50. Examples of the material constituting the water repellent layer 11 include polyethylene, polypropylene, polybutadiene, nylon, polytetrafluoroethylene (PTFE), ethyl cellulose, poly-4-methylpentene-1, butyl rubber, and polydimethylsiloxane (PDMS). At least one selected from the group can be used. Since these materials are easy to form a porous body and also have high water repellency, they can suppress clogging of pores and improve gas diffusibility. The water repellent layer 11 preferably has a plurality of through holes in the stacking direction X of the water repellent layer 11 and the gas diffusion layer 12.

The water repellent layer 11 may be subjected to a water repellent treatment using a water repellent as necessary in order to enhance water repellency. Specifically, a water repellent such as polytetrafluoroethylene may be attached to the porous body constituting the water repellent layer 11 to improve water repellency.

The water repellent layer 11 may have a function of adjusting the amount of oxygen supplied from the space 50 to the gas diffusion layer 12. As a material of such a water repellent layer 11, for example, at least one of silicone rubber and polydimethylsiloxane can be used. Since these materials have high oxygen solubility and oxygen diffusibility derived from the molecular structure of silicone, they are excellent in oxygen permeability. Furthermore, since these materials have small surface free energy, they are excellent in water repellency. As the water repellent layer 11, Gore-Tex (registered trademark) formed by combining a film obtained by stretching polytetrafluoroethylene and a polyurethane polymer can be used.

The gas diffusion layer 12 in the positive electrode 10 preferably includes a porous conductive material and a catalyst supported on the conductive material. The gas diffusion layer 12 may be composed of a porous and conductive catalyst. By providing such a gas diffusion layer 12 in the positive electrode 10, electrons generated by a local battery reaction described later can be conducted between the negative electrode 20 and the catalyst. That is, as will be described later, a catalyst is supported on the gas diffusion layer 12, and the catalyst is an oxygen reduction catalyst. And when an electron moves to the catalyst through the gas diffusion layer 12 from the negative electrode 20, it becomes possible to advance the oxygen reduction reaction by oxygen, a hydrogen ion, and an electron with a catalyst.

In the positive electrode 10, in order to ensure stable performance, it is preferable that oxygen permeate the water-repellent layer 11 and the gas diffusion layer 12 efficiently and be supplied to the catalyst. Therefore, the gas diffusion layer 12 is preferably a porous body having a large number of pores through which oxygen passes from the surface facing the water repellent layer 11 to the opposite surface. The shape of the gas diffusion layer 12 is particularly preferably a three-dimensional mesh. Such a mesh shape makes it possible to impart high oxygen permeability and conductivity to the gas diffusion layer 12.

In the positive electrode 10, the water repellent layer 11 is preferably bonded to the gas diffusion layer 12 via an adhesive in order to efficiently supply oxygen to the gas diffusion layer 12. Thereby, the diffused oxygen is directly supplied to the gas diffusion layer 12, and the oxygen reduction reaction can be performed efficiently. The adhesive is preferably provided on at least a part between the water-repellent layer 11 and the gas diffusion layer 12 from the viewpoint of ensuring the adhesion between the water-repellent layer 11 and the gas diffusion layer 12. However, from the viewpoint of improving the adhesion between the water repellent layer 11 and the gas diffusion layer 12 and supplying oxygen to the gas diffusion layer 12 stably over a long period of time, the adhesive is used as the water repellent layer 11 and the gas diffusion layer. It is more preferable that it is provided on the entire surface between the two.

The adhesive preferably has oxygen permeability, and includes at least one selected from the group consisting of polymethyl methacrylate, methacrylic acid-styrene copolymer, styrene-butadiene rubber, butyl rubber, nitrile rubber, chloroprene rubber, and silicone. Resin can be used.

Here, the gas diffusion layer 12 of the positive electrode 10 in the present embodiment will be described in more detail. As described above, the gas diffusion layer 12 can be configured to include a porous conductive material and a catalyst supported on the conductive material.

The conductive material in the gas diffusion layer 12 can be composed of, for example, one or more materials selected from the group consisting of carbon-based substances, conductive polymers, semiconductors, and metals. Here, the carbon-based material means a material containing carbon as a constituent component. Examples of carbon-based materials include, for example, carbon powder such as graphite, activated carbon, carbon black, Vulcan (registered trademark) XC-72R, acetylene black, furnace black, Denka black, graphite felt, carbon wool, carbon woven cloth, etc. Carbon fiber, carbon plate, carbon paper, carbon disk, carbon cloth, carbon foil, and carbon-based material obtained by compression molding carbon particles are included. Examples of the carbon-based material also include fine-structured materials such as carbon nanotubes, carbon nanohorns, and carbon nanoclusters. Furthermore, as a conductive material in the gas diffusion layer 12, a metal material such as a mesh and a foam can also be used.

Conductive polymer is a general term for conductive polymer compounds. Examples of the conductive polymer include aniline, aminophenol, diaminophenol, pyrrole, thiophene, paraphenylene, fluorene, furan, acetylene, or a polymer of two or more monomers having a structural unit as a constituent unit. Can be mentioned. Specifically, examples of the conductive polymer include polyaniline, polyaminophenol, polydiaminophenol, polypyrrole, polythiophene, polyparaphenylene, polyfluorene, polyfuran, and polyacetylene. An example of the metal conductive material is a stainless mesh. In consideration of availability, cost, corrosion resistance, durability, and the like, the conductive material is preferably a carbon-based substance.

The shape of the conductive material is preferably a powder shape or a fiber shape. Further, the conductive material may be supported by a support. The support means a member that itself has rigidity and can give a certain shape to the gas diffusion electrode. The support may be an insulator or a conductor. When the support is an insulator, examples of the support include glass, plastic, synthetic rubber, ceramics, water-resistant or water-repellent treated paper, plant pieces such as wood pieces, bone pieces, animal pieces such as shells, and the like. . Examples of the porous structure support include porous ceramics, porous plastics, and sponges. When the support is a conductor, examples of the support include carbon materials such as carbon paper, carbon fiber, and carbon rod, metals, conductive polymers, and the like. When the support is a conductor, the support can also function as a current collector by disposing a conductive material carrying a carbon-based material on the surface of the support.

The catalyst in the gas diffusion layer 12 is a platinum-based catalyst, a carbon-based catalyst using iron or cobalt, a transition metal oxide-based catalyst such as partially oxidized tantalum carbonitride (TaCNO) and zirconium carbonitride (ZrCNO), tungsten Alternatively, a carbide catalyst using activated molybdenum, activated carbon, or the like can be used.

The catalyst in the gas diffusion layer 12 is preferably a carbon-based material doped with metal atoms. Although it does not specifically limit as a metal atom, Titanium, vanadium, chromium, manganese, iron, cobalt, nickel, copper, zirconium, niobium, molybdenum, ruthenium, rhodium, palladium, silver, hafnium, tantalum, tungsten, rhenium, osmium, iridium It is preferably an atom of at least one metal selected from the group consisting of platinum, and gold. In this case, the carbon-based material exhibits excellent performance as a catalyst for promoting the oxygen reduction reaction. What is necessary is just to set suitably the quantity of the metal atom which carbonaceous material contains so that carbonaceous material may have the outstanding catalyst performance.

It is preferable that the carbon-based material is further doped with one or more nonmetallic atoms selected from nitrogen, boron, sulfur, and phosphorus. What is necessary is just to set suitably the quantity of the nonmetallic atom doped by the carbonaceous material so that carbonaceous material may have the outstanding catalyst performance.

The carbon-based material is based on a carbon source material such as graphite and amorphous carbon, for example, and the carbon source material is doped with a metal atom and one or more non-metal atoms selected from nitrogen, boron, sulfur and phosphorus. Can be obtained.

The combination of metal atoms and nonmetal atoms doped in the carbon-based material is appropriately selected. In particular, it is preferable that the nonmetallic atom contains nitrogen and the metallic atom contains iron. In this case, the carbon-based material can have particularly excellent catalytic activity. Note that the nonmetallic atom may be only nitrogen, and the metallic atom may be only iron.

The nonmetallic atom may contain nitrogen, and the metallic atom may contain at least one of cobalt and manganese. Also in this case, the carbon-based material can have a particularly excellent catalytic activity. The nonmetallic atom may be only nitrogen. Further, the metal atom may be only cobalt, only manganese, or only cobalt and manganese.

The shape of the carbon-based material is not particularly limited. For example, the carbon-based material may have a particulate shape or may have a sheet shape. The dimension of the carbon-based material having a sheet-like shape is not particularly limited. For example, the carbon-based material may have a minute dimension. The carbon-based material having a sheet shape may be porous. It is preferable that the porous carbon-based material having a sheet shape has a shape such as a woven fabric shape or a nonwoven fabric shape. Such a carbon-based material can constitute the gas diffusion layer 12 even without a conductive material.

The carbon-based material configured as a catalyst in the gas diffusion layer 12 can be prepared as follows. First, for example, a mixture containing a nonmetallic compound containing at least one nonmetal selected from the group consisting of nitrogen, boron, sulfur, and phosphorus, a metal compound, and a carbon source material is prepared. And this mixture is heated at the temperature of 800 degreeC or more and 1000 degrees C or less for 45 second or more and less than 600 second. Thereby, the carbonaceous material comprised as a catalyst can be obtained.

Here, as the carbon source material, for example, graphite or amorphous carbon can be used as described above. Further, the metal compound is not particularly limited as long as it is a compound containing a metal atom capable of coordinating with a nonmetal atom doped in the carbon source material. Metal compounds include, for example, metal chlorides, nitrates, sulfates, bromides, iodides, fluorides, etc., inorganic metal salts, organic metal salts such as acetates, inorganic metal salt hydrates, and organic metal salts At least one selected from the group consisting of hydrates can be used. For example, when graphite is doped with iron, the metal compound preferably contains iron (III) chloride. Moreover, when graphite is doped with cobalt, the metal compound preferably contains cobalt chloride. When the carbon source material is doped with manganese, the metal compound preferably contains manganese acetate. The amount of the metal compound used is preferably determined so that, for example, the ratio of the metal atom in the metal compound to the carbon source material is in the range of 5 to 30% by mass, and further this ratio is 5 to 20% by mass. More preferably, it is determined to be within the range.

As described above, the nonmetallic compound is preferably at least one nonmetallic compound selected from the group consisting of nitrogen, boron, sulfur and phosphorus. Non-metallic compounds include, for example, pentaethylenehexamine, ethylenediamine, tetraethylenepentamine, triethylenetetramine, ethylenediamine, octylboronic acid, 1,2-bis (diethylphosphinoethane), triphenyl phosphite, benzyldisal At least one compound selected from the group consisting of fido can be used. The amount of the nonmetallic compound used is appropriately set according to the amount of the nonmetallic atom doped into the carbon source material. The amount of the nonmetallic compound used is preferably determined so that the molar ratio of the metal atom in the metal compound to the nonmetallic atom in the nonmetallic compound is in the range of 1: 1 to 1: 2. More preferably, it is determined to be within the range of 1: 1.5 to 1: 1.8.

A mixture containing a nonmetallic compound, a metal compound, and a carbon source material when preparing a carbon-based material configured as a catalyst is obtained, for example, as follows. First, a carbon source material, a metal compound, and a nonmetal compound are mixed, and if necessary, a solvent such as ethanol is added to adjust the total amount. These are further dispersed by an ultrasonic dispersion method. Subsequently, after heating them at an appropriate temperature (for example, 60 ° C.), the mixture is dried to remove the solvent. Thereby, the mixture containing a nonmetallic compound, a metal compound, and a carbon source raw material is obtained.

Next, the obtained mixture is heated, for example, under a reducing atmosphere or an inert gas atmosphere. Thereby, a non-metallic atom is doped to a carbon source raw material, and also a metallic atom is doped by the coordinate bond of a non-metallic atom and a metallic atom. The heating temperature is preferably in the range of 800 ° C. to 1000 ° C., and the heating time is preferably in the range of 45 seconds to less than 600 seconds. Since the heating time is short, the carbon-based material is efficiently produced, and the catalytic activity of the carbon-based material is further increased. In the heat treatment, the temperature rising rate of the mixture at the start of heating is preferably 50 ° C./s or more. Such rapid heating further improves the catalytic activity of the carbonaceous material.

In addition, the carbon-based material may be further acid cleaned. For example, the carbon-based material may be dispersed in pure water with a homogenizer for 30 minutes, and then the carbon-based material may be placed in 2M sulfuric acid and stirred at 80 ° C. for 3 hours. In this case, elution of the metal component from the carbon-based material can be suppressed.

By such a production method, a carbon-based material having a significantly low content of inert metal compound and metal crystal and high conductivity can be obtained.

In the gas diffusion layer 12, the catalyst may be bound to the conductive material using a binder. That is, the catalyst may be supported on the surface of the conductive material and inside the pores using a binder. Thereby, it can suppress that a catalyst detaches | leaves from an electroconductive material and an oxygen reduction characteristic falls. As the binder, for example, at least one selected from the group consisting of polytetrafluoroethylene, polyvinylidene fluoride (PVDF), and ethylene-propylene-diene copolymer (EPDM) is preferably used. Moreover, it is also preferable to use NAFION (registered trademark) as a binder.

(Negative electrode)
The negative electrode 20 in this embodiment has a function of supporting microorganisms to be described later and generating hydrogen ions and electrons from at least one of an organic substance and a nitrogen-containing compound in the liquid 90 to be treated by the catalytic action of the microorganisms. For this reason, the negative electrode 20 of the present embodiment is not particularly limited as long as it has such a function.

The negative electrode 20 of the present embodiment has a structure in which microorganisms are supported on a conductive sheet having conductivity. As the conductor sheet, it is possible to use at least one selected from the group consisting of a porous conductor sheet, a woven conductor sheet, and a nonwoven conductor sheet. The conductor sheet may be a laminate in which a plurality of sheets are laminated. By using such a sheet having a plurality of pores as the conductor sheet of the negative electrode 20, hydrogen ions generated in the local battery reaction described later easily move toward the positive electrode 10, and the rate of the oxygen reduction reaction is increased. It becomes possible to raise. From the viewpoint of improving ion permeability, the conductor sheet of the negative electrode 20 preferably has a space (void) continuous in the stacking direction X, that is, in the thickness direction.

The conductor sheet may be a metal plate having a plurality of through holes in the thickness direction. Therefore, the material constituting the conductor sheet of the negative electrode 20 is, for example, at least one selected from the group consisting of conductive metals such as aluminum, copper, stainless steel, nickel and titanium, and carbon paper, carbon felt, and graphite sheets. One can be used.

The microorganism supported on the negative electrode 20 is not particularly limited as long as it is a microorganism capable of decomposing organic compounds or nitrogen-containing compounds in the liquid 90 to be treated. For example, an anaerobic microorganism that does not require oxygen for growth is used. Is preferred. Anaerobic microorganisms do not require air for oxidizing and decomposing organic substances in the liquid 90 to be treated. Therefore, the electric power required for sending air can be significantly reduced. Moreover, since the free energy which microbes acquire is small, it becomes possible to reduce the amount of sludge generation.

The microorganism held in the negative electrode 20 is preferably an anaerobic microorganism, for example, an electricity producing bacterium having an extracellular electron transfer mechanism. Specifically, examples of the anaerobic microorganism include Geobacter genus bacteria, Shewanella genus bacteria, Aeromonas genus bacteria, Geothrix genus bacteria, and Saccharomyces genus bacteria.

Anaerobic microorganisms may be held on the negative electrode 20 by superimposing and fixing a biofilm containing anaerobic microorganisms on the negative electrode 20. For example, anaerobic microorganisms may be held on the surface 20b of the negative electrode 20 opposite to the surface 20a in contact with the ion conductive structure 30. The biofilm generally refers to a three-dimensional structure including a microbial population and an extracellular polymeric substance (EPS) produced by the microbial population. However, the anaerobic microorganisms may be held on the negative electrode 20 without depending on the biofilm. The anaerobic microorganisms may be held not only on the surface of the negative electrode 20 but also inside.

(Ion conduction structure)
The liquid processing unit 1 of the present embodiment further includes an ion conductive structure 30 that is provided between the positive electrode 10 and the negative electrode 20 and has permeability of hydrogen ions and hydroxide ions. As shown in FIGS. 1 and 2, the negative electrode 20 is separated from the positive electrode 10 via an ion conductive structure 30.

The ion conduction structure 30 has a function of transmitting hydrogen ions generated in the negative electrode 20 and moving the hydrogen ions to the positive electrode 10 side. In addition, the ionic conduction structural member 30 has a function of transmitting the hydroxide ions generated at the positive electrode 10 and moving it to the negative electrode 20 side. That is, the ion conduction structure 30 can move hydrogen ions and hydroxide ions through the inside thereof. Therefore, the hydrogen ions generated at the negative electrode 20 move inside the ion conductive structure 30 and react with the hydroxide ions generated at the positive electrode 10 to generate water. Alternatively, hydrogen ions generated at the negative electrode 20 are used for the oxygen reduction reaction at the positive electrode 10. Alternatively, hydroxide ions generated at the positive electrode 10 move inside the ion conductive structure 30 and react with hydrogen ions generated at the negative electrode 20 to generate water.

The ion conductive structure 30 is not particularly limited as long as it can conduct hydrogen ions and hydroxide ions without significantly inhibiting diffusion. Moreover, you may use the porous membrane which has the pore which can permeate | transmit a hydrogen ion and a hydroxide ion as the ion conduction structure 30. FIG. That is, the ion conductive structure 30 may be a sheet having a space (void) for the movement of hydrogen ions and hydroxide ions between the positive electrode 10 and the negative electrode 20. Therefore, it is preferable that the ionic conduction structural member 30 includes at least one selected from the group consisting of a porous sheet, a woven fabric sheet, and a nonwoven fabric sheet. The pore diameter of the ionic conduction structural member 30 is not particularly limited as long as hydrogen ions and hydroxide ions can move between the positive electrode 10 and the negative electrode 20.

The ion conductive structure 30 is preferably made of a conductor. That is, in the liquid processing unit 1, the gas diffusion layer 12 of the positive electrode 10 is disposed so as to contact one surface 30 a of the ion conduction structure 30, and the surface 30 b opposite to the surface 30 a of the ion conduction structure 30. It arrange | positions so that the negative electrode 20 may contact. Therefore, when the ionic conduction structural member 30 has conductivity, the positive electrode 10 and the negative electrode 20 are short-circuited. As a result, electrons generated at the negative electrode 20 move to the positive electrode 10, and an oxygen reduction reaction can be caused at the positive electrode 10.

The conductive ion conductive structure 30 is not particularly limited as long as it has a space in which hydrogen ions and hydroxide ions can move and is electrically connected from the negative electrode 20 toward the positive electrode 10. Further, the ionic conduction structural member 30 may extend continuously from the negative electrode 20 toward the positive electrode 10. Or the ion conduction structure 30 may be comprised from the several electrically-conductive part electrically connected. For example, the ion conductive structure 30 may have a configuration in which a plurality of conductive layers are stacked and electrically connected. When the electrical resistance between the positive electrode 10 and the negative electrode 20 in the ionic conduction structural member 30 is kept low, electrons generated by the decomposition of the organic matter easily move, and higher processing efficiency is obtained.

Furthermore, at least a part of the material constituting the ionic conduction structural member 30 may extend continuously from the negative electrode 20 toward the positive electrode 10, or may extend so as to cross the space. That is, at least a part of the material constituting the ion conduction structure 30 may extend in a direction perpendicular to the stacking direction X of the positive electrode 10, the negative electrode 20, and the ion conduction structure 30.

The material of the conductive ion conductive structure 30 is not particularly limited as long as the conductivity can be ensured. For example, at least one selected from the group consisting of a conductive metal, a carbon material, and a conductive polymer material can be used. As the conductive metal, for example, at least one selected from the group consisting of aluminum, copper, stainless steel, nickel, and titanium can be used. As the carbon material, for example, at least one selected from the group consisting of carbon paper, carbon felt, carbon cloth, and graphite foil can be used. Furthermore, as the conductive polymer material, at least one selected from the group consisting of polyacetylene, polythiophene, polyaniline, poly (p-phenylene vinylene), polypyrrole and poly (p-phenylene sulfide) can be used.

In addition, it is preferable that the ion conduction structure 30 is provided with at least one of a woven fabric-like conductor sheet and a nonwoven fabric-like conductor sheet. Since the woven fabric-like conductor sheet and the nonwoven fabric-like conductor sheet have a large number of pores, the movement of hydrogen ions and hydroxide ions can be facilitated. In addition, the ion conductive structure 30 may be a metal plate having a plurality of through holes from the negative electrode 20 to the positive electrode 10.

In addition, it is more preferable that the ion conductive structure 30 includes a non-woven conductor sheet, and it is particularly preferable that the ion conductive structure 30 is made of a non-woven conductor sheet. Since the nonwoven fabric easily changes its thickness and porosity, it is possible to easily improve the transmittance of hydrogen ions and hydroxide ions.

The ion conductive structure 30 may be made of an electrical insulator. However, in the liquid processing unit 1, the positive electrode 10 and the negative electrode 20 are electrically connected, and electrons generated by the negative electrode 20 need to move to the positive electrode 10. Therefore, when the ionic conduction structural member 30 is made of an electrical insulator, the positive electrode 10 and the negative electrode 20 may be electrically connected by an external resistance. Specifically, as shown in FIG. 4, the upper part of the positive electrode 10 and the negative electrode 20 may be connected by a conductive member 110. Further, as shown in FIG. 5, the positive electrode 10 and the negative electrode 20 may be connected by a conductive member 110 inside the ion conduction structure 30.

The conductive member 110 is not particularly limited as long as the positive electrode 10 and the negative electrode 20 can be electrically connected. For example, a metal material or a carbon material can be used. As the carbon material, for example, at least one selected from the group consisting of graphite foil, carbon paper, carbon cloth, and carbon felt can be used.

The electrically insulating ion conductive structure 30 is not particularly limited as long as it can conduct hydrogen ions and hydroxide ions without significantly inhibiting diffusion. Examples of the ion conductive structure 30 include a synthetic resin porous body, a glass fiber fabric, and a ceramic porous body. Examples of the synthetic resin porous material include polyolefin, polytetrafluoroethylene, polyvinylidene fluoride, nylon, polyurethane, acrylic resin, polyvinyl chloride, polystyrene, polyimide, phenol resin, epoxy resin, melamine resin, and urea resin. A nonwoven fabric containing at least one resin selected from the above can be mentioned. Moreover, as a porous body of a synthetic resin, a structure or a mesh containing the resin and having pores may be used. Among these, as the synthetic resin porous body, those that are not decomposed by the components of the liquid 90 to be treated are preferable.

When microorganisms come into contact with the positive electrode 10, solidified substances are adhered due to secretory components, excessive consumption of oxygen by the microorganisms, formation of a local pH gradient, and the like, and the amount of reaction accompanying electron transfer may decrease. There is. Therefore, it is preferable that the adhesion of microorganisms to the positive electrode 10 is inhibited as much as possible.

As a method for inhibiting the adhesion of microorganisms to the positive electrode 10, a method using an ion conductive structure 30 having a pore size that does not physically pass through microorganisms, or a method using chemical / biological action of the ion conductive structure 30. Is mentioned. Examples of the method utilizing chemical / biological action include a method of fixing a bactericide for sterilizing microorganisms to the ion conduction structure 30. As the bactericidal agent, for example, various antibiotics including a compound capable of releasing bactericidal silver ions and copper ions and tetracycline can be used. Moreover, the method by which ion conduction structure 30 itself has local pH which remove | deviates from the pH range which microorganisms can reproduce is mentioned.

In the liquid processing apparatus 100 according to the present embodiment, as shown in FIGS. 1 and 2, the surface 10 a of the positive electrode 10 of the liquid processing structure 40 is in contact with the space 50 having a gas containing oxygen. The liquid processing unit 1 includes an oxygen concentration control unit 200 that mechanically controls the concentration of oxygen supplied to the surface 10 a of the positive electrode 10, and the oxygen concentration control unit 200 is attached to the space 50. . Therefore, the space portion 50 can adjust the oxygen concentration by the oxygen concentration control unit 200.

Here, as described above, as an operation method for obtaining a high output in the microbial fuel cell, an electromotive force is generated with a high external resistance at the beginning of startup, and after maintaining this to some extent, an external force increases with an increase in output. It is preferable to gradually reduce the resistance to a certain value. Thus, by gradually lowering the external resistance, the anode potential increases stepwise, resulting in an environment in which electrons easily flow through the anode, and the growth of microorganisms is promoted.

In the present embodiment, since the oxygen concentration in the space 50 can be adjusted by the oxygen concentration control unit 200, the oxygen supply amount to the positive electrode 10 is also adjusted by adjusting the oxygen concentration, and the oxygen reduction reaction of the positive electrode 10 is performed. It becomes possible to control the reaction amount. Then, by adjusting the amount of oxygen supplied to the positive electrode 10, it is possible to control the reaction amount of the local battery reaction by the half reaction at each of the positive electrode 10 and the negative electrode 20. As a result, the reaction amount of microorganism metabolism accompanied by electron conduction in the negative electrode 20 can be controlled.

When starting the liquid processing apparatus 100 according to the present embodiment, the oxygen concentration control unit 200 in the liquid processing unit 1 is adjusted to reduce the oxygen concentration in the space 50 in the state of starting up. As a result, the amount of oxygen supplied to the positive electrode 10 is reduced, and the amount of oxygen reduction at the positive electrode 10 is reduced. When the amount of oxygen reduction at the positive electrode 10 decreases, the reaction amount of microorganism metabolism accompanied by electron conduction at the negative electrode 20 decreases accordingly. As a result, the potential at the negative electrode 20 becomes more negative.

Then, by adjusting the oxygen concentration control unit 200 and gradually increasing the oxygen concentration in the space 50, the amount of oxygen supplied to the positive electrode 10 increases and the amount of oxygen reduction at the positive electrode 10 increases. As the amount of oxygen reduction at the positive electrode 10 increases, the reaction amount of microorganism metabolism accompanied by electron conduction at the negative electrode 20 also increases, and the potential of the negative electrode 20 gradually becomes positive. As a result, the total amount of metabolism reaction of microorganisms accompanied by electron conduction is increased, and electric energy can be increased.

Thus, in the liquid processing unit 1 of the present embodiment, the anode potential is controlled by adjusting the amount of oxygen supplied to the positive electrode 10 using the oxygen concentration control unit 200. For this reason, it is possible to eliminate the need for the external resistance as compared with the control of the anode potential, which has been achieved by reducing the external resistance stepwise as in the prior art.

In the present embodiment, the configuration of the oxygen concentration control unit 200 is not particularly limited as long as the oxygen concentration in the space 50 can be controlled. The oxygen concentration control unit 200 can be configured as shown in FIG. 6, for example.

Specifically, as shown in FIG. 6A, the space area 50 in contact with the positive electrode 10 is a closed space other than the opening 51 communicating with the atmosphere, and the opening area of the opening 51 is changed. It can be set as a mechanism. In other words, the space 50 is provided with an opening 51 that communicates with the atmosphere, and the oxygen concentration control unit 200A includes a lid 201 that opens and closes the opening 51 and a lid control that controls opening and closing of the lid 201. Part 202. Then, the lid 201 is operated by the lid controller 202, the oxygen concentration in the space 50 is lowered by closing the opening 51, and oxygen in the atmosphere flows into the space 50 by opening the opening 51, It is possible to increase the oxygen concentration in the space 50. The lid control unit 202 may be configured to detect the oxygen concentration in the space 50 and open and close the lid 201 based on the oxygen concentration.

As shown in FIG. 6B, the oxygen concentration control unit 200 can be a mechanism that changes the air pressure in the space 50 in contact with the positive electrode 10. That is, the oxygen concentration control unit 200B connects the tank unit 211 in which a gas containing oxygen is stored, the tank unit 211 and the space unit 50, and supplies the gas in the tank unit 211 to the space unit 50; And a detector 213 for detecting the oxygen concentration in the space 50. Furthermore, the oxygen concentration control unit 200B includes a gas supply control unit 214 that controls the amount of gas supplied from the tank unit 211 by the supply unit 212 in accordance with the oxygen concentration detected by the detection unit 213.

In the oxygen concentration controller 200B, the oxygen concentration in the space 50 is first detected by the detector 213. When the detected oxygen concentration is high and it is necessary to reduce the oxygen concentration in the space 50, the gas supply control unit 214 controls the supply unit 212, and the gas supply from the tank unit 211 to the space 50 is performed. Reduce supply. As a result, the oxygen concentration in the space 50 can be reduced. On the other hand, when the detected oxygen concentration is low and the oxygen concentration in the space 50 needs to be increased, the gas supply control unit 214 controls the supply unit 212 so that the gas from the tank unit 211 to the space unit 50 is reduced. Increase supply. As a result, the oxygen concentration in the space 50 can be increased. The configuration of the supply unit 212 is not particularly limited, but may be a solenoid valve, for example. Also, the configuration of the detection unit 213 is not particularly limited, and for example, a commercially available oxygen concentration meter can be used.

Moreover, the oxygen concentration control unit 200 can be a mechanism that changes the flow rate of the gas from the opening provided in the space 50 as shown in FIG. That is, the oxygen concentration control unit 200 </ b> C can include a blower 221 that supplies a gas containing oxygen to the space 50. By using the blower 221, the flow rate of the gas supplied to the space 50 can be changed, and the oxygen concentration can be controlled.

It should be noted that the oxygen concentration control unit 200 may be configured to dilute the oxygen concentration in the space 50 with an inert gas such as nitrogen gas.

Next, regarding the liquid processing apparatus 100 of the present embodiment, the operation after the above-described startup will be described. During operation of the liquid processing apparatus 100, a liquid 90 to be processed containing at least one of an organic substance and a nitrogen-containing compound is supplied to the negative electrode 20, and air or oxygen is supplied to the positive electrode 10. At this time, air is continuously supplied through the oxygen concentration controller 200.

In the positive electrode 10 shown in FIGS. 1 and 2, air diffuses through the water repellent layer 11 and is diffused by the gas diffusion layer 12. In the negative electrode 20, hydrogen ions and electrons are generated from at least one of the organic substance and the nitrogen-containing compound in the liquid 90 to be treated by the catalytic action of microorganisms. The generated hydrogen ions pass through the space inside the ion conduction structure 30 by the liquid to be treated 90 and move to the positive electrode 10 side. Further, the generated electrons move to the ion conductive structure 30 through the conductive sheet of the negative electrode 20 and further move to the gas diffusion layer 12 of the positive electrode 10. Hydrogen ions and electrons are combined with oxygen by the action of the catalyst supported on the gas diffusion layer 12 and consumed as water.

For example, when the liquid 90 to be treated contains glucose as an organic substance, the above-described local battery reaction (half-cell reaction) is represented by the following formula.
Negative electrode 20: C ₆ H ₁₂ O ₆ + 6H ₂ O → 6CO ₂ + 24H ⁺ + 24e ⁻
・ Positive electrode 10: 6O ₂ + 24H ⁺ + 24e ⁻ → 12H ₂ O

Moreover, when the liquid 90 to be processed contains ammonia as a nitrogen-containing compound, the local battery reaction is expressed by the following formula.
Negative electrode 20: 4NH ₃ → 2N ₂ + 12H ⁺ + 12e ⁻
Positive electrode 10: 3O ₂ + 12H ⁺ + 12e ⁻ → 6H ₂ O

As described above, the organic substance and the nitrogen-containing compound in the liquid 90 to be processed can be decomposed by the catalytic action of microorganisms in the negative electrode 20 to purify the liquid 90 to be processed. In the positive electrode 10, hydroxide ions may be generated by a reduction reaction of oxygen. Therefore, the generated hydroxide ions may move inside the ion conduction structure 30 and combine with the hydrogen ions generated in the negative electrode 20 to generate water.

The liquid processing unit 1 according to this embodiment has a first surface 40a and a second surface 40b, and hydrogen ions or hydroxide ions move between the first surface 40a and the second surface 40b. A liquid processing structure 40 having a space to be used. Furthermore, the liquid processing unit 1 includes an oxygen concentration control unit 200 that mechanically controls the concentration of oxygen supplied to the second surface 40b. The second surface 40 b is in contact with the space 50 having a gas containing oxygen, and the oxygen concentration control unit 200 is attached to the space 50. With such a configuration, since the oxygen concentration in the space 50 can be arbitrarily controlled, the growth of microorganisms on the first surface 40a can be promoted, and a larger amount of current can be obtained. In the present embodiment, the first surface 40a of the liquid processing structure 40 corresponds to the surface 20b of the negative electrode 20 opposite to the surface 20a that contacts the ion conductive structure 30, and the second surface 40b is the positive electrode. This corresponds to the tenth surface 10a.

Moreover, the liquid processing apparatus 100 according to the present embodiment includes the liquid processing unit 1 and a processing tank 80 for holding the liquid processing unit 1 and the liquid to be processed 90 inside. As described above, the liquid processing apparatus 100 can efficiently oxidize and decompose components (organic substances or nitrogen-containing compounds) contained in the liquid 90 to be processed through an electron transfer reaction. Specifically, organic substances and / or nitrogen-containing compounds contained in the liquid 90 to be treated are decomposed and removed by anaerobic microorganism metabolism, that is, microorganism growth. And since this oxidative decomposition process is performed on anaerobic conditions, the conversion efficiency from an organic substance to the new cell of microorganisms can be suppressed low rather than the case where it is performed on an aerobic condition. For this reason, compared with the case where the activated sludge method is used, the proliferation of microorganisms, that is, the generation amount of sludge can be reduced. In addition, odorous methane gas is generated in a normal anaerobic process, but in the oxidative decomposition process in the present embodiment, the metabolite is, for example, carbon dioxide gas, and therefore the generation of methane gas can be suppressed.

Furthermore, in the liquid processing apparatus 100, by using the liquid processing unit 1 described above, the total reaction amount of metabolism of microorganisms accompanied by electron conduction can be increased, so that the purification performance of the liquid 90 to be processed can be further improved. It becomes possible.

Note that the processing tank 80 holds the liquid 90 to be processed therein, but may have a configuration in which the liquid 90 to be processed flows. For example, as shown in FIGS. 1 and 2, the treatment tank 80 has a wastewater supply port 81 for supplying the treatment liquid 90 to the treatment tank 80 and the treated liquid 90 after the treatment is discharged from the treatment tank 80. A waste water discharge port 82 may be provided. And it is preferable that the to-be-processed liquid 90 is continuously supplied through the waste-water supply port 81 and the waste-water discharge port 82. FIG.

The negative electrode 20 according to this embodiment may be modified with, for example, an electron transfer mediator molecule. Or the to-be-processed liquid 90 in the processing tank 80 may contain the electron transfer mediator molecule. Thereby, the electron transfer from an anaerobic microorganism to the negative electrode 20 is accelerated | stimulated, and more efficient liquid processing is realizable.

Specifically, in the metabolic mechanism by anaerobic microorganisms, electrons are transferred between cells or with the final electron acceptor. When a mediator molecule is introduced into the liquid 90 to be treated, the mediator molecule acts as a final electron acceptor for metabolism, and the received electrons are transferred to the negative electrode 20. As a result, it becomes possible to increase the rate of oxidative decomposition of the organic matter or the like in the negative electrode 20. The same effect can be obtained even if the mediator molecule is supported on the surface 20b of the negative electrode 20. Such an electron transfer mediator molecule is not particularly limited. As the electron transfer mediator molecule, for example, at least one selected from the group consisting of neutral red, anthraquinone-2,6-disulfonic acid (AQDS), thionine, potassium ferricyanide, and methylviologen can be used.

[Second Embodiment]
Next, the liquid processing unit and the liquid processing apparatus according to the second embodiment will be described in detail with reference to the drawings. In addition, the same code | symbol is attached | subjected to the same structure as 1st embodiment, and the overlapping description is abbreviate | omitted.

The liquid processing apparatus 100A according to the present embodiment includes a liquid processing unit 1A as shown in FIG. The liquid processing unit 1 </ b> A includes a liquid processing structure 40 </ b> A including the ion conductive structure 300 and the water repellent layer 11. In the liquid processing unit 1A, the water repellent layer 11 is disposed so as to contact one surface 300a of the ion conductive structure 300, and the water repellent layer 11 is exposed to the space 50 side.

The liquid processing structure 40A is laminated on the cassette base material 60. As shown in FIG. 7, the side surface 63 of the cassette substrate 60 is joined to the outer peripheral portion of the surface 11 a of the water repellent layer 11, and the side surface 64 opposite to the side surface 63 is the outer periphery of the surface 70 a of the plate member 70. It is joined to the part. The liquid processing unit 1A is arranged inside the processing tank 80 so that the space 50 is formed, and the ion conductive structure 300 is immersed in the liquid 90 to be processed. As in the first embodiment, the oxygen concentration control unit 200 mechanically controls the oxygen concentration inside the space 50.

In this embodiment, the liquid treatment structure 40A is composed of the ion conduction structure 300 and the water repellent layer 11. And the two electrodes are integrally formed by making the both ends of the ion conduction structure 300 function as two electrodes used for a battery reaction. Specifically, one surface 300a of the ionic conduction structural member 300 functions as a positive electrode, and the other surface 300b functions as a negative electrode. For this reason, since it is not necessary to provide the current collector used in the positive electrode 10 and the negative electrode 20 of the first embodiment, a simpler configuration can be realized.

As the ion conduction structure 300, the conductive ion conduction structure 30 in the first embodiment can be used. Further, the ionic conduction structural member 300 may carry an oxygen reduction catalyst on one surface 300a. As a result, the reaction between oxygen that has passed through the water-repellent layer 11 and hydrogen ions that have passed through the space inside the ion conduction structure 300 and moved to the one surface 300a side is promoted, and the reduction reaction efficiency of oxygen is increased. Therefore, more efficient liquid processing can be realized. As the oxygen reduction catalyst, the catalyst in the first embodiment can be used.

It is preferable to support anaerobic microorganisms on the other surface 300b functioning as the negative electrode in the ion conductive structure 300. Moreover, the anaerobic microorganisms may be hold | maintained at the surface 300b by superimposing the biofilm containing anaerobic microorganisms on the surface 300b, and fixing.

Next, the operation of the liquid processing apparatus 100A of this embodiment will be described. Similarly to the first embodiment, during the operation of the liquid processing apparatus 100A, a liquid 90 to be processed containing at least one of an organic substance and a nitrogen-containing compound is supplied to the surface 300b of the ion conductive structure 300, and the water repellent layer 11 is supplied with air or oxygen. At this time, air is continuously supplied through the oxygen concentration controller 200.

Then, oxygen passes through the water repellent layer 11 and reaches one surface 300a of the ion conductive structure 300. On the surface 300b of the ionic conduction structural member 300, hydrogen ions and electrons are generated from at least one of the organic substance and the nitrogen-containing compound in the liquid to be treated 90 by the catalytic action of microorganisms. The generated hydrogen ions pass through the inside of the ion conductive structure 300 by the liquid 90 to be processed and move to the surface 300a side. In addition, the generated electrons move to the surface 300 a through the ion conduction structure 300. Then, hydrogen ions and electrons are combined with oxygen by the action of the catalyst supported on the surface 300a and consumed as water.

Thus, also in the liquid processing apparatus 100A, the organic substance and the nitrogen-containing compound in the liquid 90 to be processed are decomposed by the catalytic action of the anaerobic microorganisms on the surface 300b of the ion conduction structure 300, and the liquid 90 to be processed is It becomes possible to purify. As in the first embodiment, hydroxide ions may be generated on the surface 300a of the ionic conduction structural member 300 due to a reduction reaction of oxygen. Therefore, the generated hydroxide ions may move inside the ion conduction structure 300 and combine with the hydrogen ions generated on the surface 300b to generate water.

Furthermore, also in the liquid processing unit 1A of the present embodiment, the anode potential can be controlled by adjusting the amount of oxygen supplied to the surface 300a of the ion conductive structure 300 using the oxygen concentration control unit 200. Therefore, by adjusting the oxygen concentration control unit 200 and gradually increasing the oxygen concentration in the space 50, it is possible to increase the metabolic reaction amount of the microorganisms supported on the surface 300b and increase the electrical energy. It becomes.

Although the present embodiment has been described above, the present embodiment is not limited to these, and various modifications are possible within the scope of the gist of the present embodiment. In addition, the liquid treatment apparatus according to the present embodiment can be widely applied to treatment of liquids containing organic substances and nitrogen-containing compounds, for example, wastewater generated from factories of various industries, organic wastewater such as sewage sludge, and the like. Furthermore, the liquid treatment apparatus can be used for improving the environment of the water area.

The entire contents of Japanese Patent Application No. 2016-098659 (filing date: May 17, 2016) are incorporated herein by reference.

According to the present invention, a liquid processing unit capable of suppressing the generation of biogas while reducing the amount of generated sludge and further improving the metabolic amount of microorganisms, and a liquid processing apparatus using the liquid processing unit are provided. Obtainable.

1, 1A Liquid treatment unit 40, 40A Liquid treatment structure 40a First surface 40b Second surface 50 Space 51 Opening 80 Treatment tank 90 Liquid to be treated 100, 100A Liquid treatment apparatus 200, 200A, 200B, 200C Oxygen Concentration control unit 201 Lid unit 202 Lid unit control unit 211 Tank unit 212 Supply unit 213 Detection unit 214 Gas supply control unit 221 Blower

Claims

A liquid treatment structure having a first surface and a second surface, and having a space in which hydrogen ions or hydroxide ions move between the first surface and the second surface;
An oxygen concentration controller that mechanically controls the concentration of oxygen supplied to the second surface;
With
The liquid processing unit, wherein the second surface is in contact with a space having a gas containing oxygen, and the oxygen concentration controller is attached to the space.
The space portion is provided with an opening communicating with the atmosphere,
The liquid processing unit according to claim 1, wherein the oxygen concentration control unit includes a lid that opens and closes the opening, and a lid controller that controls opening and closing of the lid.
The oxygen concentration controller is
A tank part in which the gas containing oxygen is stored;
A supply section for connecting the tank section and the space section and supplying gas in the tank section to the space section;
A detector for detecting the oxygen concentration in the space;
According to the oxygen concentration detected by the detection unit, a gas supply control unit that controls the supply amount of gas from the tank unit by the supply unit,
The liquid processing unit according to claim 1, comprising:
The liquid processing unit according to claim 1, wherein the oxygen concentration control unit has a blower for supplying a gas containing oxygen to the space.
A liquid processing unit according to any one of claims 1 to 4,
A treatment tank for holding the liquid treatment unit and the liquid to be treated therein;
A liquid processing apparatus comprising: