Fermentation apparatus and method for producing microbial carrier

Abstract

To provide a fermentation apparatus that is capable of efficiently fermenting organic matter in water to be treated, and a method for producing a microbial carrier used in the fermentation apparatus.SOLUTION: A fermentation apparatus 1 is configured to enable organic matter in water to be treated W to be fermented by microorganisms. The fermentation apparatus 1 includes a fermentation tank 2, a plurality of microbial carriers 3 that are disposed in the fermentation tank 2 and configured to support microorganisms, and a to-be-treated water spraying part 4 that sprays the water to be treated W onto the microbial carriers 3. Each microbial carrier 3 includes a polymer porous body 5 that is electrically conductive and provided with through-holes.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a fermentation apparatus and a method for producing a microbial carrier for use in a fermentation apparatus. [Background technology]

[0002] Conventionally, fermentation by microorganisms has been used for the purpose of removing organic matter from water to be treated that contains organic matter, recovering resources, etc. As a method for efficiently performing water treatment using microorganisms, the Down-flow Hanging Sponge (DHS) method is known, in which the water to be treated is sprayed onto a microbial carrier carrying sludge containing microorganisms, and the water to be treated is fermented by the microorganisms in the sludge while the water to be treated is permeated by gravity.

[0003] For example, Patent Document 1 describes a sprinkler-type purification device in which a treatment space is formed within a hollow tank, a sprinkler section is provided, and microbial carriers are filled and arranged below the sprinkler section. The device is equipped with a treated water supply means for supplying treated water from the sprinkler section to the microbial carriers, a treated water discharge means for extracting treated water purified by the microbial carriers, an air supply pipe for supplying oxygen-containing gas into the treatment space, and an exhaust pipe for discharging gas from within the treatment space. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] JP 2012-179517 A Summary of the Invention [Problem to be solved by the invention]

[0005] In fermentation devices using microorganisms, it is desirable to improve the fermentation efficiency in order to more efficiently remove organic matter from the water to be treated and recover resources. In recent years, it has been suggested that when microorganisms ferment organic matter, they may exchange electrons with other microorganisms. Therefore, by using a conductive porous body as a microbial carrier to facilitate the transfer of electrons between microorganisms, it is expected that the fermentation efficiency of organic matter can be further improved.

[0006] However, the conductive porous body has a lower porosity than conventional non-conductive porous bodies, and the water to be treated is less likely to permeate through it. Therefore, when the conductive porous body is used as a microbial carrier, the contact area between the water to be treated and the microbial carrier is reduced, which actually leads to a decrease in fermentation efficiency.

[0007] The present invention has been made in consideration of the above problems, and aims to provide a fermentation apparatus capable of efficiently fermenting organic matter in the water to be treated, and a method for producing a microbial carrier for use in this fermentation apparatus. [Means for solving the problem]

[0008] One aspect of the present invention is a fermentation apparatus configured to ferment organic matter in water to be treated by microorganisms, A fermentation tank; A plurality of microbial carriers arranged in the fermenter and configured to be capable of supporting the microorganisms; a water-to-be-treated spraying section for spraying the water to be treated onto the microorganism carrier; The microorganism carrier is in a fermentation apparatus and has a polymeric porous body that is electrically conductive and has through-holes.

[0009] Another aspect of the present invention is a method for producing a microbial carrier in a fermentation apparatus according to the above aspect, comprising the steps of: A conductive porous polymer body and a drilling tool having a rod-shaped insertion portion are prepared; The insertion portion is pressed into the polymeric porous body to form a through hole in the polymeric porous body; The present invention relates to a method for producing a microorganism carrier, which comprises producing a microorganism carrier using the above-mentioned polymeric porous material. Effect of the Invention

[0010] The fermentation apparatus has a microorganism carrier including a polymeric porous body having electrical conductivity and having through-holes. By providing the polymeric porous body with through-holes in this way, the water permeability of the microorganism carrier can be improved, and the water to be treated and the microorganisms can be in sufficient contact with each other. In addition, since the polymeric porous body is electrically conductive, electrons can be exchanged more easily between the microorganisms and other microorganisms when the microorganisms ferment organic matter.

[0011] Furthermore, by providing through holes in the conductive polymer porous body in this manner, the effect of improving water permeability due to the through holes and the effect of making it easier to exchange electrons act synergistically, thereby promoting the fermentation of organic matter by microorganisms.

[0012] In the method for producing the porous polymer body, first, through holes are formed in the porous polymer body having electrical conductivity. By using this porous polymer body, the microorganism carrier can be easily obtained.

[0013] As described above, according to the above-mentioned aspects, it is possible to provide a fermentation apparatus capable of efficiently fermenting organic matter in water to be treated, and a method for producing a microbial carrier used in this fermentation apparatus. [Brief description of the drawings]

[0014] [Figure 1] FIG. 1 is a cross-sectional view showing a main part of a fermentation apparatus in the first embodiment. [Diagram 2] FIG. 2 is a perspective view showing an example of the microorganism carrier in the first embodiment. [Diagram 3] FIG. 3 is a partial cross-sectional view showing another embodiment of the through-hole of the microorganism carrier. [Figure 4] FIG. 4 is an explanatory diagram of the method for producing the polymeric porous material in the first embodiment. [Diagram 5]FIG. 5 is a perspective view of a microorganism carrier having through-holes extending in different directions according to the second embodiment. [Figure 6] FIG. 6 is a cross-sectional view showing a main part of a fermentation apparatus equipped with electrodes in the third embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0015] (Embodiment 1) An embodiment of the fermentation apparatus will be described with reference to Figs. 1 to 4. The fermentation apparatus 1 of this embodiment is configured to ferment organic matter in the water to be treated W by microorganisms. As shown in Fig. 1, the fermentation apparatus 1 has a fermentation tank 2, a plurality of microorganism carriers 3 arranged in the fermentation tank 2 and configured to be able to support microorganisms, and a water to be treated spraying unit 4 that sprays the water to be treated W onto the microorganism carriers 3. The microorganism carriers 3 are conductive and have a polymer porous body 5 with through holes 51 as shown in Figs. 2 and 3. For convenience, the structure of the microorganism carriers 3 is simplified in Fig. 1.

[0016] The water to be treated W used in the fermentation apparatus 1 is not particularly limited, and any water to be treated W containing desired organic matter can be used. As the water to be treated W, for example, wastewater containing organic waste such as sewage sludge and food waste can be used. In addition, as the water to be treated W, for example, industrial wastewater containing organic matter such as waste water-soluble coolant recovered from a processing device that performs machining can also be used.

[0017] The shape and size of the fermenter 2 may take various forms. For example, the shape of the fermenter 2 in the fermentation apparatus 1 of this embodiment is cylindrical. The height and diameter of the fermenter 2 of this embodiment are both 2 m.

[0018] 1, a partition plate 21 configured to allow the flow of the water to be treated W is provided inside the fermenter 2. The internal space of the fermenter 2 is divided into two spaces: an upper space 22 located above the partition plate 21, and a lower space 23 located below the partition plate 21.

[0019] A microorganism carrier 3 and a water-to-be-treated spray unit 4 are disposed in the upper space 22 of the fermenter 2. The microorganism carrier 3 is placed on a partition plate 21 of the fermenter 2. The configuration of the microorganism carrier 3 will be described in more detail later.

[0020] The treated water spraying unit 4 is configured to be able to spray the treated water W to the microorganism carrier 3. The specific embodiment of the treated water spraying unit 4 is not particularly limited, and various embodiments can be taken. For example, the treated water spraying unit 4 may be arranged along the side surface in the upper space 22 of the fermenter 2, and may be configured to spray the treated water W to the microorganism carrier 3 from the side of the microorganism carrier 3. The treated water spraying unit 4 may be arranged above the microorganism carrier 3, and may be configured to spray the treated water W to the microorganism carrier 3 from above the microorganism carrier 3. From the viewpoint of more easily spraying the treated water W to the entire microorganism carrier 3 in the fermenter 2, it is preferable that the treated water spraying unit 4 is arranged above the microorganism carrier 3. As the treated water spraying unit 4, for example, a spray nozzle configured to be able to spray the treated water W in the fermenter 2, or a spray pipe having small holes for discharging the treated water W can be used.

[0021] The supply path of the water to be treated W from the outside of the fermentation apparatus 1 to the water to be treated spraying section 4 may take various forms. For example, the water to be treated spraying section 4 in this embodiment is configured to directly spray the water to be treated W supplied from the outside of the fermentation apparatus 1.

[0022] A gas outlet pipe 24 for leading gas generated by fermentation of the water to be treated W to the outside of the fermenter 2 may be provided in the upper space 22 of the fermenter 2. For example, the gas outlet pipe 24 in this embodiment is provided at the upper end of the fermenter 2.

[0023] A treated water outlet pipe 25 is provided in the lower space 23 of the fermenter 2 for leading the treated water W after it has been fermented by the microorganisms to the outside of the fermenter 2.

[0024] The microorganism carrier 3 has a conductive polymer porous body 5 having through-holes 51. The above-mentioned "conductive polymer porous body" refers to a porous body having a volume resistivity of 10 4 This refers to a polymeric porous material with a resistivity of Ω·m or less.

[0025] The microorganism carrier 3 may be composed of only the polymeric porous body 5, or may have a polymeric porous body 5 and a frame made of a plastic harder than the polymeric porous body 5 and attached to the outer surface of the polymeric porous body 5. As shown in Figs. 2 and 3, the microorganism carrier 3 of this embodiment is composed of only the polymeric porous body 5. A microorganism carrier 3 without a frame is more easily deformed than a microorganism carrier 3 with a frame. Therefore, by filling the fermenter 2 with the microorganism carrier 3 made of the polymeric porous body 5, the microorganism carrier 3 can be appropriately deformed in the fermenter 2, and the gaps between the microorganism carriers 3 can be made smaller. Therefore, by using the microorganism carrier 3 made of the polymeric porous body 5, the fermenter 2 can be filled with the microorganism carrier 3 more densely, and the fermentation efficiency of the water W to be treated can be further improved.

[0026] As the polymeric porous body 5, a foam molded body made of a conductive resin or a conductive elastomer can be used. More specifically, as the polymeric porous body 5, for example, a foam molded body of polyethylene to which conductivity has been imparted by a conductive filler, or a foam molded body of polyurethane to which conductivity has been imparted by a conductive filler can be used. When a foam molded body is used as the polymeric porous body 5, the bubbles contained in the foam molded body may be closed bubbles or open bubbles. In addition, the foam molded body may contain both closed bubbles and open bubbles.

[0027] The shape of the polymer porous body 5 is not particularly limited and may take various forms. For example, the shape of the polymer porous body 5 in this embodiment is a cube with one side measuring about 3 cm. From the viewpoint of increasing the amount of microorganisms that can be supported on the microorganism carrier 3, it is preferable that the polymer porous body 5 has a shape capable of encapsulating a sphere with a diameter of 1 cm.

[0028] From the viewpoint of increasing the packing property of the microorganism carrier 3 and increasing the amount of the microorganism carrier 3 packed in the fermenter 2, it is preferable that the polymeric porous body 5 has a shape that is enclosed in a sphere with a diameter of 10 cm. From the same viewpoint, it is preferable that the shape of the polymeric porous body 5 is either cylindrical, rectangular, or spherical. The above-mentioned "cylindrical" includes a geometrically defined cylinder, as well as a shape obtained by deforming a geometric cylinder to an extent that is generally recognized as a cylinder, such as a shape in which the side surface of the cylinder bulges outward. The above-mentioned "rectangular parallelepiped" includes a geometrically defined cube and rectangular parallelepiped, as well as a shape obtained by deforming a geometric rectangular parallelepiped to an extent that is generally recognized as a rectangular parallelepiped, such as a shape in which the side surface of the rectangular parallelepiped bulges outward. The above-mentioned "spherical" includes a geometrically defined sphere, as well as a shape obtained by deforming a geometric sphere to an extent that is generally recognized as a rectangular parallelepiped, such as a spheroid.

[0029] The aspect ratio of the polymeric porous bodies 5 is preferably within the range of 0.4 to 2.4. That is, it is preferable that the minimum aspect ratio of each polymeric porous body 5 is 0.4 or more and the maximum aspect ratio is 2.4 or less. In this case, the microbial carriers 3 can be packed more densely in the fermenter 2.

[0030] The aspect ratio of the porous polymer body 5 is calculated by the following method. First, the porous polymer body 5 is placed on a flat plate in the most stable state. For example, when the porous polymer body 5 is spherical, the porous polymer body 5 may be placed on the flat plate so that the projected area of ​​the porous polymer body 5 is the largest when projected from above onto the flat plate. When the porous polymer body 5 is cylindrical or rectangular, the porous polymer body 5 may be placed on the flat plate so that the flat surface having the largest area among the flat surfaces of the porous polymer body 5 contacts the flat plate. The distance from the flat plate to the upper end of the porous polymer body 5 in this manner placed on the flat plate is defined as the height of the porous polymer body 5.

[0031] Next, the porous polymer body 5 is observed from the side, i.e., from a direction perpendicular to the height direction, and the width of the porous polymer body 5 is measured. The ratio of the width to the height of the porous polymer body 5 thus obtained is defined as the aspect ratio.

[0032] The aspect ratio in each direction is calculated by repeating the above procedure while varying the observation direction of the polymeric porous body 5. The largest value among the aspect ratios thus obtained is taken as the maximum aspect ratio, and the smallest value is taken as the minimum aspect ratio.

[0033] The polymer porous body 5 has one or more through holes 51, as shown in FIG. 2, for example. Each through hole 51 has a first opening 511 provided on the surface of the polymer porous body 5, a second opening 512 provided at a position different from the first opening 511 on the surface of the polymer porous body 5, and an intra-hole space 513 connecting the first opening 511 and the second opening 512. The intra-hole space 513 of the through hole 51 extends along a straight line passing through the center of the first opening 511 and the center of the second opening 512. More specifically, the intra-hole space 513 may extend in one direction from the first opening 511 to the second opening 512, as shown in FIG. 2, for example. The intra-hole space 513 may also extend along a straight line L passing through the center of the first opening 511 and the center of the second opening 512, while being curved or bent between the first opening 511 and the second opening 512, as shown in FIG. 3, for example.

[0034] 2, the through-hole 51 in the polymer porous body 5 of this embodiment has a first opening 511 provided in a first end face 52 of the polymer porous body 5 and a second opening 512 provided in a back surface 53 of the first end face 52. Further, an inner hole space 513 connecting the first opening 511 and the second opening 512 extends in approximately one direction along a straight line perpendicular to the first end face 52.

[0035] In addition, when the polymeric porous body 5 has continuous cells, the openings present on the surface of the polymeric porous body 5 may communicate with each other through the continuous cells. However, such continuous cells are formed by connecting a large number of bubbles generated in the polymer body during the manufacturing process of the polymeric porous body 5. Therefore, there may be a large number of openings that communicate with one opening through the continuous cells. Furthermore, since the continuous cells are formed by connecting a large number of bubbles in a disorderly manner as described above, the path from one opening to another opening is usually bent in a disorderly manner and rarely extends along a specific direction like the intra-pore space 513 of the through-hole 51. In this way, the through-hole 51 of the polymeric porous body 5 has a structure completely different from that of the continuous cells, and a person skilled in the art can easily distinguish between the two.

[0036] The opening diameter of the through hole 51 is preferably 0.1 mm or more and 1 mm or less. In this case, a large number of through holes 51 can be formed in the polymer porous body 5 while ensuring the rigidity of the polymer porous body 5, and the water permeability of the polymer porous body 5 can be further improved. From the same viewpoint, the interval between adjacent through holes 51 is preferably 0.5 mm or more and 3 mm or less. The opening diameter of the through hole 51 refers to the maximum diameter of the opening of the through hole 51 formed in the surface of the polymer porous body 5, that is, the distance between two points on the edge of the opening of the through hole 51 that are determined to be the largest distance from each other.

[0037] When the microorganism carrier 3 is composed only of a porous polymer body 5, the porous polymer body 5 preferably has a hardness H that satisfies the following formula (1). H≧ghπ×10 -2 (1)

[0038] In the above formula (1), H is the hardness (unit: N) of the polymeric porous body 5 according to the A method defined in JIS K6400-2:2012, h is the maximum filling height (unit: mm) of the microorganism carrier 3, and g is the standard gravitational acceleration constant (unit: m / s 2), where π is the circular constant. The maximum filling height h of the microorganism carriers 3 refers to the height of the uppermost microorganism carrier 3 when the lowest microorganism carrier 3 in the fermenter 2 is used as the reference.

[0039] The polymer porous body 5 having a hardness H within the specific range is unlikely to be crushed even when filled to a filling height of h in the fermenter 2. Therefore, by using such a polymer porous body 5 as the microbial carrier 3, the microbial carrier 3 can be packed more densely in the fermenter 2 while ensuring the water permeability of the microbial carrier 3. As a result, the fermentation efficiency of the water W to be treated can be further improved.

[0040] The method for producing the microorganism carrier 3 is not particularly limited and may take various forms. For example, a polymeric porous body 5 having through-holes 51 may be produced by using a mold configured to form the through-holes 51, and the microorganism carrier 3 may be produced using this polymeric porous body 5. When producing the microorganism carrier 3 from the polymeric porous body 5, the polymeric porous body 5 may be molded into a desired shape or a frame may be attached to the polymeric porous body 5, as necessary. Also, the polymeric porous body 5 having the through-holes 51 may be used as it is as the microorganism carrier 3.

[0041] 4, for example, a porous polymer body 5 and a drilling tool 6 having a rod-shaped insertion part 61 are prepared, and the insertion part 61 is pressed into the porous polymer body 5 to form through-holes 51 in the porous polymer body 5, and then the porous polymer body 5 is used to produce a microorganism carrier 3. In this case, the structure of the mold used to produce the porous polymer body 5 can be simplified. Furthermore, the opening diameter, interval, number, etc. of the through-holes 51 can be adjusted by the shape, etc. of the insertion part 61 of the drilling tool 6, so that a porous polymer body 5 having through-holes 51 of a desired form can be easily obtained.

[0042] The number, shape, arrangement, etc. of the piercing parts 61 in the drilling tool 6 are not particularly limited, and may be appropriately set according to the desired form of the through hole 51. For example, as shown in FIG. 4, the drilling tool 6 of this embodiment has a flat tool base 62 and a plurality of piercing parts 61 protruding from the tool base 62. The piercing parts 61 have a needle-like shape with a sharp tip. The maximum diameter of the piercing parts 61 can be appropriately selected, for example, within a range of 0.1 mm or more and 1 mm or less. In addition, the interval between adjacent piercing parts 61 can be appropriately selected, for example, within a range of 0.5 mm or more and 3 mm or less.

[0043] When such a drilling tool 6 is pressed into the polymer porous body 5, the polymer porous body 5 is compressed by the drilling tool 6. When the drilling tool 6 is further pressed into the polymer porous body 5, the piercing part 61 is pierced into the polymer porous body 5. At this time, when the polymer porous body 5 is uniformly compressed by the drilling tool 6, a through hole 51 extending in one direction from the first opening 511 to the second opening 512 as shown in Fig. 2 is formed in the polymer porous body 5. When the compression of the polymer porous body 5 is non-uniform, a through hole 51 curved between the first opening 511 and the second opening 512 as shown in Fig. 3 is formed in the polymer porous body 5.

[0044] The microorganisms supported on the microbial carriers 3 may be appropriately selected depending on the type of organic matter in the water to be treated W and the desired mode of fermentation. From the standpoint of more reliably obtaining the effect of promoting fermentation by the fermentation apparatus 1, it is preferable that the microorganisms supported on the microbial carriers 3 include organic matter assimilation bacteria that have the property of fermenting the organic matter in the water to be treated W, and electron-emitting bacteria that have the property of transferring electrons taken in from the outside to the organic matter assimilation bacteria. In this case, the transfer of electrons between the electron-emitting bacteria and the organic matter assimilation bacteria can promote the fermentation of organic matter by the organic matter assimilation bacteria.

[0045] The type of organic matter assimilation bacteria is not particularly limited. For example, the microbial carrier 3 in the fermentation apparatus 1 of this embodiment supports methanogens as organic matter assimilation bacteria, and is configured to ferment organic matter in the water to be treated W and generate biogas containing methane. Examples of methanogens include Methanobacterium and Methanosarcina.

[0046] Electron-emitting bacteria have the property of transferring electrons taken in from the outside to organic matter-utilizing bacteria. Examples of microorganisms having this property include Morganella morganii and Proteus mirabilis.

[0047] The fermentation apparatus 1 of this embodiment has a microorganism carrier 3 that is conductive and includes a polymeric porous body 5 having through-holes 51. Therefore, the effect of improving water permeability due to the through-holes 51 and the effect of facilitating electron transfer act synergistically, and the fermentation of organic matter by the microorganisms can be promoted.

[0048] (Embodiment 2) In this embodiment, examples of other aspects of the polymeric porous body will be described. Note that, among the symbols used in this embodiment and the following embodiments, the same symbols as those used in the previous embodiments represent the same components, etc. as those in the previous embodiments, unless otherwise specified.

[0049] The polymer porous body 502 of this embodiment has a rectangular parallelepiped shape as shown in Fig. 5. The polymer porous body 502 also has a plurality of through holes 54 (54a, 54b, 54c) including a first through hole 54a extending in a first direction and a second through hole 54b extending in a second direction different from the first direction.

[0050] More specifically, the polymer porous body 502 of this embodiment has three types of through holes 54, a first through hole 54a, a second through hole 54b, and a third through hole 54c, which extend in different directions. The first through hole 54a extends in a first direction from the first end face 52 of the polymer porous body 502 toward the back face 53 of the first end face 52. That is, the first through hole 54a has an opening in the first end face 52 and the back face 53 of the first end face 52 of the polymer porous body 502, and extends along a straight line connecting the centers of these openings.

[0051] Similarly, the second through hole 54b extends in a second direction from a second end face 55 adjacent to the first end face 52 toward a back face 56 of the second end face 55. That is, the second through hole 54b has an opening in the second end face 55 and the back face 56 of the second end face 55, and extends along a straight line connecting the centers of these openings. Moreover, the third through hole 54c extends in a third direction from a third end face 57 adjacent to both the first end face 52 and the second end face 55 toward a back face 58 of the third end face 57. That is, the third through hole 54c has an opening in the third end face 57 and the back face 58 of the third end face 57, and extends along a straight line connecting the centers of these openings.

[0052] As in this embodiment, by providing the polymeric porous body 502 with a plurality of through holes 54 extending in different directions, even if the microorganism carriers in the fermenter are oriented in a direction that makes it difficult for the water to be treated to enter any of the through holes 54, the water to be treated can enter the other through holes 54. As a result, the water permeability of the microorganism carriers can be further improved, and the fermentation efficiency can be further improved.

[0053] When a plurality of through holes 54 having different extending directions are provided in the polymer porous body 502 as in this embodiment, each through hole 54 may or may not intersect with the through holes 54 other than the through hole 54. The extending direction of each through hole 54 may be different from the extending direction of the through holes 54 other than the through hole 54. For example, in the rectangular parallelepiped polymer porous body 502, when the direction from the first end face 52 to the back face 53 of the first end face 52 is defined as the first direction, the second direction may be a direction from any side of the first end face 52 to the center of gravity of the polymer porous body 502, or a direction from any vertex of the first end face 52 to the center of gravity of the polymer porous body 502. A direction other than these directions may also be the second direction.

[0054] (Embodiment 3) In this embodiment, an example of a fermentation apparatus 103 equipped with an electrode 7 will be described. As shown in Fig. 6, the fermentation apparatus 103 of this embodiment has a fermentation tank 2, a partition plate 21 arranged in the fermentation tank 2, a microorganism carrier 3 placed on the partition plate 21, and a water-to-be-treated spraying section 4 arranged above the microorganism carrier 3. A gas outlet pipe 24 is provided in the upper space 22 of the fermentation tank 2, and a water-to-be-treated outlet pipe 25 is provided in the lower space 23 of the fermentation tank 2. The configurations of these parts in the fermentation apparatus 103 of this embodiment are similar to those of the fermentation apparatus 1 of the first embodiment.

[0055] Electrodes 7 including a cathode 71 (71a, 71b) and an anode 72 (72a, 72b) are disposed in the fermenter 2. The electrodes 7 are in contact with the microbial carriers 3. The electrodes 7 may be disposed, for example, so as to penetrate the gaps of the microbial carriers 3, or may be disposed so as to penetrate the microbial carriers 3.

[0056] The cathode 71 and the anode 72 are made of a conductor or a semiconductor. Between the cathode 71 and the anode 72, a current path is formed by the water W to be treated flowing along the surface of the microbial carrier 3. Therefore, by applying a voltage between the cathode 71 and the anode 72 and passing a current, the cathode 71 can supply electrons to electron transfer bacteria present in the vicinity thereof, and the water W to be treated that comes into contact with the cathode 71 can be reduced. This can further increase the fermentation efficiency of organic matter.

[0057] The arrangement, shape and structure of the cathode 71 and the anode 72 may take various forms. For example, the number of cathodes 71 arranged in the fermenter 2 may be one or two or more. When two or more cathodes 71 are arranged in the fermenter 2, these cathodes 71 may be arranged at intervals from each other in the vertical direction or may be arranged at intervals from each other in the horizontal direction.

[0058] Similarly, the number of anodes 72 arranged in the fermenter 2 may be one or may be two or more. When two or more anodes 72 are arranged in the fermenter 2, these anodes 72 may be arranged at intervals from each other in the vertical direction or may be arranged at intervals from each other in the horizontal direction. Furthermore, the number of cathodes 71 and the number of anodes 72 arranged in the fermenter 2 may be the same or different from each other.

[0059] The orientation of the cathode 71 and the anode 72 is not particularly limited, and may extend in a horizontal direction or in a direction inclined relative to the horizontal direction, for example. From the viewpoint of distributing the water W to be treated, which has been reduced at the cathode 71, more uniformly throughout the fermenter 2, it is preferable that the cathode 71 and the anode 72 extend in a horizontal direction. Note that the "horizontal direction" mentioned above includes not only a direction strictly perpendicular to the vertical direction, but also a direction inclined from the vertical direction to an extent that is generally recognized as horizontal. In other words, the "horizontal direction" in this specification is a concept that includes a direction that is substantially recognized as horizontal.

[0060] The cathode 71 and the anode 72 in this embodiment are disposed in a plane perpendicular to the up-down direction of the fermenter 2. Therefore, by disposing the fermenter 2 so that its up-down direction is parallel to the vertical direction, the cathode 71 and the anode 72 can be extended in the horizontal direction.

[0061] Of the electrodes 7 arranged in the fermenter 2, the uppermost electrode 7 is preferably the cathode 71. That is, when a plurality of cathodes 71 are arranged in the fermenter 2, it is preferable that any one of the plurality of cathodes 71 is arranged above the anode 72. Furthermore, when a plurality of anodes 72 are arranged in the fermenter 2, it is preferable that the cathode 71 is arranged above these plurality of anodes 72.

[0062] For example, the fermentation apparatus 103 of this embodiment has two cathodes 71 (71a, 71b) and two anodes 72 (72a, 72b), and these electrodes 7 are arranged at a certain interval in the vertical direction. Furthermore, the first cathode 71a is arranged at the top of the four electrodes 7, and the first anode 72a, the second cathode 71b, and the second anode 72b are arranged below the first cathode 71a in this order.

[0063] In this way, by arranging the cathode 71 at the topmost position among the multiple electrodes 7, the water W to be treated that has been reduced at the cathode 71 can be supplied below the cathode 71. The water W to be treated that has been reduced at the cathode 71 can supply electrons to the electron-emitting bacteria in the microbial carriers 3. Therefore, the electron-emitting bacteria that have received electrons via the water W to be treated can transfer the electrons to the organic matter assimilation bacteria present around them, thereby promoting the fermentation of organic matter by the organic matter assimilation bacteria even in locations relatively far from the cathode 71. As a result, the fermentation apparatus 103 can promote the fermentation of organic matter through the interaction between the electron-emitting bacteria and the organic matter assimilation bacteria over a wide range within the fermenter 2, and can ferment the organic matter in the water W to be treated more efficiently.

[0064] At least one of the cathode 71 and the anode 72 is preferably configured to be able to change its position in the vertical direction. In this case, for example, when attaching the cathode 71 and the anode 72 during the assembly work of the fermentation apparatus 103, the vertical positions of these electrodes 7 can be adjusted to reliably bring the cathode 71 and the anode 72 into contact with the microorganism carrier 3. By bringing the cathode 71 and the anode 72 into contact with the microorganism carrier 3, a current path is more likely to be formed between the cathode 71 and the anode 72. As a result, electrons are more likely to be supplied from the cathode 71 to the electron-emitting bacteria, and reduction of the water W to be treated in the cathode 71 is more likely to occur, so that the effect of improving fermentation efficiency can be more reliably obtained.

[0065] The microorganism carrier 3 is preferably pressed by the cathode 71 and the anode 72. For example, the microorganism carrier 3 in this embodiment is pressed in the vertical direction by the cathode 71 and the anode 72, and is filled in the fermenter 2 in a state slightly compressed from its natural state.

[0066] In this way, by pressing the microbial carriers 3 with the cathode 71 and the anode 72, adjacent microbial carriers 3 are more likely to come into contact with each other in the fermenter 2. When adjacent microbial carriers 3 come into contact with each other, a current path from the cathode 71 to the anode 72 is more likely to be formed by the water to be treated W flowing along the surface of the microbial carrier 3. As a result, electrons are more likely to be supplied from the cathode 71 to the electron-emitting bacteria, and reduction of the water to be treated W in the cathode 71 is more likely to occur, so that the effect of improving fermentation efficiency can be more reliably obtained.

[0067] Next, an example of the operation of the fermentation apparatus 103 of this embodiment will be described. When operating the fermentation apparatus 103 of this embodiment, the water to be treated W is sprayed from the water to be treated spraying section 4 into the fermentation tank 2, and a voltage is applied between the cathode 71 and the anode 72. The water to be treated W flows downward along the surface of the microorganism carrier 3. A current path is formed between the cathode 71 and the anode 72 by this water to be treated W. When the microorganism carrier 3 is made of a conductor and / or a semiconductor, the microorganism carrier 3 can also form a part of the current path between the cathode 71 and the anode 72.

[0068] When a current path is formed between the cathode 71 and the anode 72, a current flows between these electrodes 7, and electrons are supplied to the electron-emitting bacteria present in the vicinity of the cathode 71. The electron-emitting bacteria that receive electrons directly from the cathode 71 transfer the electrons to the organic matter assimilation bacteria supported on the microbial carrier 3. The organic matter assimilation bacteria that receive the electrons can then efficiently ferment the organic matter in the water W to be treated.

[0069] Furthermore, when a current flows between the cathode 71 and the anode 72, the water to be treated W in contact with the cathode 71 is reduced. The water to be treated W reduced at the cathode 71 flows down along the surface of the microbial carrier 3 and is diffused throughout the fermenter 2. When the water to be treated W reduced at the cathode 71 comes into contact with the electron-emitting bacteria supported on the microbial carrier 3, the electron-emitting bacteria receive electrons derived from the cathode 71 from the water to be treated W. Then, the organic matter assimilation bacteria surrounding the electron-emitting bacteria receive the electrons derived from the cathode 71, thereby promoting the fermentation of organic matter in the water to be treated W even in places relatively far from the cathode 71.

[0070] As described above, the fermentation apparatus 103 of this embodiment can promote the fermentation of organic matter through interaction between the electron-emitting bacteria and the organic matter-utilizing bacteria over a wide area within the fermentation tank 2, thereby efficiently fermenting the organic matter in the water to be treated W.

[0071] Although examples of the aspects of the fermentation apparatus have been described based on embodiments 1 to 3, the specific aspects of the fermentation apparatus of the present invention are not limited to the above-mentioned embodiments, and the configuration can be appropriately changed without departing from the gist of the apparatus. [Explanation of symbols]

[0072] 1, 103 Fermentation equipment 2 Fermentation tank 3. Microbial carriers 4 Treated water spraying section 5, 502 Porous polymers 51, 54 Through holes

Claims

1. A fermentation apparatus configured to ferment organic matter in water to be treated by microorganisms, A fermentation tank; A plurality of microbial carriers arranged in the fermenter and configured to be capable of supporting the microorganisms; a water-to-be-treated spraying section for spraying the water to be treated onto the microorganism carrier; A fermentation apparatus, wherein the microorganism carrier has electrical conductivity and comprises a polymeric porous body having through-holes.

2. The fermentation apparatus according to claim 1 , wherein the untreated water spraying section is disposed above the microorganism carriers.

3. The fermentation apparatus of claim 1, wherein the polymeric porous body has a plurality of through holes including a first through hole extending in a first direction and a second through hole extending in a second direction different from the first direction.

4. The fermentation apparatus according to claim 1 , wherein the opening diameter of the through hole is 0.1 mm or more and 1 mm or less.

5. The fermentation apparatus according to claim 1 , wherein the distance between adjacent through holes is 0.5 mm or more and 3 mm or less.

6. The fermentation apparatus according to claim 1 , wherein the polymeric porous body has a shape selected from the group consisting of a cylindrical shape, a rectangular parallelepiped shape, and a spherical shape.

7. The fermentation apparatus according to claim 5 , wherein the aspect ratio of the polymeric porous body is within the range of 0.5 or more and 2 or less.

8. The fermentation apparatus according to claim 1 , wherein the microorganism carrier is composed only of the polymeric porous body.

9. The fermentation apparatus according to claim 1 , wherein the polymeric porous body has a hardness H that satisfies the following formula (1): H≧ghπ×10 -2 ・・・(1) (In the above formula (1), H is the hardness (unit: N) of the polymeric porous body according to the A method defined in JIS K6400-2:2012, h is the maximum filling height (unit: mm) of the microorganism carrier, and g is the standard gravitational acceleration constant (unit: m / s ２ ), where π is the constant of the circumference of a circle.

10. The fermentation apparatus of claim 1 , further comprising electrodes disposed within the fermenter and in contact with the microbial carriers.

11. A method for producing a microbial carrier for a fermentation apparatus according to any one of claims 1 to 10, A conductive porous polymer body and a drilling tool having a rod-shaped insertion portion are prepared; The insertion portion is pressed into the polymeric porous body to form a through hole in the polymeric porous body; A method for producing a microbial carrier, comprising obtaining a microbial carrier using the porous polymer material.

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