Housing for microbial fuel cell, microbial fuel cell, and stacked microbial fuel cell

Abstract

To provide a housing for a microbial fuel cell that can form multiple layers of the microbial fuel cell in order to further increase the electrical output obtained.SOLUTION: A microbial fuel cell housing 10 includes a container 15 having a bottom portion 11, a side wall portion 13 extending upward from a periphery 12 of the bottom portion 11, and an opening 14 with an open top, and a lid member 16 covering the opening 14 of the container 15, and the side wall portion 13 slopes outward as it extends upward and has an opening 17 that penetrates the side wall portion 13 at a predetermined height, and the lid member 16 has a mounting area 18 on the upper surface of the lid member 16 where another container 15 can be placed, and a through hole 20 that opens into a peripheral area 19 outside the mounting area 18 and penetrates the lid member 16.SELECTED DRAWING: Figure 3

Description

[Technical Field]

[0001] The present disclosure relates to a housing for a microbial fuel cell, a microbial fuel cell, and a stacked microbial fuel cell. [Background technology]

[0002] Microbial fuel cells (also known as plant microbial fuel cells or plant cells) that use anaerobic current-producing bacteria (also known as electricity-generating bacteria, current-generating bacteria, or current-producing bacteria) are known. Plant roots secrete organic matter such as sugars and organic acids, which are photosynthetic products. In microbial fuel cells, current-producing bacteria living near the negative electrode ingest this organic matter (electron donors) along with water, generating carbon dioxide, protons, and electrons, which are then donated to the negative electrode (anode electrode) (Reaction Formula 1). The electrons are transferred from the negative electrode to the positive electrode via an external circuit. At the positive electrode (cathode electrode), oxygen (electron acceptor) and protons accept the electrons, generating water (Reaction Formula 2). Through this series of reactions, the microbial fuel cell outputs electricity. Negative electrode: Organic matter +2H2O→CO2+4H + +4e - (Reaction Scheme 1) Positive electrode: O2+4H + +4e - →2H2O (Reaction 2)

[0003] To achieve the above series of reactions, the negative electrode must be in contact with soil containing organic matter and water at least partially to receive the electrons and protons generated by the electrogenic bacteria, and the positive electrode must be in contact with air and water at least partially to take in oxygen and protons. Typically, the negative electrode is placed inside the soil and the positive electrode is placed on the surface of the soil.

[0004] The plant microbial fuel cell (microbial fuel cell) shown in Patent Document 1 (Figs. 4-6, 0018) has a carbon electrode divided into three parts that constitutes the anode electrode (negative electrode). The cathode electrode (positive electrode) is further divided into three parts. The microbial fuel cell has three battery sections, each consisting of a pair of divided anode and cathode electrodes. Each battery section is connected in series by connecting the anode electrode of the left battery section to the cathode electrode of the central battery section, and the anode electrode of the central battery section to the cathode electrode of the right battery section, with a conductor that does not have a load such as a resistor. The anode electrode of the right battery section and the cathode electrode of the left battery section are connected by an external circuit that has an electrical load such as a resistor. This structure allows multiple batteries to be connected in series, thereby increasing the electrical output. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Patent Publication No. 2022-033628 Summary of the Invention [Problem to be solved by the invention]

[0006] To obtain output from each cell unit, organic matter secreted from plant roots is required, and therefore plants need sunlight for photosynthesis. However, all of the microbial fuel cells in Patent Document 1 have plants planted in the cell units. When microbial fuel cells are stacked in multiple layers to further increase the electrical output obtained, the microbial fuel cells in the lower layers do not receive sunlight and do not secrete organic matter, making it impossible to further increase the electrical output.

[0007] The present disclosure has been made in consideration of the above-mentioned circumstances, and the purpose of the present disclosure is to provide a microbial fuel cell housing and microbial fuel cell that can be multi-layered to further increase the electrical output obtained, as well as a stacked microbial fuel cell formed by stacking the microbial fuel cells. [Means for solving the problem]

[0008] A first aspect of the present disclosure is a container having a bottom surface, a sidewall extending upward from a periphery of the bottom surface, and an opening with an open top; A microbial fuel cell housing comprising: a lid member that covers the opening of the container; the side wall portion is inclined outwardly as it extends upward, and has an opening penetrating the side wall portion at a predetermined height position; The present invention relates to a housing for a microbial fuel cell, characterized in that the lid member has a mounting area on the upper surface of the lid member where another container can be placed, and a through hole that opens into an outer peripheral area outside the mounting area and penetrates the lid member.

[0009] The microbial fuel cell housing includes a container having a bottom, a sidewall extending upward from the periphery of the bottom, and an opening at the top; and a lid member covering the opening of the container. The sidewall slopes outward as it extends upward and has an opening penetrating the sidewall at a predetermined height. The lid member has a through-hole that opens to an outer peripheral region outside the mounting area and penetrates the lid member. This allows water containing nutrients (organic matter) for current-generating bacteria and air (oxygen) to be supplied into the container from above the microbial fuel cell housing through the through-hole. Because water accumulates up to the bottom edge of the opening, water is secured within the container at a height (H1) from the top surface (reference plane) of the bottom to the bottom edge of the opening, and air (oxygen) is secured at a height (H2) from the bottom edge of the opening to the upper edge of the sidewall. Therefore, by appropriately arranging soil containing current-generating bacteria, a negative electrode, and a positive electrode within the container, the microbial fuel cell can output electricity. The lid member has a mounting area on the top surface of the lid member where another container can be placed. This allows other containers to be placed in the mounting area, creating a multi-layer microbial fuel cell. Furthermore, water containing organic matter that overflows from the opening flows through the through-holes into the microbial fuel cell in the lower layer, allowing each microbial fuel cell to output electricity. Furthermore, since the negative and positive electrodes are arranged in pairs within the container and are separated from the negative and positive electrodes in other containers, connecting multiple microbial fuel cells does not result in a short circuit. Therefore, connecting multiple microbial fuel cells can further increase electrical output. Furthermore, the sidewalls are inclined outward as they extend upward, allowing the containers to be stacked, making them convenient for storage, transportation, and the like.

[0010] In a first aspect of the present disclosure, the bottom surface portion is a substantially rectangular shape having four first sides, The side wall portions may extend obliquely upward from each of the four first side edges.

[0011] This allows the microbial fuel cell housings to be arranged in a grid pattern, which increases area efficiency and further increases the electrical output of the microbial fuel cell.

[0012] In the first aspect of the present disclosure, further comprising: the side wall portion has the opening on each of four faces, the lid member includes a first restricting portion that locally contacts or is close to the other container placed thereon to restrict horizontal displacement of the other container, and a second restricting portion that locally contacts or is close to the container whose opening is covered by the lid member to restrict horizontal displacement of the lid member, The mounting area may have a substantially rectangular shape that is substantially the same as the bottom surface portion, and the lid member may have the through-holes near each of four second side edges of the mounting area.

[0013] In a first aspect of the present disclosure, the side wall portion has the opening on each of four faces, the lid member includes a second restriction portion that locally contacts or is close to the container whose opening is covered by the lid member and restricts horizontal displacement of the lid member; the bottom surface portion includes third restriction portions that protrude downward from each of the four first side edges, the mounting area has a substantially rectangular shape that is substantially the same as the inner periphery of the third restricting portion, the third regulating portion, when the container is placed on the placement area of ​​another lid member, locally contacts or comes close to the placement area of ​​the other lid member to regulate horizontal displacement of the container; The cover member may have the through-holes near each of the four second side edges of the placement area.

[0014] The first and second restriction units or the second and third restriction units allow two or more microbial fuel cell casings to be stacked together, and even if the casings tilt for some reason, the individual microbial fuel cell casings are unlikely to come loose. Furthermore, the sidewalls have openings on each of their four faces, the mounting area is roughly rectangular and has the same shape as the bottom surface, and the lid member has through-holes near each of the four second side edges of the mounting area. Therefore, even if the stacked microbial fuel cell casings tilt, water containing nutrients (organic matter) for current-generating bacteria can be supplied to the microbial fuel cell below through the openings and through-holes on the tilted side. Therefore, even if the multi-layered microbial fuel cell casings tilt, each microbial fuel cell can stably output electricity.

[0015] In a first aspect of the present disclosure, the cover member has a groove in the outer peripheral region, The through-hole may be formed so as to communicate with the groove.

[0016] This allows water supplied from above the microbial fuel cell housing to collect in the groove, allowing water to be smoothly supplied into the container.

[0017] A second aspect of the present disclosure is A housing for a microbial fuel cell according to the first aspect of the present disclosure; In the microbial fuel cell, the container contains soil containing current-generating bacteria, a negative electrode, and a positive electrode, When the upper surface of the bottom surface portion is used as a reference surface, The height (H3) from the reference surface to the top surface of the soil is approximately the same as the height (H1) from the reference surface to the lower end of the opening, a height (H4) from the reference surface to the upper surface of the positive electrode is greater than a height (H1) from the reference surface to the lower end of the opening; a height (H5) from the reference surface to the lower surface of the positive electrode is approximately equal to or lower than a height (H1) from the reference surface to the lower end of the opening; The present invention relates to a microbial fuel cell, characterized in that the negative electrode is positioned closer to the bottom surface than the positive electrode.

[0018] As a result, water and organic matter are supplied to the negative electrode, reaction 1 occurs, oxygen (O2) is released on the top surface of the positive electrode, and protons (H + ) is supplied to produce reaction 2, allowing the microbial fuel cell to output electricity.

[0019] A third aspect of the present disclosure is Two or more microbial fuel cells according to the second aspect of the present disclosure are provided; The present invention relates to a stacked microbial fuel cell, characterized in that a container of another microbial fuel cell is placed on the placement area of ​​one microbial fuel cell.

[0020] When water containing organic matter is supplied from above the stacked microbial fuel cell, the water containing organic matter is sequentially supplied from the upper microbial fuel cell to the lower microbial fuel cell, allowing the microbial fuel cells to be stacked in multiple layers, further increasing the electrical output obtained.

[0021] In a third aspect of the present disclosure, A planting area may be provided in the area where the topmost microbial fuel cell is placed.

[0022] This means that, when there is sunlight and rainfall, water containing organic matter can be supplied from the planted area to each microbial fuel cell in the stacked microbial fuel cell, allowing for continuous output of larger amounts of electricity with minimal maintenance work. [Brief explanation of the drawings]

[0023] [Figure 1] 1 shows the appearance of a housing for a microbial fuel cell according to this embodiment. [Figure 2] 1 shows the appearance of one embodiment of the container of the present embodiment. [Figure 3] 2 shows a cross-sectional view taken along line AA in FIG. 1. [Figure 4] 1 shows a cross-sectional view of another embodiment of a housing for a microbial fuel cell. [Figure 5] The containers are stacked. [Figure 6] 1 shows a microbial fuel cell according to this embodiment. [Figure 7]1 shows a stacked microbial fuel cell according to this embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0024] Preferred embodiments of the present disclosure will be described in detail below. Note that the embodiments described below do not unduly limit the content of the present disclosure described in the claims, and not all of the configurations described in the embodiments are necessarily essential as means for solving the problems of the present disclosure.

[0025] 1 to 4 respectively show the appearance of the casing 10 for a microbial fuel cell of this embodiment, the appearance of a container 15 of this embodiment, an AA cross-sectional view of Fig. 1, and a cross-sectional view of another embodiment of the casing 10 for a microbial fuel cell. The casing 10 for a microbial fuel cell of this embodiment comprises a container 15 having a bottom surface 11, a side wall portion 13 extending upward from a periphery 12 of the bottom surface 11, and an opening 14 with an open top, and a lid member 16 covering the opening 14 of the container 15. In the casing 10 for a microbial fuel cell, the side wall portion 13 slopes outward as it extends upward and has an opening 17 penetrating the side wall portion 13 at a predetermined height position, and the lid member 16 has a mounting area 18 on the upper surface of the lid member 16 where another container 15 can be placed, and a through-hole 20 that opens into a peripheral area 19 outside the mounting area 18 and penetrates the lid member 16.

[0026] The microbial fuel cell housing 10 comprises a container 15 having a bottom surface 11, a sidewall 13 extending upward from a periphery 12 of the bottom surface 11, and an opening 14 open at the top, and a lid member 16 covering the opening 14 of the container 15, the sidewall 13 sloping outward as it extends upward and having an opening 17 penetrating the sidewall 13 at a predetermined height, and the lid member 16 having a through-hole 20 opening in an outer peripheral region 19 outside the mounting region 18 and penetrating the lid member 16. This allows water containing nutrients (organic matter) for current-generating bacteria and air (oxygen) to be supplied into the container 15 from above the microbial fuel cell housing 10 through the through-hole 20. Because water accumulates up to the bottom of the opening 17, the container 15 contains water up to a height (H1) from the top of the bottom portion 11 to the bottom of the opening 17, and air (oxygen) up to a height (H2) from the bottom of the opening 17 to the upper edge 21 of the sidewall portion 13 (FIG. 3). Therefore, by appropriately arranging soil 27 containing current-generating bacteria, a negative electrode 28, and a positive electrode 29 in the container 15, electricity can be output as a microbial fuel cell 30 (FIG. 6). The lid member 16 has a mounting area 18 on the top surface of the lid member 16 where another container 15 can be placed (FIGS. 1, 3, and 4). This allows other containers 15 to be placed in the mounting area 18, making it possible to create a multi-layered microbial fuel cell 30 (FIG. 7). Furthermore, water containing organic matter that overflows from the opening 17 flows into the microbial fuel cells 30 in the lower layer through the through-holes 20, allowing each microbial fuel cell 30 to output electricity. Furthermore, the negative electrode 28 and positive electrode 29 are arranged in pairs within a container, and the negative electrode 28 and positive electrode 29 in other containers are isolated, so that connecting multiple microbial fuel cells 30 does not cause a short circuit. Therefore, connecting multiple microbial fuel cells 30 can further increase the electrical output. Furthermore, the side wall 13 slopes outward as it goes upward, allowing the containers 15 to be stacked (Figure 5), making storage, transportation, etc. convenient.

[0027] The height (H1) from the top surface of the bottom portion 11 to the lower end of the opening 17 is not particularly limited as long as it can secure soil 27 containing current-generating bacteria, nutrients (organic matter), and water, and although it depends on the size of the microbial fuel cell casing 10, it is preferably 10 mm or more, more preferably 20 mm or more, and even more preferably 30 mm or more. The height (H2) from the lower end of the opening 17 to the upper edge 21 of the side wall portion 13 is not particularly limited as long as it can secure air (oxygen) above the top surface of the soil (water surface), and although it also depends on the size of the microbial fuel cell casing 10, it is preferably 5 mm or more, more preferably 10 mm or more, and even more preferably 15 mm or more. The shape of the opening 17 is not particularly limited and may be, for example, circular, elliptical, rectangular, polygonal, etc., and may extend to the upper edge 21 of the side wall portion 13.

[0028] In the microbial fuel cell housing 10 of this embodiment, the bottom surface portion 11 is a substantially rectangular shape having four first side edges 12, and the side wall portions 13 may extend obliquely upward from each of the four first side edges 12 (FIGS. 1 to 4). The shape of the lid member 16 is not particularly limited, and may be, for example, a substantially rectangular shape when viewed from above (FIG. 1).

[0029] This allows the microbial fuel cell casings 10 to be arranged in a grid pattern, which increases area efficiency and allows the electrical output of the microbial fuel cell 30 to be further increased.

[0030] In the microbial fuel cell housing 10 of this embodiment, the side wall portion 13 further has an opening 17 on each of the four sides, the lid member 16 has a first regulating portion 22 that locally abuts or is close to another container 15 placed on it to regulate horizontal displacement of the other container 15, and a second regulating portion 23 that locally abuts or is close to the container 15 whose opening 14 is covered by the lid member 16 to regulate horizontal displacement of the lid member 16, the mounting area 18 is approximately rectangular in shape and approximately the same as the bottom surface portion 11, and the lid member 16 may have a through hole 20 near each of the four second side edges 24 of the mounting area 18 (Figures 1 and 3). In addition, the side wall portion 13 has an opening 17 on each of the four surfaces, the lid member 16 has a second regulating portion 23 that locally abuts or is close to the container 15 whose opening 14 is covered by the lid member 16, thereby regulating horizontal displacement of the lid member 16, the bottom portion 11 has a third regulating portion 25 that protrudes downward from each of the four first side edges 12, the mounting area 18 is approximately rectangular and has approximately the same shape as the inner circumference of the third regulating portion 25, and when the container 15 is placed on the mounting area 18 of another lid member 16, the third regulating portion 25 locally abuts or is close to the mounting area 18 of the other lid member 16, thereby regulating horizontal displacement of the container 15, and the lid member 16 may have a through hole 20 near each of the four second side edges 24 of the mounting area 18 (Figures 1 and 4). Furthermore, the position of the opening 17 on the side wall portion 13 may be substantially on the perpendicular bisector of the first side edge 12 of the bottom surface portion 11.

[0031] The first restriction member 22 and the second restriction member 23 (FIG. 3) or the second restriction member 23 and the third restriction member 25 (FIG. 4) allow two or more microbial fuel cell casings 10 to be stacked together, and even if the casings tilt for some reason, the individual microbial fuel cell casings 10 are unlikely to come off. Furthermore, the sidewall 13 has an opening 17 on each of its four faces, the mounting area 18 is substantially rectangular and has the same shape as the bottom surface 11, and the lid member 16 has a through-hole 20 near each of the four second side edges 24 of the mounting area 18. Furthermore, the position of the opening 17 on the sidewall 13 is approximately on the perpendicular bisector of the first side edge 12 of the bottom surface 11. Therefore, even if the stacked microbial fuel cell casings 10 tilt, water containing nutrients (organic matter) for current-generating bacteria can be supplied to the microbial fuel cell 30 below through the opening 17 and the through-hole 20 on the tilted side. Therefore, even if the multilayered microbial fuel cell casing 10 tilts, each microbial fuel cell 30 can stably output electricity. The shape of the first restriction portions 22 is not particularly limited, and for example, L-shaped first restriction portions 22 may be provided at the four corners of the mounting area 18 (FIG. 1). This makes it easy to arrange the mounting area 18, through-holes 20, grooves 26, etc. in the lid member 16.

[0032] In the microbial fuel cell housing 10 of this embodiment, the cover member 16 may have a groove 26 in the outer peripheral region 19, and the through-hole 20 may be formed to communicate with the groove 26. In addition, the bottom of the groove 26 may be inclined so as to be lower toward the through-hole 20 (FIGS. 1, 3, and 4).

[0033] This allows water supplied from above the microbial fuel cell housing 10 to collect in the groove 26, allowing water to be supplied smoothly into the container 15.

[0034] The microbial fuel cell 30 (Figure 6) of this embodiment comprises a microbial fuel cell housing 10, and soil 27 containing current-generating bacteria, a negative electrode 28, and a positive electrode 29 within a container 15. When the upper surface of the bottom portion 11 is taken as the reference plane, the height (H3) from the reference plane to the upper surface of the soil 27 is approximately the same as the height (H1) from the reference plane to the lower end of the opening 17, the height (H4) from the reference plane to the upper surface of the positive electrode 29 is higher than the height (H1) from the reference plane to the lower end of the opening 17, the height (H5) from the reference plane to the lower surface of the positive electrode 29 is approximately the same as or lower than the height (H1) from the reference plane to the lower end of the opening 17, and the negative electrode 28 is positioned closer to the bottom portion 11 than the positive electrode 29.

[0035] As a result, water and organic matter are supplied to the negative electrode 28, reaction formula 1 occurs, oxygen (O2) is produced on the top surface of the positive electrode 29, and protons (H + ) is supplied to cause reaction 2, and the microbial fuel cell 30 can output electricity.

[0036] The stacked microbial fuel cell 31 (FIG. 7) of this embodiment includes two or more microbial fuel cells 30, and the container 15 of one microbial fuel cell 30 is placed on the placement area 18 of another microbial fuel cell 30.

[0037] When water containing organic matter is supplied from above the stacked microbial fuel cell 31, the water containing organic matter is sequentially supplied from the upper microbial fuel cell 30 to the lower microbial fuel cell 30, thereby making it possible to stack the microbial fuel cells 30 and further increase the electrical output obtained.

[0038] In the stacked microbial fuel cell 31 of this embodiment, a planting section 32 may be provided in the mounting area 18 of the topmost microbial fuel cell 30.

[0039] As a result, if there is sunlight and rainfall, water containing organic matter can be supplied from the planting area 32 to each microbial fuel cell 30 in the stacked microbial fuel cell 31, allowing for continuous output of larger amounts of electricity with minimal maintenance work. Furthermore, the material provided in the mounting area 18 of the topmost microbial fuel cell 30 is not limited to the planting area 32, as long as it can supply organic matter and water for the current-generating bacteria to carry out Reaction 1, and could also be, for example, livestock manure.

[0040] Although the present embodiment has been described in detail above, it will be readily apparent to those skilled in the art that many modifications are possible without substantially departing from the novel features and advantages of the present disclosure. Therefore, all such modifications are included within the scope of the present disclosure. For example, a term described at least once in the specification or drawings together with a different term having a broader or similar meaning may be replaced with that different term anywhere in the specification or drawings. Furthermore, the configuration of the present embodiment is not limited to that described in the present embodiment, and various modifications are possible. [Explanation of symbols]

[0041] 10 microbial fuel cell housing, 11 bottom surface portion, 12 peripheral edge (first side edge), 13 side wall portion, 14 opening portion, 15 container, 16 lid member, 17 opening portion, 18 mounting area, 19 outer peripheral area, 20 through-hole, 21 upper edge, 22 first restricting portion, 23 second restricting portion, 24 second side edge, 25 third restricting portion, 26 groove, 27 soil, 28 negative electrode, 29 positive electrode, 30 microbial fuel cell, 31 stacked microbial fuel cell, 32 planting portion

Claims

1. a container having a bottom surface, a sidewall extending upward from a periphery of the bottom surface, and an opening with an open top; A microbial fuel cell housing comprising: a lid member that covers the opening of the container; the side wall portion is inclined outwardly as it extends upward, and has an opening penetrating the side wall portion at a predetermined height position; The lid member is characterized in that it has a mounting area on the upper surface of the lid member where another container can be placed, and a through hole that opens into an outer peripheral area outside the mounting area and penetrates the lid member.

2. The microbial fuel cell housing according to claim 1, the bottom surface portion is generally rectangular and has four first sides; A housing for a microbial fuel cell, characterized in that the side wall portion extends diagonally upward from each of the four first side edges.

3. The microbial fuel cell housing according to claim 2, the side wall portion has the opening on each of four faces, The lid member includes a first restricting portion that locally contacts or is close to the other container placed thereon to restrict horizontal displacement of the other container, and a second restricting portion that locally contacts or is close to the container whose opening is covered by the lid member to restrict horizontal displacement of the lid member, A housing for a microbial fuel cell, characterized in that the mounting area is approximately rectangular in shape and is roughly the same as the bottom surface portion, and the lid member has the through holes near each of the four second side edges of the mounting area.

4. The microbial fuel cell housing according to claim 2, the side wall portion has the opening on each of four faces, the lid member includes a second restriction portion that locally contacts or is close to the container whose opening is covered by the lid member and restricts horizontal displacement of the lid member, the bottom surface portion includes third restriction portions that protrude downward from each of the four first side edges, the mounting area has a substantially rectangular shape that is substantially the same as the inner periphery of the third restricting portion, When the container is placed on the placement area of ​​another lid member, the third regulating portion locally abuts or comes close to the placement area of ​​the other lid member to regulate horizontal displacement of the container, A housing for a microbial fuel cell, characterized in that the cover member has the through-holes near each of the four second side edges of the placement area.

5. The microbial fuel cell housing according to claim 1, the cover member has a groove in the outer peripheral region, A housing for a microbial fuel cell, characterized in that the through-hole is formed in communication with the groove.

6. A microbial fuel cell housing according to any one of claims 1 to 5, In the microbial fuel cell, the container contains soil containing current-generating bacteria, a negative electrode, and a positive electrode, When the upper surface of the bottom surface portion is used as a reference surface, The height from the reference surface to the top surface of the soil is approximately the same as the height from the reference surface to the bottom end of the opening, a height from the reference surface to an upper surface of the positive electrode is greater than a height from the reference surface to a lower end of the opening, a height from the reference surface to a lower surface of the positive electrode is approximately equal to or lower than a height from the reference surface to a lower end of the opening, A microbial fuel cell characterized in that the negative electrode is positioned closer to the bottom surface than the positive electrode.

7. Two or more microbial fuel cells according to claim 6 are provided, A stacked microbial fuel cell, characterized in that a container of another microbial fuel cell is placed on the placement area of ​​one microbial fuel cell.

8. The stacked microbial fuel cell according to claim 7, A stacked microbial fuel cell characterized by having a planting area in the mounting area of ​​the topmost microbial fuel cell.

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