A novel biophotocoupling device

Abstract

The application discloses a novel bio-photoelectric coupling device, which comprises a shell, a water inlet formed in the bottom of the shell, and a water outlet formed in the top of the shell; an artificial wetland unit, which comprises a shunt layer and an intermediate substrate layer sequentially laid in the shell from bottom to top, and plants planted in the intermediate substrate layer; the water inlet is located at the bottom of one side of the shunt layer; a microbial fuel cell unit, which comprises an anode layer and a cathode layer, and the anode layer and the cathode layer are electrically connected through an external circuit, the anode layer is located between the shunt layer and the intermediate substrate layer, the cathode layer is located above the intermediate substrate layer, the top of the plants penetrates through the cathode layer and extends out of the shell, and the water outlet is located above the cathode layer. The coupling of the microbial fuel cell unit and the artificial wetland unit can not only remove common pollutants, but also remove composite pollutants such as antibiotics and heavy metal substances, improve the pollutant removal capacity, and realize more economical input and output.

Description

Technical Field

[0001] This invention relates to the fields of microbial fuel cells and constructed wetlands, and in particular to a novel bio-photoelectric coupling device. Background Technology

[0002] Microbial fuel cells (MFCs) can achieve waste disposal and energy recovery through the action of electrogenic bacteria, representing a promising environmental pollution control technology. MFCs use microorganisms as the anode catalyst and typically consist of a biological anode and a chemical cathode. However, MFCs often require artificially prepared microbial nutrient solutions to maintain the normal operation of the electrogenic microorganisms, and the devices themselves have numerous limitations. Due to their inherent characteristics, MFCs generally generate voltages less than 2 volts, limiting their application. Constructed wetlands, on the other hand, have become a focus of attention due to their ease of construction, low cost, and environmental friendliness.

[0003] Constructed wetland technology can effectively remove common pollutants from water bodies through the combined action of microorganisms, plants, and various substrates (generally gravel, soil, zeolite, etc.). In particular, vertical flow constructed wetlands and emergent plants are considered to have great potential for removing common and emerging pollutants from water bodies. However, constructed wetlands operating alone are not ideal in removing some complex pollutants such as heavy metal ions and antibiotics, and the electrogenic bacteria and electrolytes abundant in constructed wetlands are not utilized.

[0004] Therefore, a novel bio-optoelectronic coupling device is proposed. Summary of the Invention

[0005] The purpose of this invention is to provide a novel bio-optoelectronic coupling device, which aims to solve or improve at least one of the above-mentioned technical problems.

[0006] To achieve the above objectives, the present invention provides the following solution: The present invention provides a novel bio-optocoupler device, comprising:

[0007] The outer casing has a water inlet at the bottom and a water outlet at the top.

[0008] An artificial wetland unit includes, from bottom to top, a diversion layer and an intermediate substrate layer laid inside the outer shell, wherein plants are planted in the intermediate substrate layer; the inlet is located at the bottom of one side of the diversion layer.

[0009] A microbial fuel cell unit, comprising an anode layer and a cathode layer, wherein the anode layer and the cathode layer are electrically connected via an external circuit, the anode layer is located between the flow distribution layer and the intermediate matrix layer, the cathode layer is located above the intermediate matrix layer, the top of the plant penetrates the cathode layer and extends out of the outer shell, and the water outlet is located above the cathode layer.

[0010] Preferably, the diversion layer includes a gravel layer and a first soil layer, the gravel layer is laid at the bottom of the outer shell, the first soil layer is laid between the gravel layer and the anode layer, and the inlet is located at the bottom of one side of the gravel layer.

[0011] Preferably, the anode layer includes a plurality of anode graphite particles and a composite electrode of anode carbon felt and titanium wire, wherein the composite electrode of anode carbon felt and titanium wire is laid between the plurality of anode graphite particles, and the plurality of anode graphite particles are laid between the first soil layer and the intermediate matrix layer.

[0012] The cathode layer includes a plurality of cathode graphite particles and a cathode carbon felt and titanium wire composite electrode. The cathode carbon felt and titanium wire composite electrode is laid between the plurality of cathode graphite particles. The plurality of cathode graphite particles are laid above the intermediate matrix layer. The anode carbon felt and titanium wire composite electrode and the cathode carbon felt and titanium wire composite electrode are electrically connected through the external circuit. The top of the plant passes through the plurality of cathode graphite particles and the cathode carbon felt and titanium wire composite electrode. The water outlet is located above the plurality of cathode graphite particles.

[0013] Preferably, the intermediate matrix layer includes a second soil layer located between a plurality of anode graphite particles and a plurality of cathode graphite particles, and the plant is planted in the second soil layer.

[0014] Preferably, the external circuit includes a cathode wire and an anode wire. The anode wire is electrically connected to the anode carbon felt and titanium wire composite electrode. The cathode wire is electrically connected to the cathode carbon felt and titanium wire composite electrode. Both the cathode wire and the anode wire extend outside the outer casing and are electrically connected to a voltage workstation. A variable resistor is electrically connected between the anode wire and the cathode wire, and the variable resistor is connected in parallel with the voltage workstation.

[0015] Preferably, the bottom of the plant root system penetrates sequentially through the second soil layer, several of the anode graphite particles and the anode carbon felt and titanium wire composite electrode, the first soil layer, and extends into the gravel layer.

[0016] Preferably, the second soil layer has a thickness of 10-20cm, the first soil layer has a thickness of 1-4cm, the anode graphite particles have a thickness of 2-6cm, the cathode graphite particles have a thickness of 2-6cm, and the gravel layer has a thickness of 1-5cm.

[0017] Preferably, the gravel particle size of the gravel layer is 2-8 mm.

[0018] Preferably, the particle size of the cathode graphite particles and the anode graphite particles is 3-8 mm.

[0019] Preferably, nylon cloth is laid between the gravel layer and the first soil layer, between the first soil layer and a plurality of anode graphite particles, between a plurality of anode graphite particles and the second soil layer, and between the second soil layer and a plurality of cathode graphite particles.

[0020] This invention discloses the following technical effects: Wastewater is introduced into the casing through the inlet, passing sequentially through a diversion layer, an anode layer, an intermediate matrix layer, and a cathode layer, finally flowing out through the outlet. The diversion layer, intermediate matrix layer, and plants remove common pollutants from the wastewater. The intermediate matrix layer is rich in electrogenic microorganisms, and the growth of the plants simultaneously stimulates the growth of these microorganisms. Organic pollutants in the wastewater provide a carbon source for the microorganisms, thus avoiding the need for additional microbial nutrient solutions to maintain them. The electrogenic microorganisms attach to the anode and cathode layers. The anode layer and its vicinity oxidize organic pollutants and generate electrons. These electrons travel through an external circuit to the cathode layer to reduce heavy metals, thereby removing heavy metal ions, antibiotics, and other complex pollutants from the wastewater, completing both the pollutant removal and power generation processes. This invention couples a biofuel cell unit and an artificial wetland unit, integrating their advantages. It can remove not only common pollutants but also complex pollutants such as heavy metal ions and antibiotics, improving pollutant removal capacity. Simultaneously, it increases the utilization rate of electrogenic microorganisms within the artificial wetland, enhancing the power generation capacity of the microbial fuel cell and achieving a more economical input-output ratio. Attached Figure Description

[0021] The accompanying drawings, which form part of this application, are used to provide a further understanding of this application. The illustrative embodiments and descriptions of this application are used to explain this application and do not constitute an undue limitation of this application. In the drawings:

[0022] Figure 1 This is a schematic diagram of the structure of the present invention;

[0023] Figure 2 This is a data distribution diagram showing the removal rate of hexavalent chromium ions according to the present invention;

[0024] Figure 3This is a data distribution diagram showing the removal rate of sulfadiazine according to the present invention;

[0025] Figure 4 This is a data distribution diagram of the generated voltage in this invention;

[0026] Figure 5 This is a data distribution diagram of the chemical oxygen demand removal rate according to the present invention;

[0027] Figure 6 This is a data distribution diagram of the total phosphorus removal rate according to the present invention;

[0028] Figure 7 This is a data distribution diagram of the total nitrogen removal rate according to the present invention.

[0029] In the diagram: 1. Outer shell; 2. Inlet; 3. Outlet; 4. Plants; 5. Gravel layer; 6. First soil layer; 7. Anode graphite particles; 8. Anode carbon felt and titanium wire composite electrode; 9. Cathode graphite particles; 10. Cathode carbon felt and titanium wire composite electrode; 11. Second soil layer; 12. Cathode wire; 13. Anode wire; 14. Voltage workstation; 15. Variable resistor. Detailed Implementation

[0030] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0031] To make the above-mentioned objects, features and advantages of the present invention more apparent and understandable, the present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0032] Reference Figure 1-7 This invention provides a novel bio-optocoupler device, comprising:

[0033] The outer casing 1 has a water inlet 2 at the bottom and a water outlet 3 at the top.

[0034] An artificial wetland unit includes, from bottom to top, a diversion layer and an intermediate matrix layer laid inside the outer shell 1, with plants 4 planted in the intermediate matrix layer; the inlet 2 is located at the bottom of one side of the diversion layer.

[0035] The plant 4 used in this embodiment is a canna lily;

[0036] The microbial fuel cell unit includes an anode layer and a cathode layer, which are electrically connected by an external circuit. The anode layer is located between the flow distribution layer and the intermediate matrix layer, and the cathode layer is located above the intermediate matrix layer. The top of the plant 4 penetrates the cathode layer and extends out of the outer shell 1, and the water outlet 3 is located above the cathode layer.

[0037] The outer shell 1 is made of plexiglass. Aluminum foil is used to wrap the outer shell 1 to prevent light from shining on the middle matrix layer. The aluminum foil is used to prevent interference from antibiotic photodegradation and to simulate the light-free environment of the matrix in natural wetlands.

[0038] Artificially prepared wastewater containing antibiotics and heavy metal ions, meeting the secondary wastewater discharge standards, is introduced into the outer shell 1 through inlet 2. The wastewater sequentially passes through a diversion layer, an anode layer, an intermediate matrix layer, and a cathode layer, finally flowing out through outlet 3. The diversion layer, intermediate matrix layer, and plants 4 remove common pollutants from the wastewater. The intermediate matrix layer is rich in electrogenic microorganisms, and the growth of plants simultaneously stimulates the growth of electrogenic microorganisms in the intermediate matrix. Organic pollutants in the wastewater provide carbon sources for the microorganisms, thus avoiding the need for additional microbial nutrient solutions to maintain the electrogenic microorganisms. The electrogenic microorganisms attach to the anode and cathode layers. The electrogenic microorganisms in and around the anode layer oxidize organic pollutants and generate electrons. These electrons travel through the external circuit to the cathode layer to reduce heavy metals, thereby removing heavy metal ions, antibiotics, and other complex pollutants from the wastewater, completing both the pollutant removal and electrogenic processes. This invention couples a biofuel cell unit and an artificial wetland unit, integrating the advantages of both. It can not only remove common pollutants, but also remove complex pollutants such as heavy metal ions and antibiotics, thereby improving the pollutant removal capacity. At the same time, it improves the utilization rate of electrogenic microorganisms in the artificial wetland, thereby improving the power generation capacity of the microbial fuel cell and achieving a more economical input-output ratio.

[0039] The scheme is further optimized. The diversion layer includes a gravel layer 5 and a first soil layer 6. The gravel layer 5 is laid at the bottom of the outer shell 1, and the first soil layer 6 is laid between the gravel layer 5 and the anode layer. The inlet 2 is located at the bottom of one side of the gravel layer 5.

[0040] Wastewater flows into the gravel layer 5 from the inlet 2. The gravel layer 5 can reduce the flow rate of the wastewater and disperse the flow direction. The first soil layer 6 further reduces the flow rate, so that the water flows into the anode layer evenly and slowly, which increases the reaction time of the wastewater in the device and improves the removal effect of pollutants in the wastewater. Moreover, the use of gravel layer 5 and first soil layer 6 for water distribution is inexpensive and occupies less space.

[0041] The scheme is further optimized. The anode layer includes several anode graphite particles 7 and anode carbon felt and titanium wire composite electrode 8. The anode carbon felt and titanium wire composite electrode 8 is laid between several anode graphite particles 7. Several anode graphite particles 7 are laid between the first soil layer 6 and the intermediate matrix layer.

[0042] The cathode layer includes several cathode graphite particles 9 and cathode carbon felt and titanium wire composite electrode 10. The cathode carbon felt and titanium wire composite electrode 10 is laid between several cathode graphite particles 9. Several cathode graphite particles 9 are laid on top of the intermediate matrix layer. Anode carbon felt and titanium wire composite electrode 8 and cathode carbon felt and titanium wire composite electrode 10 are electrically connected through an external circuit. Several cathode graphite particles 9 and cathode carbon felt and titanium wire composite electrode 10 pass through the top of the plant 4. The water outlet 3 is located above several cathode graphite particles 9.

[0043] Using a composite electrode of carbon felt and titanium wire as the anode and cathode can increase the contact area between the electrode and water pollutants and electrogenic microorganisms. The graphite particles expand the specific surface area of ​​the actual electrode, allowing more microorganisms to attach to the electrode, thereby improving power generation efficiency. Moreover, the cathode graphite particles 9 and the anode graphite particles 7 exist in particle form and will not hinder the growth of the plant 4.

[0044] The scheme is further optimized so that the intermediate matrix layer includes a second soil layer 11, which is located between a number of anode graphite particles 7 and a number of cathode graphite particles 9, and the plant 4 is planted in the second soil layer 11.

[0045] The second soil layer 11 serves as a growth substrate for plants 4, providing a more natural growth environment for plants 4 and microorganisms, which is conducive to their growth. The natural soil substrate allows for a wider range of plant 4 options and a longer operating time, thus improving the removal efficiency of pollutants in wastewater.

[0046] In a further optimized design, the external circuit includes a cathode wire 12 and an anode wire 13. The anode wire 13 is electrically connected to the anode carbon felt and titanium wire composite electrode 8, and the cathode wire 12 is electrically connected to the cathode carbon felt and titanium wire composite electrode 10. Both the cathode wire 12 and the anode wire 13 extend outside the outer casing 1 and are electrically connected to a voltage workstation 14. A variable resistor 15 is electrically connected between the anode wire 13 and the cathode wire 12, and the variable resistor 15 is connected in parallel with the voltage workstation 14. The parallel connection of the voltage workstation 14 and the variable resistor 15 can measure the internal resistance of the device. In this embodiment, the cathode wire 12 and the anode wire 13 are inert copper wires.

[0047] The scheme was further optimized so that the four roots of the plant penetrated the second soil layer 11, several anode graphite particles 7, the anode carbon felt and titanium wire composite electrode 8, the first soil layer 6, and extended into the gravel layer 5.

[0048] The roots of plant 4 carry oxygen to all levels, enhancing the removal of pollutants and the efficiency of power generation. At the same time, the roots of plant 4 enhance the stability of each level of the device.

[0049] Further optimization of the scheme: the thickness of the second soil layer 11 is 10-20cm, the thickness of the first soil layer 6 is 1-4cm, the thickness of a number of anode graphite particles 7 is 2-6cm, the thickness of a number of cathode graphite particles 9 is 2-6cm, and the thickness of the gravel layer 5 is 1-5cm.

[0050] The thickness of each filler layer can be adjusted according to the pollutants that need to be removed. If more reducing substances need to be removed, the thickness of the anode graphite particles 7 can be increased. If more oxidizing substances need to be removed, the thickness of the cathode graphite particles 9 can be increased. If more common pollutants need to be removed by the intermediate matrix layer and plants 4, the thickness of the second soil layer 11 can be increased.

[0051] Further optimization of the scheme resulted in gravel particles of 2-8mm in gravel layer 5.

[0052] Further optimization of the scheme resulted in cathode graphite particles 9 and anode graphite particles 7 having a particle size of 3-8 mm.

[0053] To further optimize the scheme, nylon cloth is laid between the gravel layer 5 and the first soil layer 6, between the first soil layer 6 and several anode graphite particles 7, between several anode graphite particles 7 and the second soil layer 11, and between the second soil layer 11 and several cathode graphite particles 9; thereby increasing the stability of each layer.

[0054] A certain concentration of sulfadiazine antibiotic and hexavalent chromium heavy metal ions are added to artificially prepared secondary wastewater. The prepared wastewater is then pumped into the outer casing 1 through inlet 2 via an external peristaltic pump (not shown in the figure), and finally flows out through outlet 3 into a circulating water tank (not shown in the figure) for recirculation. The operating cycle is about 15 days. Within 15 days, the removal rate of hexavalent chromium ions can reach 95%; the removal rate of sulfadiazine can reach 80%; the power generation voltage can reach 700mV; the removal rate of chemical oxygen demand (COD) can reach 90%; the removal rate of total phosphorus (TP) can reach 95%; the removal rate of total nitrogen (TN) can reach 95%; and the plants 4 can grow stably.

[0055] In the description of this invention, it should be understood that the terms "longitudinal", "lateral", "up", "down", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing this invention, and are not intended to indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this invention.

[0056] The embodiments described above are merely preferred embodiments of the present invention and are not intended to limit the scope of the present invention. Various modifications and improvements made by those skilled in the art to the technical solutions of the present invention without departing from the spirit of the present invention should fall within the protection scope defined by the claims of the present invention.

Claims

1. A bio-optocoupler, characterized in that, include: The outer casing (1) has a water inlet (2) at the bottom and a water outlet (3) at the top. An artificial wetland unit includes a diversion layer and an intermediate matrix layer laid sequentially from bottom to top inside the outer shell (1), wherein plants (4) are planted in the intermediate matrix layer; the inlet (2) is located at the bottom of one side of the diversion layer; The microbial fuel cell unit includes an anode layer and a cathode layer. The anode layer and the cathode layer are electrically connected by an external circuit. The anode layer is located between the shunt layer and the intermediate matrix layer. The cathode layer is located above the intermediate matrix layer. The top of the plant (4) penetrates the cathode layer and extends out of the outer shell (1). The water outlet (3) is located above the cathode layer. The diversion layer includes a gravel layer (5) and a first soil layer (6). The gravel layer (5) is laid at the bottom of the outer shell (1), and the first soil layer (6) is laid between the gravel layer (5) and the anode layer. The inlet (2) is located at the bottom of one side of the gravel layer (5). The anode layer includes a plurality of anode graphite particles (7) and an anode carbon felt and titanium wire composite electrode (8). The anode carbon felt and titanium wire composite electrode (8) is laid between the plurality of anode graphite particles (7). The plurality of anode graphite particles (7) are laid between the first soil layer (6) and the intermediate matrix layer. The cathode layer includes a plurality of cathode graphite particles (9) and a cathode carbon felt and titanium wire composite electrode (10). The cathode carbon felt and titanium wire composite electrode (10) is laid between the plurality of cathode graphite particles (9). The plurality of cathode graphite particles (9) are laid above the intermediate matrix layer. The anode carbon felt and titanium wire composite electrode (8) and the cathode carbon felt and titanium wire composite electrode (10) are electrically connected through the external circuit. The top of the plant (4) passes through the plurality of cathode graphite particles (9) and the cathode carbon felt and titanium wire composite electrode (10). The water outlet (3) is located above the plurality of cathode graphite particles (9).

2. The bio-optocoupler device according to claim 1, characterized in that: The intermediate matrix layer includes a second soil layer (11) located between a plurality of anode graphite particles (7) and a plurality of cathode graphite particles (9), and the plant (4) is planted in the second soil layer (11).

3. The bio-optocoupler device according to claim 1, characterized in that: The external circuit includes a cathode wire (12) and an anode wire (13). The anode wire (13) is electrically connected to the anode carbon felt and titanium wire composite electrode (8). The cathode wire (12) is electrically connected to the cathode carbon felt and titanium wire composite electrode (10). Both the cathode wire (12) and the anode wire (13) extend out of the outer shell (1) and are electrically connected to a voltage workstation (14). A variable resistor (15) is electrically connected between the anode wire (13) and the cathode wire (12). The variable resistor (15) is connected in parallel with the voltage workstation (14).

4. The bio-optocoupler device according to claim 2, characterized in that: The roots of the plant (4) penetrate the second soil layer (11), several of the anode graphite particles (7), the anode carbon felt and titanium wire composite electrode (8), and the first soil layer (6) in sequence, and extend into the gravel layer (5).

5. The bio-optocoupler device according to claim 2, characterized in that: The second soil layer (11) has a thickness of 10-20cm, the first soil layer (6) has a thickness of 1-4cm, the anode graphite particles (7) have a thickness of 2-6cm, the cathode graphite particles (9) have a thickness of 2-6cm, and the gravel layer (5) has a thickness of 1-5cm.

6. The bio-optocoupler device according to claim 1, characterized in that: The gravel particle size of the gravel layer (5) is 2-8 mm.

7. The bio-optocoupler device according to claim 1, characterized in that: The particle size of the cathode graphite particles (9) and the anode graphite particles (7) is 3-8 mm.

8. The bio-optocoupler device according to claim 2, characterized in that: Nylon cloth is laid between the gravel layer (5) and the first soil layer (6), between the first soil layer (6) and a plurality of anode graphite particles (7), between a plurality of anode graphite particles (7) and the second soil layer (11), and between the second soil layer (11) and a plurality of cathode graphite particles (9).

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