A photosynthetic algal microbial fuel cell structure
The dual-chamber photosynthetic algae microbial fuel cell solves the problems of low power generation efficiency and high operating costs by using the anode to catalyze the degradation of organic matter and the cathode to release oxygen through photosynthesis, thus achieving efficient power recovery and pollutant removal.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- NAVAL UNIV OF ENG PLA
- Filing Date
- 2025-04-03
- Publication Date
- 2026-08-04
AI Technical Summary
Existing microbial fuel cells suffer from low power generation efficiency of electrogenic bacteria, high operating costs due to the need for continuous aeration at the cathode, and a decrease in the photosynthetic rate of microalgae in the cathode chamber.
The photosynthetic algae microbial fuel cell adopts a dual-chamber structure. The anode chamber uses anaerobic activated sludge to catalyze the degradation of organic matter, while the cathode chamber cultivates microalgae to release oxygen through photosynthesis. The proton exchange membrane only allows protons to pass through, and the microalgae use the cations accumulated in the cathode chamber as a nutrient source to achieve efficient power generation and pollutant removal.
It improves the electrode reaction rate, reduces operating costs, achieves efficient pollutant removal and energy recovery, reduces greenhouse gas emissions, and has high tolerance and stability.
Smart Images
Figure CN224595513U_ABST
Abstract
Description
Technical Field
[0001] This invention belongs to, but is not limited to, the field of microbial fuel cell technology, and particularly relates to a structure of photosynthetic algae microbial fuel cell. Background Technology
[0002] A microbial fuel cell (MFC) is a bioelectrochemical clean energy device that utilizes microorganisms as catalysts to simultaneously purify wastewater and generate electricity. It typically consists of an anode chamber, a cathode chamber, separating materials, and an external circuit. Electrogenic bacteria oxidize and decompose organic matter in an anaerobic environment at the anode, producing electrons and protons. These electrons and protons are transferred to the cathode via the external circuit and a proton exchange membrane, respectively. At the cathode, in an aerobic environment, electrons react with electron acceptors such as O2, nitrates, and permanganates, resulting in a reduction reaction. The externally loaded circuit receives continuous current and power output during this process. However, most electrogenic bacteria have low power generation efficiency, typically requiring increased feed rates or a larger number of electron acceptors to increase energy output. MFC cathodes often use O2 as the electron acceptor, necessitating continuous aeration during operation, leading to high operating costs.
[0003] Microalgae, rich in chlorophyll a, can absorb nitrogen, phosphorus, and organic matter from wastewater. They utilize the CO2 released by the respiration of electrogenic bacteria for photosynthesis, while nitrogen and phosphorus are converted into biomass. The O2 produced by microalgae can act as an electron acceptor. Applying microalgae to MFCs and constructing a symbiotic system with electrogenic bacteria for material exchange can improve the MFC's tolerance to the external environment and reduce wastewater treatment costs, showing great promise for future applications.
[0004] Based on their operational characteristics, devices combining algal symbiotic systems with microfuel cells (MFCs) are called photosynthetic algal microbial fuel cells (PAMFCs). In PAMFCs, the synergistic effect of microalgae and electrogenic bacteria can improve the utilization rate of microalgae while achieving wastewater treatment and energy recovery, effectively solving the problem of continuous oxygen supply from the cathode.
[0005] In recent years, the use of PAMFCs with different configurations to treat wastewater has become a research frontier in the field of water treatment, but there is almost no introduction to PAMFC configurations. Summary of the Invention
[0006] To address the problems existing in the prior art, this utility model provides a structure for a photosynthetic algae microbial fuel cell.
[0007] This invention is implemented as follows: a photosynthetic algae microbial fuel cell structure, comprising a battery base, an anode electrode bottle, a cathode electrode bottle, two liquid storage tanks, a development board, and a display screen; the battery base is fixed to the electrode bottles and liquid storage tanks via a base; the caps of the anode and cathode electrode bottles have multiple small holes, and the cathode electrode bottle has two water passages on its side, with the lower water passage connected to one liquid storage tank via a pipe, and the upper water passage connected to the other liquid storage tank via a pipe; the anode and cathode electrode bottles are connected via a frosted bottle connector; the development board and display screen are fixed on the battery base, and their wiring is arranged inside the battery base.
[0008] Furthermore, the multiple small holes on the bottle cap facilitate the insertion of the conductive rod, and the end of the conductive rod has a clamping lock to facilitate the fixation of the anode electrode film.
[0009] Furthermore, the bottle cap is made of frosted glass, which facilitates disassembly for later replacement of the electrolyte and electrodes.
[0010] Furthermore, the bottle interface is detachable, making it easy to replace the proton exchange membrane installed on it.
[0011] Based on the above technical solutions and the technical problems solved, the advantages and positive effects of the technical solution to be protected by this utility model are as follows:
[0012] The system provided by this invention adopts a dual-chamber structure, consisting of an anode chamber and a cathode chamber. The anode chamber utilizes anaerobic activated sludge as inoculum, where electrogenic bacteria catalyze the degradation of organic matter and generate electrons under anaerobic conditions without light, while simultaneously undergoing denitrification. The cathode chamber cultivates microalgae, which, under illumination, utilize the input carbon dioxide to release oxygen through photosynthesis, increasing the cathode redox rate and enhancing the battery's reaction efficiency. Furthermore, because the proton exchange membrane (PEM) of the dual-chamber PAMFC only allows protons to pass through, other cations (such as Na+, K+, and NH4+) accumulate in the cathode chamber. Microalgae can utilize these ions as a nutrient source, increasing their growth rate, thereby achieving the dual effects of efficient electricity generation and pollutant removal.
[0013] Compared to traditional PAMFCs, the introduction of microalgae biocathodes eliminates the need for additional aeration, significantly reducing operating costs while simultaneously increasing electrode reaction rates. Microalgae photosynthesis not only promotes redox reaction rates but also reduces carbon dioxide levels in the environment, contributing to greenhouse gas reduction. Under optimal operating conditions (27 °C, light / dark cycle 12 h / 12 h), the system achieves a 95.5% removal rate for NH4+ N with a voltage output of 350 mV. Even when the NH4+ N concentration in the cathode influent increases to 90 mg / L, it still maintains an 83% removal rate, demonstrating extremely high tolerance and stability.
[0014] In recent years, immobilized microalgae technology has been widely used in PAMFC cathodes to construct microbial carbon capture batteries (MCCs) to reduce the decline in photosynthetic rate caused by microalgae attaching to the cathode chamber walls. This technology, by immobilizing microalgae on a special carrier, ensures their uniform distribution within the cathode region, optimizing light utilization efficiency and improving the overall system power density and coulombic efficiency. Microalgae-based PAMFC cathodes not only have broad application prospects in energy recovery but also provide an efficient and low-cost solution for wastewater treatment and carbon capture. Attached Figure Description
[0015] Figure 1 This is a schematic diagram of the structure of a photosynthetic algae microbial fuel cell provided in an embodiment of this utility model;
[0016] Figure 2 This is a schematic diagram of the liquid storage tank provided in an embodiment of the present utility model;
[0017] Figure 3 This is a schematic diagram of the cathode electrode bottle provided in an embodiment of this utility model;
[0018] Figure 4 This is a schematic diagram of the anode electrode bottle provided in an embodiment of the present invention;
[0019] Figure 5 This is a schematic diagram of the bottle connector provided in an embodiment of the present invention;
[0020] Figure 6 This is a schematic diagram of the electrode bottle cap provided in an embodiment of the present utility model;
[0021] Figure 7 This is a schematic diagram of the electrode post provided in an embodiment of the present invention;
[0022] Figure 8 This is a fastener provided in the embodiments of this utility model;
[0023] Figure 9 This is the electrode film provided in the embodiments of this utility model;
[0024] Figure 10 This is a schematic diagram provided by an embodiment of the present utility model. Figure 10 (a) is sCOD, Figure 10 (b) is NH4⁺-N, Figure 10 (c) are NO⁻-N and NO⁻-N. Figure 10 (d) is TN. Figure 10 (e) is PO4³⁻-P, Figure 10 (f) shows the concentration changes of SO4²⁻S in the effluent from the anode and cathode of the PMFC;
[0025] In the diagram: 1. Storage tank; 2. Battery holder; 3. Conduit; 4. Cathode electrode bottle; 5. Anode electrode bottle;
[0026] 6. Electrode cap; 7. Electrode post; 8. Fastener; 9. Electrode film; 10. Bottle connector. Detailed Implementation
[0027] To make the objectives, technical solutions, and advantages of this utility model clearer, the following detailed description is provided in conjunction with embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the scope of this utility model.
[0028] like Figure 1 , Figure 7 As shown, this utility model embodiment provides a photosynthetic algae microbial fuel cell structure, which consists of a battery base 2, an anode electrode bottle 5, a cathode electrode bottle 4, an electrode column 7, and two liquid storage tanks; the battery base 2 is a base that supports the main body of the battery and is fixed to the electrode bottle and liquid storage tanks through the base.
[0029] like Figure 2 , Figure 6 , Figure 8 The electrode bottle is divided into two parts: anode and cathode electrode bottles. The anode electrode bottle 5 acts as the battery anode. Both the anode electrode bottle 5 and the cathode electrode bottle 4 have multiple small holes on their caps for easy insertion of conductive rods. The ends of the conductive rods are fasteners 8 for securing the anode and cathode electrode films. The electrode bottle cap 6 is made of frosted glass for easy disassembly to replace the electrolyte and electrodes. The cathode electrode bottle 4 has two water inlets on its side. The lower water inlet is connected to a storage tank via a pipe, and the upper water inlet is connected to another storage tank via a pipe. The wastewater to be treated enters the cathode bottle through the lower side inlet and flows out of the cathode bottle through the upper side inlet after treatment.
[0030] like Figure 3 , Figure 4 , Figure 5 The storage tank and the cathode electrode bottle 4 are connected by a pipe. The anode electrode bottle 5 and the cathode electrode bottle 4 are connected by a frosted bottle connector 10. The bottle interface is detachable, which makes it easy to replace the proton membrane installed on it.
[0031] When in operation, the electrode films are installed in the anode and cathode electrode bottles 5, the required electrolyte is filled into the anode bottle, and the conductive rods of the anode and cathode electrode bottles 5 are connected by wires. The wastewater to be treated flows from the storage tank into the cathode bottle, and the battery starts to work.
[0032] like Figure 9The photosynthetic algae microbial fuel cell consists of an anode electrode bottle 5, a cathode electrode bottle 4, a battery holder 2, a storage tank, and a piping system. Before operation, electrode films 9 are first installed in the anode electrode bottle 5 and the cathode electrode bottle 4, ensuring that the electrode films are fixed in the small holes of the electrode bottle caps. The anode and cathode electrodes are then secured using the clamping latches of conductive rods. After installation, a specific electrolyte, such as a nutrient solution rich in photosynthetic algae, is added to the anode electrode bottle 5 to promote electron transfer and energy conversion by the microorganisms.
[0033] Microorganisms (such as photosynthetic bacteria, cyanobacteria, or other anaerobic bacteria) inside the anode electrode bottle 5 release electrons and protons when decomposing organic matter (such as carbon sources in wastewater). These electrons are captured by the anode and transmitted to the external circuit through the conductive rod, thus forming an electric current. At the same time, the protons (H⁺) produced during the microbial decomposition process migrate to the cathode side through the proton exchange membrane installed between the anode and cathode electrode bottles 4, thereby maintaining charge balance.
[0034] In cathode electrode bottle 4, a storage tank connected by a pipe continuously supplies wastewater. The oxygen or other oxidants contained in the wastewater undergo a redox reaction at the cathode. Protons pass through the proton exchange membrane into the cathode and combine with electrons transferred from the external circuit, ultimately forming water or other reaction products, thus purifying the wastewater. For example, in an oxygen-rich environment, the cathode reaction can be represented as:
[0035]
[0036] This formula explains that each oxygen molecule in the cathode combines with four protons from the anode and four electrons from the external circuit to produce two water molecules.
[0037] This process can generate electricity and reduce the concentration of pollutants in wastewater, achieving the dual functions of simultaneous power generation and wastewater treatment.
[0038] Through an external circuit, electrons are transferred from the anode to the cathode, forming a closed current that can be used to drive electronic devices or store energy. Simultaneously, wastewater continuously flows into the cathode bottle through the lower water inlet. After completing the oxidation-reduction reaction, the treated water flows out through the upper water inlet into the storage tank, achieving water circulation. Because the battery bottle interface features a detachable design, the proton exchange membrane and electrolyte can be easily replaced to maintain long-term stable operation. The entire system, through the combined action of biocatalysis at the anode and the oxidation-reduction reaction at the cathode, achieves the synergistic utilization of wastewater purification and renewable energy power generation.
[0039] Example 1: Photosynthetic algae microbial fuel cell system for urban wastewater treatment
[0040] 1. System Construction
[0041] This embodiment constructs an experimental device for urban wastewater treatment based on a photosynthetic algal microbial fuel cell (PMFC) structure. The system mainly consists of an anode electrode bottle, a cathode electrode bottle, a battery holder, two storage tanks, and connecting pipes, and employs carbon felt electrodes and Nafion 117 proton exchange membranes. Wastewater rich in cyanobacteria (such as Chlorella) and anaerobic microorganisms is inoculated into the anode electrode bottle, while an oxygen-enriched aqueous solution is circulated into the cathode electrode bottle to promote the oxidation reaction.
[0042] 2. Operation process
[0043] Anode reaction: Microorganisms inside the anode bottle decompose organic matter in the wastewater, releasing electrons and protons. Electrons are transferred to the external circuit via the carbon felt anode, while protons pass through the proton exchange membrane into the cathode electrode bottle.
[0044] Cathode reaction: Dissolved oxygen (O2) in the cathode bottle acts as an electron acceptor, combining with H⁺ that migrates through the proton exchange membrane to form H₂O, while releasing electrical energy.
[0045] Current output: The measured battery voltage is between 0.45V and 0.6V, with a maximum output power density of 150mW / m².
[0046] Wastewater purification: After 72 hours of operation, the COD (chemical oxygen demand) removal rate in the anode bottle reached 80%, and the ammonia nitrogen removal rate reached 60%.
[0047] 3. Results and Analysis
[0048] This photosynthetic algae microbial fuel cell system not only generates considerable electrical energy, but also degrades organic pollutants in urban sewage. It can be applied to small-scale sewage treatment facilities to reduce the energy consumption of traditional sewage treatment.
[0049] Example 2: Photosynthetic algae microbial fuel cell system for treating aquaculture wastewater
[0050] 1. System Construction
[0051] This embodiment utilizes photosynthetic algae microbial fuel cell technology to treat aquaculture wastewater. The system structure is similar to that of Embodiment 1, but the anode microbial community is optimized by using a mixed community of red algae, diatoms, and anaerobic microorganisms to enhance electron transfer capabilities. The electrolyte in the anode electrode bottle is a culture medium rich in aquaculture wastewater, while the cathode bottle uses aerated water to increase oxygen supply.
[0052] 2. Operation process
[0053] Anode biocatalysis: Microorganisms in the anode bottle decompose proteins, ammonia nitrogen and organic matter in aquaculture wastewater. Electrons enter the external circuit through the carbon felt anode, and protons migrate to the cathode bottle through the proton exchange membrane.
[0054] Cathode redox: Oxygen (O2) in the cathode bottle combines with H⁺ to complete the electron acceptor reaction and form H₂O.
[0055] Power output: Measurements show that the battery voltage is between 0.38V and 0.55V, with a maximum power density of 120mW / m².
[0056] Water quality improvement: After 5 days of continuous operation, the COD removal rate was 85%, the ammonia nitrogen removal rate was 70%, dissolved oxygen increased, and the water quality was significantly improved.
[0057] 3. Results and Analysis
[0058] This photosynthetic algae microbial fuel cell system is suitable for treating aquaculture wastewater, effectively reducing ammonia nitrogen content and lowering the risk of eutrophication. It also generates a certain amount of electricity, which can be used to power low-power sensors and improve the energy self-sufficiency of aquaculture farms.
[0059] I. Specific application areas or related products of this invention. 1. Wastewater treatment and energy recovery simultaneous system.
[0060] Application scenarios: Municipal / industrial wastewater treatment plants, rural decentralized wastewater treatment stations
[0061] Example: The PAMFC device of this invention is integrated into a wastewater aeration tank. Algae (such as Chlorella) are co-cultured with electrochemically active bacteria. The anode layer of the battery utilizes organic matter in the wastewater (COD 2000-5000 mg / L) as fuel for the bacteria; while the algae, acting as the cathode layer, release oxygen through photosynthesis as an electron acceptor, and simultaneously absorb nitrogen and phosphorus from the wastewater (TP removal rate >85%, TN removal rate >70%). This structure simultaneously achieves the dual objectives of wastewater purification (effluent COD <50 mg / L) and biomass power generation (power density up to 12 W / m³).
[0062] 2. Self-powered ecological floating island
[0063] Application scenarios: Eutrophication control of lakes, restoration of landscape water bodies
[0064] Example: The floating island module incorporates a layered PAMFC structure. The upper layer utilizes an algal membrane (a mixture of cyanobacteria and green algae) to absorb sunlight and CO2, suppressing harmful algal blooms; the lower layer utilizes sediment microorganisms to decompose organic matter in the bottom sediment to generate electricity. A single module generates 0.5-1.2 kWh per day, enough to power a water quality monitoring sensor (requiring <10 W of power). II. Evidence related to the technical effects obtained from the embodiments of this invention.
[0065] The table below lists the current application status of dual-chamber PAMFCs in wastewater treatment. It can be seen that, except for dye wastewater, dual-chamber PAMFCs exhibit good COD removal efficiency for various types of wastewater. This is due to the contamination of the anode by azo dyes and their degradation products.
[0066]
[0067] Figure 10 This indicates that the dual-chamber PMFC can achieve a removal efficiency of up to 93.2% for dissolved chemical oxygen demand (sCOD), 95.9% for ammonia nitrogen (NH4+-N), 95.1% for total nitrogen (TN), and 82.7% for phosphate (PO43−-P), as well as a maximum power density of 466.9 mW per cubic meter.
[0068] In the description of this utility model, unless otherwise stated, "a plurality of" means two or more; the terms "upper," "lower," "left," "right," "inner," "outer," "front end," "rear end," "head," "tail," 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 utility model and simplifying the description, and do not 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 utility model. In addition, the terms "first," "second," "third," etc., are used for descriptive purposes only and should not be construed as indicating or implying relative importance.
[0069] The above description is only a specific embodiment of this utility model, but the protection scope of this utility model is not limited thereto. Any modifications, equivalent substitutions and improvements made by those skilled in the art within the technical scope disclosed in this utility model, and within the spirit and principles of this utility model, should be included within the protection scope of this utility model.
Claims
1. A photosynthetic algal microbial fuel cell structure, characterized by, It consists of a battery holder, an anode electrode bottle, a cathode electrode bottle, and two liquid storage tanks. The battery holder is fixed to the electrode bottles and liquid storage tanks via a base. The caps of the anode and cathode electrode bottles have multiple small holes. The cathode electrode bottle has two water passages on its side. The lower water passage is connected to one liquid storage tank via a pipe, and the upper water passage is connected to the other liquid storage tank via a pipe. The anode and cathode electrode bottles are connected via a frosted bottle connector.
2. The photosynthetic algal microbial fuel cell structure of claim 1, wherein, The bottle cap has multiple small holes for easy insertion of the conductive rod, and the end of the conductive rod has a clamping buckle to facilitate fixing the anode electrode film.
3. The photosynthetic algal microbial fuel cell structure of claim 1, wherein, The bottle cap is made of frosted glass, which makes it easy to disassemble later to replace the electrolyte and electrodes.
4. The photosynthetic algal microbial fuel cell structure of claim 1, wherein, The bottle interface is detachable, making it easy to replace the proton exchange membrane installed on it.