System and method for synergistically degrading antibiotic by microbe fuel cell driven photoelectrocatalysis

Abstract

The application provides a system for photoelectrocatalytic synergistic degradation of antibiotics driven by a microbial fuel cell, comprising a photoelectrocatalytic device and a microbial fuel cell system. The application limits the encapsulation of a light anode+MFC self-driving+in-situ H2O2 production" synergistic system; a green self-driven energy system is constructed: a double-chamber MFC is used to replace an external bias, electricity is generated by using microorganisms to degrade photoelectrocatalytic intermediates, a stable voltage (0.6~0.8V) is output, and the demand of photoelectrocatalysis is met; and no fossil energy is input throughout the process.

Description

Technical Field

[0001] This application belongs to the field of antibiotic degradation technology, specifically relating to a system and method for the photoelectrocatalytic synergistic degradation of antibiotics driven by microbial fuel cells. Background Technology

[0002] Existing antibiotic treatment technologies have significant limitations: adsorption methods only achieve pollutant transfer, and adsorbent regeneration is difficult; chemical methods such as Fenton oxidation and ozone oxidation have high energy consumption and highly toxic byproducts; biological methods have low degradation efficiency (usually less than 40%) due to the antibacterial properties of antibiotics; and traditional electrochemical methods require continuous input of electrical energy, resulting in high operating costs.

[0003] Photocatalysis, as a synergistic technology of photocatalysis and electrocatalysis, has become a research hotspot due to its advantages such as mild reaction conditions (room temperature and pressure) and less secondary pollution.

[0004] To enhance degradation efficiency, the introduction of H2O2 can improve oxidation capacity by generating hydroxyl radicals (·OH). However, the cost of purchasing H2O2 is high and the production process is highly polluting. Recent studies have shown that carbon-based gas diffusion electrodes (GDEs) can produce H2O2 in situ through a two-electron oxygen reduction reaction, but this requires an external voltage (0.5~1.0V) and results in significant carbon emissions when relying on thermal power generation.

[0005] Microbial fuel cells (MFCs), as a novel bioelectrochemical technology, can generate electricity (output voltage 0.3~0.6V) while degrading pollutants. However, when used alone to treat antibiotics, the pollutant removal rate is less than 30% due to the toxic inhibitory effect of antibiotics on microorganisms, and the output voltage is unstable. Existing photocatalysis-MFC coupling technologies mostly adopt the "anodic anaerobic + photocatalysis" mode. The anaerobic environment leads to insufficient dissolved oxygen required for photocatalysis, resulting in a decrease of more than 60% in ·OH generation, which severely limits the synergistic efficiency.

[0006] Photocatalysis-MFC coupling system: This system modifies the anode or cathode of an MFC with photocatalytic materials (such as TiO2) to form a synergistic system of "photocatalytic pretreatment + biodegradation". For example, one scheme loads Ag3PO4 onto the MFC anode, uses photocatalytic pretreatment to reduce antibiotic toxicity, and then performs microbial degradation. The system achieves a 75% degradation rate for tetracycline. However, due to the anaerobic environment of the anode (dissolved oxygen < 0.5 mg / L), the photocatalytic efficiency is only 30% of that under aerobic conditions, and the output voltage fluctuates greatly (0.2~0.4V), making it impossible to stably drive the photoelectrocatalytic reaction. Although the above schemes improve the degradation efficiency to some extent, they do not solve the core problems such as "insufficient photoanode activity, bias voltage dependence on fossil fuels, in-situ clean generation of H2O2, and oxygen environment limitations of the coupling system".

[0007] Based on the above, the existing technology has the following drawbacks.

[0008] Performance defects of photoanode materials

[0009] Narrow spectral response range: TNAs only respond to ultraviolet light (sunlight accounts for < 5%), and the visible light utilization rate is < 10%; conventional bismuth-based modifications (such as Bi2WO6 / TNAs) have limited improvement in visible light absorption efficiency (only up to 30%) due to their aggregated structure.

[0010] Low charge transfer efficiency: Bismuth-based semiconductors are deposited only on the surface of TNAs, resulting in a small contact area with TiO2 (<10 μm). 2 High charge transfer resistance (>500Ω), photogenerated carrier recombination rate >60%, and quantum efficiency <15%.

[0011] Poor stability: bismuth-based materials loaded on the surface are prone to detachment (detachment rate > 40% after 5 cycles), leading to a sharp drop in activity and leaching of metal ions (such as Bi). 3+ Concentrations > 0.5 mg / L pose a risk of secondary pollution.

[0012] 2. The energy supply method is not green.

[0013] Traditional photoelectrocatalysis requires an external bias voltage (0.5~1.0V), and the electrical energy mainly comes from thermal power generation. It can process 1m³ of... 3 Wastewater carbon emissions > 1.2 kg CO2;

[0014] The GDE cathode for electrochemical in-situ H2O2 production requires an additional power supply (0.6~1.2V), further increasing energy consumption (total energy consumption > 1.0kWh / m). 3 ).

[0015] 3. Limited application of H2O2

[0016] Purchasing H2O2 externally is costly (for processing 1m³ of H2O2). 3 Wastewater treatment costs 1.5 to 3 yuan, and there is a risk of explosion during storage and transportation;

[0017] The anthraquinone process for producing H2O2 generates 500 tons of organic waste per 10,000 tons, which does not meet the requirements of green processes. Existing in-situ H2O2 production technologies (such as GDE cathodes) have large yield fluctuations (10~30 mg / h) due to unstable bias voltage.

[0018] 4. Insufficient efficiency of microbial fuel cells

[0019] Toxicity inhibition: Antibiotics (such as norfloxacin concentration > 10 mg / L) lead to a 50% decrease in microbial activity and a pollutant removal rate of < 30%;

[0020] Low power generation capacity: output voltage < 0.5V, power density < 50mW / m 2 It cannot drive photoelectrocatalytic reactions.

[0021] Coupled systems have poor coordination

[0022] Oxygen environment conflict: Existing photocatalysis-MFC coupling is mostly anodic anaerobic, and the dissolved oxygen required for photocatalysis is insufficient (<0.5mg / L), resulting in a 60% decrease in ·OH generation;

[0023] Poor connection of intermediate products: The photocatalytic intermediate products (such as carboxylic acids) do not match the metabolic needs of microorganisms, resulting in low mineralization rate (TOC removal rate < 40%).

[0024] In view of the above, this application is hereby submitted. Summary of the Invention

[0025] To address one of the aforementioned technical deficiencies, this application provides a system and method for the photoelectrocatalytic synergistic degradation of antibiotics driven by a microbial fuel cell.

[0026] According to a first aspect of the embodiments of this application, a system for the photoelectrocatalytic synergistic degradation of antibiotics driven by a microbial fuel cell is provided, comprising:

[0027] A photoelectrocatalytic device includes a photoelectrocatalytic chamber and a photoanode and a carbon-based GDE cathode disposed within the photoelectrocatalytic chamber; the photoelectrocatalytic chamber is equipped with an aeration device for generating oxygen, which is located to the left of the GDE cathode and is used to fill the chamber with oxygen to generate hydrogen peroxide.

[0028] A microbial fuel cell system includes a bio-power generation chamber, which includes an anode chamber and a cathode chamber. The anode chamber is equipped with a carbon felt anode, and the cathode chamber is equipped with a platinum sheet cathode. The anode chamber and the cathode chamber are connected by a proton exchange membrane.

[0029] The photoanode is electrically connected to the platinum cathode via an external circuit; the carbon-based GDE cathode via an external circuit with a series resistor is electrically connected to the carbon felt anode.

[0030] Preferably, the photoanode is a visible light responsive composite photoanode material, which includes: a TiO2 nanotube array, a bismuth-based semiconductor confined within the TiO2 nanotubes, and bismuth nanoparticles attached to the surface of the bismuth-based semiconductor.

[0031] Preferably, the inner diameter of the TiO2 nanotube is 50~80nm and the tube length is 1~2μm;

[0032] The bismuth-based semiconductor has a particle size of 5-10 nm; the bismuth-based semiconductor has an in-tube coverage of >80%;

[0033] The bismuth nanoparticles have a particle size of 3-5 nm.

[0034] Preferably, the carbon-based GDE cathode is a nitrogen-doped porous carbon catalyst.

[0035] The carbon felt anode is a carbon felt enriched with electrogenic microorganisms, prepared by inoculating activated sludge from an urban wastewater treatment plant and acclimating it to antibiotics for 30 days.

[0036] This application also provides a method for the photoelectrocatalytic synergistic degradation of antibiotics driven by a microbial fuel cell, using the above-described system; including:

[0037] The photocatalytic reactants are placed in the photoelectrocatalytic chamber;

[0038] The reaction solution after photoelectrocatalytic degradation was placed in a bioelectricity generation chamber, and the photoanode was electrically connected to the external circuit of the platinum cathode; the series resistor of the external circuit of the carbon-based GDE cathode was electrically connected to the carbon felt anode.

[0039] Starting device;

[0040] Provide visible light to the photoelectrocatalytic chamber;

[0041] Photocatalysis and electrocatalysis synergistic degradation of antibiotics;

[0042] Microbial fuel cell drive and biodegradation provide bias voltage to the photoelectrocatalytic chamber.

[0043] Preferably, the photocatalytic-electrocatalytic synergistic degradation of antibiotics specifically includes,

[0044] Visible light excites the photoanode to generate electron-hole pairs; electrons are transferred to the carbon-based GDE cathode via an external circuit, while holes remain at the photoanode to oxidize water and generate ·OH; electrons at the cathode undergo a two-electron reduction reaction with dissolved oxygen, and the in-situ generated H2O2, along with holes and ·OH, synergistically oxidizes antibiotics.

[0045] Preferably, the cathode electrons undergo a two-electron reduction reaction with dissolved oxygen as follows: O₂ + 2H₂ + +2e - →H2O2.

[0046] Preferably, the microbial fuel cell drive and biodegradation provide a bias voltage for the photoelectrocatalytic chamber, specifically,

[0047] The intermediate product of photoelectrocatalysis is degraded on the carbon felt anode, and the generated electrons are transferred to the external circuit through the carbon felt anode to provide bias voltage for the photoelectrocatalytic chamber; protons migrate to the photoelectrocatalytic chamber through the exchange membrane to participate in the H2O2 generation reaction and achieve charge balance.

[0048] Preferably, the bio-electricity generation chamber and the photoelectrocatalytic chamber are connected by a pipe, and the intermediate product flowing out of the photoelectrocatalytic chamber enters the anode chamber of the bio-electricity generation chamber as a substrate through the pipe, and is then degraded by the carbon felt anode.

[0049] Preferably, the reaction conditions are:

[0050] Visible light intensity set to 200~300mW / cm 2 Hydraulic retention time: 2-3 hours; Initial antibiotic concentration: 10-500 mg / L;

[0051] The series resistance of the external circuit is 10~50Ω;

[0052] The dissolved oxygen level in the photoelectrocatalytic chamber is maintained at 5-8 mg / L.

[0053] The beneficial effects of this application are:

[0054] 1. This invention relates to a confined encapsulated photoanode + MFC self-driven + in-situ H2O2 production synergistic system; constructing a green self-driven energy system: replacing the external bias voltage with a dual-chamber MFC, realizing electricity generation by microbial degradation of photoelectrocatalytic intermediates, outputting a stable voltage (0.6~0.8V) to meet the photoelectrocatalytic requirements; the entire process involves no fossil energy input, processing 1m³ of... 3 Wastewater carbon emissions are reduced to < 0.3 kg CO2 (75% lower than traditional technologies), achieving in-situ clean generation of H2O2: Based on a carbon-based GDE cathode, H2O2 production is achieved through a two-electron oxygen reduction reaction driven by MFC, resulting in a stable H2O2 yield of 50~80 mg / h.

[0055] Optimize the synergistic efficiency of the coupled system: Construct a dual-chamber structure of "aerobic photocatalytic chamber + anaerobic bio-electricity generation chamber" to achieve: maintained dissolved oxygen in the photocatalytic chamber at 5~8 mg / L, ensuring efficient ·OH generation (concentration > 10). -4 (mmol / L); photocatalytic intermediates (such as small molecule organic acids) are matched with microbial metabolism, thus improving TOC removal rate.

[0056] 2. This invention elucidates a cross-scale synergistic mechanism: revealing the synergistic relationship between photogenerated charge migration, MFC electron transport, and H2O2 activation, providing theoretical support for the treatment of similar recalcitrant pollutants. Attached Figure Description

[0057] The accompanying drawings, which are included to provide a further understanding of this application and form part of this application, illustrate exemplary embodiments and are used to explain this application, but do not constitute an undue limitation of this application. In the drawings:

[0058] Figure 1 This is a schematic diagram of a system for the photoelectrocatalytic synergistic degradation of antibiotics driven by a microbial fuel cell, as described in this application.

[0059] Figure 2 The figure shows the variation of SOUR of activated sludge in the photoelectrocatalytic coupled microbial fuel cell system and the traditional microbial fuel cell system.

[0060] Figure 3 This is a diagram showing the ROS generation in activated sludge during a biodegradation reactor.

[0061] Figure 4 The graph shows the degradation efficiency of levofloxacin and the total organic carbon removal efficiency of the traditional photoelectrocatalytic system compared with that of the present application.

[0062] Figure 5 The degradation product toxicity graph was assessed using TEST software. Detailed Implementation

[0063] To make the technical solutions and advantages of the embodiments of this application clearer, the exemplary embodiments of this application will be described in further detail below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of this application, and not an exhaustive list of all embodiments. It should be noted that, unless otherwise specified, the embodiments and features in the embodiments of this application can be combined with each other.

[0064] like Figures 1-5 As shown, according to a first aspect of an embodiment of this application, a system for the photoelectrocatalytic synergistic degradation of antibiotics driven by a microbial fuel cell includes:

[0065] A photoelectrocatalytic device includes a photoelectrocatalytic chamber and a photoanode and a carbon-based GDE cathode disposed within the photoelectrocatalytic chamber; the photoelectrocatalytic chamber is equipped with an aeration device for generating oxygen, which is located to the left of the GDE cathode and is used to fill the chamber with oxygen to generate hydrogen peroxide.

[0066] A microbial fuel cell system includes a bio-power generation chamber, which includes an anode chamber and a cathode chamber. The anode chamber is equipped with a carbon felt anode, and the cathode chamber is equipped with a platinum sheet cathode. The anode chamber and the cathode chamber are connected by a proton exchange membrane.

[0067] The photoanode is electrically connected to the platinum cathode via an external circuit; the carbon-based GDE cathode via an external circuit with a series resistor is electrically connected to the carbon felt anode.

[0068] Based on the above scheme, the photoanode adopts a visible light responsive composite photoanode material, which includes: a TiO2 nanotube array, a bismuth-based semiconductor confined within the TiO2 nanotubes, and bismuth nanoparticles attached to the surface of the bismuth-based semiconductor.

[0069] Based on the above scheme, the inner diameter of the TiO2 nanotube is 50~80nm and the tube length is 1~2μm;

[0070] The bismuth-based semiconductor has a particle size of 5-10 nm; the bismuth-based semiconductor has an in-tube coverage of >80%;

[0071] The bismuth nanoparticles have a particle size of 3-5 nm.

[0072] Based on the above scheme, the carbon-based GDE cathode is a nitrogen-doped porous carbon catalyst supported on it;

[0073] The carbon felt anode is a carbon felt enriched with electrogenic microorganisms, prepared by inoculating activated sludge from an urban wastewater treatment plant and acclimating it to antibiotics for 30 days.

[0074] This application also provides a method for the photoelectrocatalytic synergistic degradation of antibiotics driven by a microbial fuel cell, using the above-described system; including:

[0075] The photocatalytic reactants are placed in the photoelectrocatalytic chamber;

[0076] The reaction solution after photoelectrocatalytic degradation was placed in a bioelectricity generation chamber, and the photoanode was electrically connected to the external circuit of the platinum cathode; the series resistor of the external circuit of the carbon-based GDE cathode was electrically connected to the carbon felt anode.

[0077] Starting device;

[0078] Provide visible light to the photoelectrocatalytic chamber;

[0079] Photocatalysis and electrocatalysis synergistic degradation of antibiotics;

[0080] Microbial fuel cell drive and biodegradation provide bias voltage to the photoelectrocatalytic chamber.

[0081] Based on the above scheme, the photocatalytic-electrocatalytic synergistic degradation of antibiotics specifically involves,

[0082] Visible light excites the photoanode to generate electron-hole pairs; electrons are transferred to the carbon-based GDE cathode via an external circuit, while holes remain at the photoanode to oxidize water and generate ·OH; electrons at the cathode undergo a two-electron reduction reaction with dissolved oxygen, and the in-situ generated H2O2, along with holes and ·OH, synergistically oxidizes antibiotics.

[0083] Based on the above scheme, the cathode electrons undergo a two-electron reduction reaction with dissolved oxygen as follows: O₂ + 2H₂ + +2e - →H2O2.

[0084] Based on the above scheme, the microbial fuel cell drive and biodegradation provide a bias voltage for the photoelectrocatalytic chamber, specifically,

[0085] The intermediate product of photoelectrocatalysis is degraded on the carbon felt anode, and the generated electrons are transferred to the external circuit through the carbon felt anode to provide bias voltage for the photoelectrocatalytic chamber; protons migrate to the photoelectrocatalytic chamber through the exchange membrane to participate in the H2O2 generation reaction and achieve charge balance.

[0086] Based on the above scheme, the bio-electricity generation chamber and the photoelectrocatalytic chamber are connected by a pipeline. The intermediate products flowing out of the photoelectrocatalytic chamber enter the anode chamber of the bio-electricity generation chamber through the pipeline as substrates, and are then degraded by the carbon felt anode.

[0087] Based on the above scheme, the reaction conditions are as follows:

[0088] Visible light intensity set to 200~300mW / cm 2 Hydraulic retention time: 2-3 hours; Initial antibiotic concentration: 10-500 mg / L;

[0089] The series resistance of the external circuit is 10~50Ω;

[0090] The dissolved oxygen level in the photoelectrocatalytic chamber is maintained at 5-8 mg / L.

[0091] SOUR is an important indicator for evaluating the metabolic activity of activated sludge. This study examines the changes in SOUR of activated sludge in a photoelectrocatalytic coupled microbial fuel cell system and a traditional microbial fuel cell system.

[0092] To verify the effectiveness of this application, a suitable amount of sludge-water mixture was taken during the aeration stage of the bioreactor, centrifuged, and the supernatant was discarded. The sludge at the bottom of the centrifuge tube was transferred to a conical flask equipped with a magnetic stirrer, and pre-aerated experimental water (with the same composition as the influent to each reactor) was added. The flask was immediately sealed with sealing film. A dissolved oxygen meter probe was inserted, allowing a small amount of liquid to overflow to ensure there were no air bubbles inside the flask. The conical flask was placed on the magnetic stirrer, and after the dissolved oxygen meter reading stabilized, the DO value inside the flask was recorded every 30 seconds. After the experiment, the MLVSS of the sludge-water mixture in the conical flask was measured. The specific oxygen consumption rate (SOUR) was calculated as follows: SOUR = dc (dissolved oxygen consumption) / dt × MLVSS

[0093] like Figure 2As shown in the figure, on day 5 after acclimatization, the SOUR of activated sludge in the two bioreactor groups were 39.67±1.72 and 41.34±1.17 mg O2 / (g MLVSS·h), respectively, indicating that the metabolic activity of microorganisms in each bioreactor was basically the same. In the single microbial fuel cell system, the SOUR of activated sludge was strongly inhibited by day 10, decreasing to 28.94±1.81 mg O2 / (g MLVSS·h). Compared with the single biodegradation reactor, the degree of inhibition of SOUR in the bioreactor after degradation by the photoelectrocatalytic coupled microbial fuel cell system was significantly reduced, indicating that photoelectrocatalytic degradation significantly reduced the impact of antibiotics on the bioreactor. When the reactor operated for 20 days, the SOUR of activated sludge in the single biodegradation reactor decreased to 15.97±1.10 mg O2 / (g MLVSS·h). After photoelectrochemical degradation by photoelectrode, the SOUR of activated sludge decreased to 31.44±1.93 mg O2 / (g MLVSS·h). This indicates that the degradation process of the photoelectrochemical coupling system effectively reduced the concentration of antibiotics in the water, converting them into less toxic intermediate products. Therefore, the degradation by this system significantly reduced the inhibitory effect of antibiotics on the SOUR of activated sludge in subsequent biological treatment processes.

[0094] The production of reactive oxygen species (ROS) is an important indicator reflecting the level of cellular oxidative stress. As a byproduct of aerobic metabolism, ROS plays a crucial role in maintaining cellular function. Under normal circumstances, the intracellular antioxidant system can effectively reduce oxidative damage from ROS. However, under external environmental stimuli, the production of cellular ROS increases dramatically, causing oxidative damage to cells through direct or indirect interactions with DNA, proteins, and other components. Therefore, this experiment evaluated the biotoxic effects of different treatment processes on activated sludge in a bioreactor by measuring the ROS production in activated sludge.

[0095] like Figure 3 As shown, the ROS generation of activated sludge in the biodegradation reactor at day 5 of the experiment was used as the control group (100%), at which point the metabolic activity of microorganisms in the activated sludge of each bioreactor was basically the same. In the traditional single-microbial fuel cell system, ROS generation significantly increased to 176.4% by day 20, and gradually increased with the extension of operating time. This indicates that higher antibiotic concentrations in the water can promote ROS generation, and excessive ROS generation can disrupt the dynamic balance of intracellular oxidation-antioxidation processes, inducing severe oxidative damage to the activated sludge. Compared with the single biodegradation reactor, the ROS generation of activated sludge in the subsequent biological treatment process after degradation by the photoelectrocatalytic coupling system was significantly reduced, indicating that degradation by the photoelectrocatalytic coupling system significantly reduced the impact of antibiotics on the bioreactor.

[0096] In specific implementation,

[0097] The reactive oxygen species (ROS) content in activated sludge was determined using an ROS detection kit (Beyotime Biotechnology Research Institute, Jiangsu Province). The specific steps are as follows:

[0098] (1) Take 30 mL of activated sludge suspension, centrifuge at 6000 g for 5 min and discard the supernatant, then wash repeatedly 3 times with 0.1 M PBS (pH=7.4);

[0099] (2) Dissolve the sludge at the bottom of the centrifuge tube in PBS containing 50 μM DCFH-DA and incubate in the dark at room temperature for 0.5 h; after centrifugation, discard the supernatant and wash with PBS 3 times to remove DCFH-DA probes that have not entered the cells.

[0100] (3) Dissolve the sludge at the bottom of the centrifuge tube after the above operation into the corresponding experimental influent and continue to incubate in the dark for 1.5 h; after centrifugation, take the supernatant and use a fluorescence spectrophotometer (F-4600, Hitachi, Japan) to detect the fluorescence intensity of the generated DCF at a wavelength of 488 / 525 nm (Ex / Em).

[0101] like Figures 4-5 As shown, the degradation rate of norfloxacin using the system of this application and the conventional bismuth-modified photoelectrocatalytic system reached 95% (compared to 80% for the conventional bismuth-modified system), with a reaction rate constant of 0.035 min. -1 (1.8 times that of the traditional system) More thorough mineralization: TOC removal rate > 70% (traditional photoelectrocatalysis is only 40%, photocatalysis-MFC coupling system is 55%), degradation product toxicity is reduced by 90% (assessed by TEST software), and there is no risk of secondary pollution.

[0102] Figure 4 The degradation efficiency and total organic carbon (TOC) of levofloxacin (LEV) by Bi / BWO / TNAs in both conventional photoelectrocatalytic systems and photoelectrocatalytic-MFC coupled systems are presented. As shown in the figures, compared to the conventional photoelectrocatalytic system, the degradation rate of levofloxacin in the photoelectrocatalytic-MFC coupled system increased from 90.3% to over 95%. The total organic carbon removal efficiency also improved, increasing from 39.7% to 55.4%.

[0103] According to the TEST software evaluation results, see Figure 5 Most of the products are less toxic than levofloxacin products and pose no risk of secondary pollution.

[0104] Specifically, this invention presents a synergistic system of "confined encapsulated photoanode + MFC self-driven + in-situ H2O2 production"; constructing a green self-driven energy system: replacing the external bias voltage with a dual-chamber MFC, realizing electricity generation by microbial degradation of photoelectrocatalytic intermediates, outputting a stable voltage (0.6~0.8V) to meet the photoelectrocatalytic requirements; the entire process requires no fossil energy input, processing 1m³ of energy. 3 Wastewater carbon emissions are reduced to < 0.3 kg CO2 (75% lower than traditional technologies), achieving in-situ clean generation of H2O2: Based on a carbon-based GDE cathode, H2O2 production is achieved through a two-electron oxygen reduction reaction driven by an MFC, resulting in a stable H2O2 yield of 50~80 mg / h.

[0105] Specifically, the method for determining the yield of H2O2 is as follows:

[0106] The concentration of H2O2 is calculated by titrating the iodine produced from the reaction of H2O2 with potassium iodide. The chemical equation is: H2O2 + 2KI + H2SO4 → I2 + K2SO4 + 2H2O. Specifically, samples are taken every 10 minutes for titration. The iodine produced is titrated with a standard sodium thiosulfate solution, indirectly determining the H2O2 content. The chemical equation for this titration is: I2 + 2Na2S2O3 → 2NaI + Na2S4O6. By measuring the volume of sodium thiosulfate consumed during the titration and combining it with its concentration, the amount of I2 produced can be calculated, and thus the H2O2 content in the original sample can be deduced.

[0107] Obviously, those skilled in the art can make various modifications and variations to this application without departing from the spirit and scope of this application. Therefore, if such modifications and variations fall within the scope of the claims of this application and their equivalents, this application also intends to include such modifications and variations.

Claims

1. A system for the photoelectrocatalytic synergistic degradation of antibiotics driven by a microbial fuel cell, characterized in that, include: A photoelectrocatalytic device, comprising a photoelectrocatalytic chamber and a photoanode and a carbon-based GDE cathode disposed within the photoelectrocatalytic chamber; The photoelectrocatalytic chamber is equipped with an aeration device for generating oxygen. The aeration device is located on the left side of the GDE cathode and is used to fill the chamber with oxygen to generate hydrogen peroxide. A microbial fuel cell system includes a bio-power generation chamber, which includes an anode chamber and a cathode chamber. The anode chamber is equipped with a carbon felt anode, and the cathode chamber is equipped with a platinum sheet cathode. The anode chamber and the cathode chamber are connected by a proton exchange membrane. The photoanode is electrically connected to the platinum cathode via an external circuit; the carbon-based GDE cathode via an external circuit with a series resistor is electrically connected to the carbon felt anode. The photoanode is a visible light responsive composite photoanode material, which includes: a TiO2 nanotube array, a bismuth-based semiconductor confined within the TiO2 nanotubes, and bismuth nanoparticles attached to the surface of the bismuth-based semiconductor. The inner diameter of the TiO2 nanotube is 50~80nm, and the tube length is 1~2μm; The bismuth-based semiconductor has a particle size of 5-10 nm; the bismuth-based semiconductor has an in-tube coverage of >80%; The bismuth nanoparticles have a particle size of 3-5 nm.

2. The system for photoelectrocatalytic synergistic degradation of antibiotics driven by a microbial fuel cell as described in claim 1, characterized in that, The carbon-based GDE cathode is a nitrogen-doped porous carbon catalyst supported on it. The carbon felt anode is a carbon felt enriched with electrogenic microorganisms, prepared by inoculating activated sludge from an urban wastewater treatment plant with carbon felt and acclimating it to antibiotics for 30 days.

3. A method for the photoelectrocatalytic synergistic degradation of antibiotics driven by a microbial fuel cell, characterized in that, Using the system as described in any one of claims 1-2; comprising: The photocatalytic reactants are placed in the photoelectrocatalytic chamber; The reaction solution after photoelectrocatalytic degradation was placed in a bioelectricity generation chamber, and the photoanode was electrically connected to the external circuit of the platinum cathode; the series resistor of the external circuit of the carbon-based GDE cathode was electrically connected to the carbon felt anode. Starting device; Provide visible light to the photoelectrocatalytic chamber; Photocatalysis and electrocatalysis synergistic degradation of antibiotics; Microbial fuel cell drive and biodegradation provide bias voltage to the photoelectrocatalytic chamber.

4. The method for photoelectrocatalytic synergistic degradation of antibiotics driven by a microbial fuel cell as described in claim 3, characterized in that, The photocatalytic-electrocatalytic synergistic degradation of antibiotics specifically refers to... Visible light excites the photoanode to generate electron-hole pairs; electrons are transferred to the carbon-based GDE cathode via an external circuit, while holes remain at the photoanode to oxidize water and generate ·OH; electrons at the cathode undergo a two-electron reduction reaction with dissolved oxygen, and the in-situ generated H2O2, along with holes and ·OH, synergistically oxidizes antibiotics.

5. The method for photoelectrocatalytic synergistic degradation of antibiotics driven by a microbial fuel cell as described in claim 4, characterized in that, The cathode electrons undergo a two-electron reduction reaction with dissolved oxygen: O₂ + 2H₂ + +2e - →H2O2.

6. The method for photoelectrocatalytic synergistic degradation of antibiotics driven by a microbial fuel cell as described in claim 4, characterized in that, The microbial fuel cell drive and biodegradation provide a bias voltage for the photoelectrocatalytic chamber, specifically, The intermediate product of photoelectrocatalysis is degraded on the carbon felt anode, and the generated electrons are transferred to the external circuit through the carbon felt anode to provide bias voltage for the photoelectrocatalytic chamber; protons migrate to the photoelectrocatalytic chamber through the exchange membrane to participate in the H2O2 generation reaction and achieve charge balance.

7. The method for photoelectrocatalytic synergistic degradation of antibiotics driven by a microbial fuel cell as described in claim 3, characterized in that, The bio-electricity generation chamber and the photoelectrocatalytic chamber are connected by a pipeline. The intermediate products flowing out of the photoelectrocatalytic chamber enter the anode chamber of the bio-electricity generation chamber through the pipeline as substrates, and are then degraded by the carbon felt anode.

8. The method for photoelectrocatalytic synergistic degradation of antibiotics driven by a microbial fuel cell as described in claim 3, characterized in that, The reaction conditions are: Visible light intensity set to 200~300mW / cm 2 Hydraulic retention time: 2-3 hours; Initial antibiotic concentration: 10-500 mg / L; The series resistance of the external circuit is 10~50Ω; The dissolved oxygen level in the photoelectrocatalytic chamber is maintained at 5-8 mg / L.

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