A pollution early warning method and system based on a microbial fuel cell

Abstract

The application discloses a pollution early warning method and system based on a microbial fuel cell, and the method is as follows: collecting background output signals of a microbial fuel cell transducer of a monitoring point of an underground pipe gallery when the transducer contacts a first type of liquid and response output signals when the transducer contacts a second type of liquid, setting an early warning threshold and a reset threshold according to the background output signals and the response output signals; acquiring real-time output electric signals of the transducer when the transducer contacts a to-be-detected liquid and a current end voltage value of an energy storage unit; when the current end voltage value reaches a wake-up voltage threshold, processing the real-time output electric signals to obtain target output signals; comparing the target output signals with the early warning threshold and the reset threshold, and when the target output signals reach or exceed the early warning threshold, counting a duration; if the duration reaches an anti-shake duration and the target output signals still reach or exceed the early warning threshold when the duration ends, generating a pollution early warning, and therefore, the pollution early warning can be accurately performed in a severe, humid and signal-fluctuation underground pipe gallery.

Description

Technical Field

[0001] This application relates to the field of pollution early warning, and in particular to a pollution early warning method and system based on microbial fuel cells. Background Technology

[0002] The underground utility tunnels of the main urban power grid are responsible for the centralized laying and operation of power cables, joints, and ancillary facilities. These tunnels are enclosed environments with high humidity, dispersed locations, and limited construction and modification capabilities, placing extremely high demands on long-term operation. In this harsh, humid environment with significant signal fluctuations, incidents such as groundwater leakage, localized water accumulation, external sewage backflow, and intrusion of abnormally contaminated liquids occur frequently. These abnormal liquids not only exacerbate facility corrosion and reduce insulation safety margins but may also directly induce equipment failures or power outages. Therefore, timely, continuous, and low-maintenance early warning systems for liquid conditions within the tunnels are essential. However, due to poor lighting, severe obstruction of visibility, short inspection windows, and the difficulty in obtaining continuous external power to distributed nodes, traditional centralized or high-power monitoring methods are difficult to deploy effectively. There is an urgent need for an early warning solution that can adapt to on-site constraints such as low illumination, high humidity, and unstable signals, and can autonomously identify pollution events.

[0003] Current underground utility tunnel liquid monitoring primarily relies on methods such as liquid level detection, conductive probes, video surveillance, and manual inspection. Liquid level and conductive probe detection can typically only determine whether there is water or not and the approximate water depth, but cannot distinguish between ordinary seepage and sewage containing high organic pollution loads, backflow fluid, or external contaminated liquids. Their output information is limited and easily confused with clean water accumulation and contaminated intrusion. Cameras are affected by water mist, condensation, and obstruction, resulting in large fluctuations in image quality and a significant decrease in recognition accuracy. Manual inspections are time-consuming and have a strong lag, making it difficult to capture sudden pollution events. Furthermore, while conventional water quality monitoring equipment (such as online COD / BOD analyzers) can quantitatively detect organic matter content, they rely on external power supplies, chemical reagents, and regular calibration and maintenance, resulting in high power consumption and large size, making them unsuitable for the low-power, distributed, and maintenance-free deployment requirements within utility tunnels. Summary of the Invention

[0004] This application provides a pollution early warning method and system based on microbial fuel cells, which can accurately provide pollution early warning in harsh, humid underground utility tunnels with large signal fluctuations.

[0005] This application provides a pollution early warning method based on microbial fuel cells, including: The background output signal of the microbial fuel cell transducer installed at the monitoring point of the underground utility tunnel of the power grid is collected when it comes into contact with the first type of liquid and the response output signal when it comes into contact with the second type of liquid. Based on the background output signal and the response output signal, a warning threshold and a reset threshold are set. The real-time output electrical signal generated by the microbial fuel cell transducer at the monitoring point of the underground pipe gallery when it comes into contact with the liquid to be tested is obtained, and the current terminal voltage value of the energy storage unit that provides power to the back-end signal processing circuit of the transducer is obtained. The current terminal voltage value is compared with a preset wake-up voltage threshold. If the current terminal voltage value reaches or exceeds the wake-up voltage threshold, the real-time output electrical signal is processed to obtain the target output signal. The target output signal is compared with the warning threshold and the reset threshold respectively. When the target output signal reaches or exceeds the warning threshold, the duration of exceeding the warning threshold is counted. When the duration reaches the preset anti-jitter duration and the target output signal still reaches or exceeds the warning threshold at the end of the anti-jitter duration, a pollution warning for the underground utility tunnel of the power grid is generated.

[0006] This application achieves in-situ calibration for different underground utility tunnel monitoring points by collecting the output signals of the transducer when it comes into contact with the first type of liquid (background liquid) and the second type of liquid (response liquid) and setting warning thresholds and reset thresholds accordingly. This effectively eliminates baseline drift caused by electrode aging, fluctuations in biofilm activity, and changes in temperature and humidity, laying the foundation for establishing a reliable discrimination benchmark in harsh, humid, and highly fluctuating utility tunnel environments. Furthermore, by introducing a comparison mechanism between the energy storage unit's terminal voltage and the wake-up voltage threshold, it ensures that the back-end signal processing circuit only activates signal processing when energy storage is sufficient. This avoids erroneous judgment results due to comparator or amplifier malfunction caused by insufficient power supply, thus ensuring the reliability of the early warning action. Furthermore, by comparing the target output signal with both the early warning threshold and the reset threshold, and introducing a jitter reduction period to statistically analyze and determine the duration exceeding the early warning threshold, an early warning is triggered only when the signal consistently meets the standard and remains in a compliant state at the end of the jitter reduction. This effectively filters out instantaneous spikes or noise glitches caused by liquid impact, electrode polarization, poor contact, and electromagnetic interference, avoiding frequent false triggering and repeated jumps in alarm status near the threshold. These measures work together in a progressive manner to ensure that, even in special scenarios such as underground utility tunnels with limited power supply and strong interference, this application can still accurately identify abnormal liquid intrusion events with high organic pollution loads, significantly reducing the risk of missed and false alarms.

[0007] Further, the step of setting the warning threshold and reset threshold based on the background output signal and the response output signal includes: Calculate the difference between the response output signal and the background output signal; Calculate the product of the difference and the preset threshold adjustment coefficient, and determine the warning threshold based on the background output signal and the product; A reset threshold for determining the falling edge of the signal is set according to the warning threshold, wherein the reset threshold is lower than the warning threshold and higher than the background output signal.

[0008] By setting a reset threshold that is lower than the warning threshold but higher than the background signal threshold, a hysteresis comparison interval is formed. This effectively avoids frequent alarm interruptions and false triggers caused by the output signal repeatedly crossing the threshold in environments with dampness and signal fluctuations in underground utility tunnels, thus significantly improving the stability and accuracy of the warning.

[0009] Furthermore, this application also includes: If the current terminal voltage value is lower than the wake-up voltage threshold, the energy storage unit is determined to be in a low-energy state, and the back-end signal processing circuit is controlled to maintain a power-off sleep state.

[0010] This keeps the signal processing circuit powered off and in hibernation when energy storage is insufficient, avoiding false signals caused by abnormal circuit operation under low voltage. It ensures that detection and judgment are only performed when energy is sufficient, effectively preventing false alarms caused by unstable power supply in harsh environments and improving system reliability.

[0011] Further, the processing of the real-time output electrical signal to obtain the target output signal includes: The real-time output electrical signal is subjected to low-pass filtering to remove high-frequency noise and transient disturbances, resulting in a processed signal; The processed signal is amplified using low-power amplification to a level range recognizable by the comparator, thereby obtaining the target output signal.

[0012] This approach first removes high-frequency noise and transient disturbances from the underground utility tunnel by low-pass filtering the real-time output electrical signal, and then amplifies it at a low power level to a level recognizable by the comparator. This effectively suppresses interference components in humid or fluctuating environments, ensuring the authenticity of the target output signal and the accuracy of subsequent threshold comparisons.

[0013] Furthermore, after the duration of the statistical data exceeding the warning threshold is reached, the method further includes: If, within the preset anti-shake duration, the target output signal falls below the reset threshold and continues for more than the preset reset time, the currently recorded duration is cleared and the timing is reset. The timing restarts when the target output signal reaches or exceeds the warning threshold again.

[0014] If the signal drops below the reset threshold within the anti-jitter duration and continues to exceed the reset time, the timer is reset and cleared. This prevents the accumulation of abnormal timing status caused by instantaneous fluctuations in the underground utility tunnel signal, ensuring that the warning is triggered only under a continuous and stable pollution response, thereby improving anti-interference capability and judgment accuracy.

[0015] Furthermore, after comparing the target output signal with the warning threshold and the reset threshold respectively, the method further includes: When the target output signal is below the reset threshold, it is determined that the liquid under test has not met the warning conditions, and the state of no warning is maintained.

[0016] This maintains a no-warning state when the target output signal is below the reset threshold, preventing normal background fluctuations in underground utility tunnels from being misjudged as pollution events. It ensures that the system only lifts the alarm state when the signal clearly falls back to the safe range, thus achieving accurate differentiation between normal seepage and contaminated liquid.

[0017] Furthermore, this application also includes: Calculate the response increment of the real-time output electrical signal relative to the background output signal; Divide the response increment by the background output signal to obtain the normalized response quantity; The normalized response quantity is compared with a preset normalized warning threshold. When the normalized response quantity reaches or exceeds the normalized warning threshold and the duration reaches the anti-shake duration, the pollution warning is generated.

[0018] This normalized response eliminates baseline deviations caused by biofilm conditions, electrode aging, and temperature changes in different transducers, ensuring consistency of early warning criteria across different monitoring locations and environments, and effectively overcoming the impact of complex underground utility tunnel conditions on signal accuracy.

[0019] Furthermore, following the pollution warning for the generated underground utility tunnel, the following is also included: A high-level digital warning signal is generated based on the pollution warning. The high-level digital warning signal triggers the local audible and visual alarm module to output an audible and visual alarm, and / or wakes up the low-power wireless communication module to remotely upload the warning information to the monitoring backend.

[0020] This system generates a high-level digital signal upon confirmation of pollution, directly triggering audible and visual alarms and remote reporting via wireless communication modules. This enables linkage between local warnings and remote notifications, overcoming the limitations of the enclosed environment of underground utility tunnels on signal transmission and ensuring reliable transmission and timely handling of early warning information.

[0021] Another embodiment of this application also provides a pollution early warning system based on microbial fuel cells, including: A microbial fuel cell transducer is installed at a monitoring point in an underground utility tunnel of a power grid. The microbial fuel cell transducer includes a reactor shell, an anode disposed inside the shell, an air cathode disposed on the shell, and a microbial membrane attached to the surface of the anode. An energy storage unit, wherein the power input terminal of the energy storage unit is connected to the power output terminal of the microbial fuel cell transducer, is used to collect and store the power generated by the sensing unit during the power generation process; A wake-up control unit, the input terminal of which is connected to the voltage detection terminal of the energy storage unit; The signal conditioning unit has its signal input terminal connected to the signal output terminal of the microbial fuel cell transducer, and its control terminal connected to the output terminal of the wake-up control unit.

[0022] Furthermore, the reactor shell is made of an insulating and corrosion-resistant material. The anode is a graphite rod, carbon felt, carbon brush, or carbon cloth disposed within the shell. The air cathode is disposed on the open side or sidewall of the shell, and the air cathode includes a conductive substrate and a catalytic conductive layer disposed on the surface of the conductive substrate. A porous ceramic sleeve is disposed around the anode between the anode and the cathode to prevent physical short circuits between the anode and the cathode and to provide an attachment support interface for the microbial membrane. The microbial membrane is an anode biofilm formed by the domestication of a mixed microbial community derived from activated sludge from a wastewater treatment system or sediment from a drainage ditch. The biofilm contains electroactive microorganisms with extracellular electron transfer capabilities. Attached Figure Description

[0023] To more clearly illustrate the technical solution of this application, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0024] Figure 1 This is a schematic diagram of the structure of the microbial fuel cell sensing unit provided in this application; Figure 2 This is a schematic flowchart of an embodiment of the pollution early warning method based on microbial fuel cells provided in this application; Figure 3 This is a schematic diagram of the microbial fuel cell array and its installation structure as described in this application; Figure 4 This is a block diagram of the signal processing and threshold judgment circuit of this application. Detailed Implementation

[0025] To make the objectives, technical solutions, and advantages of this application clearer, the technical solutions of this application will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of this application, not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0026] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application pertains; the terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the application; the terms “comprising” and “having”, and any variations thereof, in the specification, claims, and foregoing description of the drawings are intended to cover non-exclusive inclusion.

[0027] In the description of the embodiments of this application, technical terms such as "first" and "second" are used only to distinguish different objects and should not be construed as indicating or implying relative importance or implicitly specifying the number, specific order, or primary and secondary relationship of the indicated technical features. In the description of the embodiments of this application, "multiple" means two or more, unless otherwise explicitly defined.

[0028] In this document, the term "embodiment" means that a particular feature, structure, or characteristic described in connection with an embodiment may be included in at least one embodiment of this application. The appearance of this phrase in various places throughout the specification does not necessarily refer to the same embodiment, nor is it a separate or alternative embodiment mutually exclusive with other embodiments. It will be explicitly and implicitly understood by those skilled in the art that the embodiments described herein can be combined with other embodiments.

[0029] In the description of the embodiments in this application, the term "and / or" is merely a description of the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A existing alone, A and B existing simultaneously, and B existing alone. Additionally, the character " / " in this document generally indicates that the preceding and following related objects have an "or" relationship.

[0030] In the description of the embodiments of this application, the term "multiple" refers to two or more (including two), similarly, "multiple sets" refers to two or more (including two sets), and "multiple pieces" refers to two or more (including two pieces).

[0031] In the description of the embodiments of this application, unless otherwise expressly specified and limited, technical terms such as "installation," "connection," "joining," and "fixing" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. For those skilled in the art, the specific meaning of the above terms in the embodiments of this application can be understood according to the specific circumstances.

[0032] like Figure 1 As shown, Figure 1 This is a schematic diagram of the microbial fuel cell sensing unit provided in this application. The diagram shows the reactor shell, graphite anode rod, carbon cathode, porous support partition structure or ceramic bacterial chamber located between the anode and cathode, and the basic configuration of the reaction between organic wastewater (or abnormal liquid) and oxygen on the cathode side within the reaction area. It illustrates the composition and power generation mechanism of the microbial fuel cell sensing unit. In this embodiment, the microbial fuel cell transducer preferably adopts a single-chamber proton exchange membrane-free structure. The reactor shell is made of insulating and corrosion-resistant material, preferably polyethylene terephthalate, but polypropylene, polyethylene, glass, ceramic, or acrylic materials can also be used. The shell serves as both the reaction space and facilitates observation of the internal state and adapts to the installation conditions of underground pipe racks. The anode is located inside the shell and is preferably a conductive material suitable for microbial attachment, such as a graphite rod, carbon felt, carbon brush, or carbon cloth. The air cathode is located on the open side or sidewall of the shell, with a substrate of stainless steel mesh, carbon cloth, or carbon paper, and a conductive layer of activated carbon or an equivalent catalytic conductive layer on its surface. A porous support partition, preferably a porous ceramic sleeve, is installed around the anode. This sleeve is positioned between the anode and cathode to prevent physical short circuits and to provide an interface for the attachment and growth of the mixed microbial community. A microbial biofilm adheres to the anode surface. This biofilm is formed by the domestication of a mixed microbial community derived from activated sludge from wastewater treatment systems or sediment from drainage ditches, and contains electroactive microorganisms with extracellular electron transfer capabilities. Compared to single pure strains, the mixed microbial community exhibits better environmental adaptability and operational stability when facing the complex liquid composition, fluctuating pollution loads, and changes in temperature and humidity in underground pipe corridors.

[0033] Its working mechanism is as follows: When liquid from the underground utility tunnel enters the reaction zone of the microbial fuel cell, if the liquid contains biodegradable organic matter, the microorganisms in the anode biofilm will use this biodegradable organic matter as an electron donor for metabolic oxidation, releasing electrons and protons during the metabolic process. Electrons are collected at the anode and transferred to the cathode through an external circuit, while protons migrate to the cathode region through the electrolyte environment and undergo a reduction reaction with electrons and oxygen on the cathode side, thereby forming a measurable voltage or current output between the anode and cathode. Within a certain operating range, the voltage, current, or power output of the microbial fuel cell, or the power converted by the load, shows a positive correlation with the content of biodegradable organic matter in the liquid entering the reaction zone. This transducer is the "microbial fuel cell transducer installed at the monitoring point of the underground utility tunnel" mentioned in this application.

[0034] It should be noted that the transducer and the early warning nodes it constitutes are particularly suitable for distributed deployment in locations such as low-lying water accumulation points, drainage ditches, sump pits, leakage risk points, and inspection well connection areas in underground power grid tunnels, enabling long-term, low-maintenance monitoring of the liquid status in the aforementioned areas.

[0035] See Figure 2 To accurately predict pollution in harsh, humid underground utility tunnels with fluctuating signals, this application provides a pollution prediction method based on microbial fuel cells, comprising steps S201 to S204: S201, Collect the background output signal of the microbial fuel cell transducer installed at the monitoring point of the underground utility tunnel of the power grid when it comes into contact with the first type of liquid and the response output signal when it comes into contact with the second type of liquid, and set the warning threshold and the reset threshold according to the background output signal and the response output signal. In some embodiments, the background output signal of the microbial fuel cell transducer installed at the monitoring point of the underground utility tunnel is collected when it comes into contact with a first type of liquid, and the response output signal is collected when it comes into contact with a second type of liquid. Specifically, before commissioning, during on-site commissioning, or during maintenance and reset, the system collects the microbial fuel cell output signal under the conditions of clean water, common seepage in underground utility tunnels, condensate, rainwater infiltration, or low organic load water accumulation (first type of liquid, i.e., liquid with low organic content) to form a background reference voltage. or background reference current Simultaneously, the output signals of the microbial fuel cell were collected under typical domestic sewage, backflow liquid containing organic pollutants, abnormal drainage liquid, or a preset organic pollution load sample liquid (Class II liquid, i.e., liquid with a high content of biodegradable organic matter), to generate an abnormal response voltage. or abnormal response current .

[0036] It should be noted that the above collection process utilizes the output characteristics of microbial fuel cells: when the liquid entering the reaction zone is groundwater, condensate, rainwater infiltration, or other clean water with low organic matter content, the available organic substrate for the anode biofilm is limited, the microbial metabolic intensity is low, the external circuit electron transfer rate is low, and the output voltage or output current of the microbial fuel cell remains at a low background level; when domestic sewage, backflow water containing organic pollutants, abnormal drainage liquid, or other abnormal liquids with high biodegradable organic matter content enter the underground pipe gallery, the available organic substrate for the anode biofilm increases, the microbial metabolic intensity is enhanced, the extracellular electron transfer process is enhanced, the external circuit electron flow increases, and the output voltage or output current of the microbial fuel cell increases accordingly. Therefore, the output signal of the microbial fuel cell can reflect the changes in the organic pollution load in the liquid and can be used as a basis for distinguishing between clean water with low organic load and abnormal liquid with high organic pollution load.

[0037] It should be noted that this application does not require laboratory-level precise quantification of chemical oxygen demand (COD) or biochemical oxygen demand (BOD) in liquids using microbial fuel cells. Instead, it uses the output signal of the microbial fuel cell as a bioelectrochemical response quantity characterizing changes in organic pollution load, and employs a threshold-based digital early warning method for engineering judgment. In other words, the focus of this application is not on outputting continuous, precise concentration values, but on determining whether the liquid in the underground utility tunnel has reached a preset organic pollution load early warning level, thereby meeting the application requirements of low power consumption, low maintenance, and timely early warning in underground utility tunnel projects.

[0038] In some embodiments, setting a warning threshold and a reset threshold based on the background output signal and the response output signal includes: calculating the difference between the response output signal and the background output signal; calculating the product of the difference and a preset threshold adjustment coefficient; determining the warning threshold based on the background output signal and the product; and setting a reset threshold for signal falling edge determination based on the warning threshold, wherein the reset threshold is lower than the warning threshold and higher than the background output signal. Specifically, when a voltage signal is used as the determination quantity, the warning threshold... Set the background reference voltage With abnormal response voltage The specific settings are as follows: ,in This is the threshold adjustment coefficient. When the current signal is used as the judgment quantity, the warning threshold... Set background reference current With abnormal response current The intervals are set as follows: = + K×( - ), where K is the threshold adjustment coefficient. Reset threshold The setting method is: reset threshold Below the warning threshold And higher than the background reference signal ,Right now < < .

[0039] It should be noted that the threshold adjustment coefficient K ranges from 0 to 1, preferably from 0.3 to 0.8. The specific value of K is adjusted according to the on-site false alarm tolerance, early warning sensitivity requirements, and liquid type of the underground utility tunnel. A smaller K value is selected when it is necessary to improve early warning sensitivity, and a larger K value is selected when it is necessary to reduce the probability of false alarms.

[0040] In some embodiments, to avoid false triggering caused by liquid impact, electrode polarization, temperature changes, poor contact, or transient noise, this application preferably includes a hysteresis comparison structure in the comparison unit, or a duration criterion and a multiple sampling criterion in the digital decision logic. For example, only when the amplified output signal is sampled for a certain number of consecutive times above a warning threshold, or when the duration above the warning threshold exceeds the anti-jitter duration, will trigger a false triggering mechanism. The system only outputs a digital warning signal "1" when the output signal is below the reset threshold. And continues for more than the preset reset time Afterwards, the system returns to the digital signal "0". The purpose of setting the hysteresis interval and reset condition is to avoid repeated changes in the alarm state when the signal fluctuates near the threshold.

[0041] By setting a reset threshold that is lower than the warning threshold but higher than the background signal threshold, a hysteresis comparison interval is formed. This effectively avoids frequent alarm interruptions and false triggers caused by the output signal repeatedly crossing the threshold in environments with dampness and signal fluctuations in underground utility tunnels, thus significantly improving the stability and accuracy of the warning.

[0042] S202, acquire the real-time output electrical signal generated by the microbial fuel cell transducer at the monitoring point of the underground pipe gallery when it comes into contact with the liquid to be tested, and acquire the current terminal voltage value of the energy storage unit that provides power to the back-end signal processing circuit of the transducer. In some embodiments, when the liquid to be tested appears at the monitoring point of the underground utility tunnel and enters the reaction zone of the microbial fuel cell, the electroactive microorganisms in the anode biofilm metabolize and oxidize the biodegradable organic components in the liquid as electron donors. During metabolism, electrons and protons are released. Electrons are collected at the anode and transferred to the cathode through an external circuit, while protons migrate through the electrolyte environment to the cathode region and undergo a reduction reaction with electrons and oxygen. This generates a measurable voltage or current output signal between the anode and cathode, which is the response output of the microbial fuel cell transducer when it comes into contact with the liquid to be tested. On the other hand, to meet the needs of autonomous operation, the system is equipped with an energy storage module. Multiple microbial fuel cell units are arranged in series, parallel, or series-parallel configurations to form an array. The output of the array first charges the energy storage unit, and the electrical energy of the energy storage unit is used to supply the signal processing circuit at the back end. The system acquires the current terminal voltage value of the energy storage unit in real time, which reflects the amount of electrical energy currently stored in the energy storage unit.

[0043] Figure 3 This is a schematic diagram of the microbial fuel cell array and its installation structure according to this application. Figure 3 As shown, multiple microbial fuel cell transducers are arranged in an array within the installation frame, including individual reactors, upper fixed components, and lateral support components. Multiple units are connected in series, parallel, or series-parallel configurations to form an array, thereby enhancing overall energy output and meeting the power supply requirements of the digital early warning system in underground utility tunnel scenarios.

[0044] In one embodiment, a single microbial fuel cell can output a stable load voltage of about 0.14 volts, and an array of multiple units can achieve microwatt-level continuous power output, which is used to maintain low power comparison, state holding, periodic sampling, or charge energy storage units.

[0045] It should be noted that the phrase "the output of the microbial fuel cell array first charges the energy storage unit" is followed by "to achieve low-voltage charging, a boost DC-DC converter or charge pump is set between the microbial fuel cell array and the energy storage unit to boost the low voltage output of the array to the charging voltage of the energy storage unit, and a reverse-charging diode is used to prevent the energy storage unit from discharging in reverse."

[0046] By simultaneously acquiring the two physical quantities mentioned above, the system can sense changes in the organic pollution load in the liquid and also grasp its own energy storage status, thus providing a basis for deciding whether to start the signal processing process based on whether the energy is sufficient.

[0047] S203, compare the current terminal voltage value with a preset wake-up voltage threshold. If the current terminal voltage value reaches or exceeds the wake-up voltage threshold, process the real-time output electrical signal to obtain the target output signal. In some embodiments, the current terminal voltage value is compared with a preset wake-up voltage threshold. If the current terminal voltage value reaches or exceeds the wake-up voltage threshold, specifically, after the system obtains the current terminal voltage value of the energy storage unit, it compares the current terminal voltage value with the preset wake-up voltage threshold to determine whether the electrical energy currently stored in the energy storage unit is sufficient to support the back-end signal processing circuit to complete a complete detection and judgment operation. To adapt to the requirements of long-term low-maintenance operation of underground utility tunnels, the nodes are in a low-power standby or energy accumulation state most of the time and do not continuously monitor the output signal of the microbial fuel cell. Only when the energy storage voltage reaches the set start-up threshold will detection, alarm, or reporting actions be performed.

[0048] In some embodiments, processing the real-time output electrical signal to obtain the target output signal includes: sequentially performing low-pass filtering on the real-time output electrical signal to remove high-frequency noise and transient disturbances to obtain a processed signal; and performing low-power amplification on the processed signal to amplify it to a level range recognizable by the comparator to obtain the target output signal. Specifically, when the current terminal voltage value of the energy storage unit reaches or exceeds the wake-up voltage threshold, the system determines that the energy storage is sufficient, starts the back-end signal processing circuit, and inputs the continuous analog signal generated by the microbial fuel cell transducer into the signal conditioning module. This continuous analog signal is first filtered by the input filtering unit to remove high-frequency noise and transient disturbances, and filters out noise components coupled into the signal channel due to equipment start-up and shutdown, electromagnetic interference, or poor contact in the underground pipe gallery environment to obtain the processed signal. The filtered processed signal is then amplified by the low-power amplification unit to amplify the weak signal at the millivolt level to a level range recognizable by the comparator to obtain the target output signal. The amplitude of this target output signal is sufficient to meet the signal amplitude requirements of the comparator input, thus providing the prerequisite for subsequent accurate comparison of the target output signal with the warning threshold.

[0049] It should be noted that the continuous analog signal is specifically the open-circuit voltage, load voltage, and output current output by the microbial fuel cell, or the voltage signal obtained by sampling resistor conversion. Its amplitude is usually in the millivolt range, which is difficult to directly provide for subsequent circuits to identify and process.

[0050] This approach first removes high-frequency noise and transient disturbances from the underground utility tunnel by low-pass filtering the real-time output electrical signal, and then amplifies it at a low power level to a level recognizable by the comparator. This effectively suppresses interference components in humid or fluctuating environments, ensuring the authenticity of the target output signal and the accuracy of subsequent threshold comparisons.

[0051] In some embodiments, this application further includes: if the current terminal voltage value is lower than the wake-up voltage threshold, determining that the energy storage unit is in a low-energy state, and controlling the back-end signal processing circuit to maintain a power-off sleep state. Specifically, when the current terminal voltage value of the energy storage unit is lower than the wake-up voltage threshold, determining that the energy storage unit is in a low-energy state, controlling the back-end signal processing circuit to maintain a power-off sleep state, and continuing to charge the energy storage unit to accumulate energy from the microbial fuel cell array.

[0052] It should be noted that the power-off sleep state refers to cutting off the power supply to the back-end signal processing circuit through the load switch, so that the circuit is in a zero-power state; the wake-up control unit is directly powered by the energy storage unit and always maintains the terminal voltage monitoring capability.

[0053] This keeps the signal processing circuit powered off and in hibernation when energy storage is insufficient, avoiding false signals caused by abnormal circuit operation under low voltage. It ensures that detection and judgment are only performed when energy is sufficient, effectively preventing false alarms caused by unstable power supply in harsh environments and improving system reliability.

[0054] S204, compare the target output signal with the warning threshold and the reset threshold respectively. When the target output signal reaches or exceeds the warning threshold, count the duration of exceeding the warning threshold. When the duration reaches a preset anti-jitter duration and the target output signal still reaches or exceeds the warning threshold at the end of the anti-jitter duration, generate a pollution warning for the underground utility tunnel.

[0055] In some embodiments, the target output signal, after being filtered and amplified, is fed into one input of a comparator, while the other input of the comparator is connected to a reference voltage corresponding to the warning threshold. The reference voltage According to voltage warning threshold Current warning threshold Response increment threshold or normalized response threshold setting. The comparator compares the target output signal with a reference voltage. The comparison was made when the amplified signal was lower than the reference voltage. When the comparator outputs a low-level digital signal, recorded as "0", it indicates that no high organic pollution load has been detected, or the current liquid level has not reached the warning condition; when the amplified signal reaches or exceeds the reference voltage... When the comparator outputs a high-level digital signal, denoted as "1", it indicates that an abnormal liquid with a high organic pollution load has been detected. To avoid false triggering caused by liquid impact, electrode polarization, temperature changes, poor contact, or transient noise, the system does not directly use the comparator's instantaneous output as the warning result. Instead, duration criteria and multiple sampling criteria are set in the digital judgment logic. Specifically, the system starts counting the duration of this high-level state when the comparator outputs a high-level digital signal "1", that is, the duration during which the target output signal reaches or exceeds the warning threshold. This counted duration is compared with the preset anti-jitter duration. A comparison is made. Only when the target output signal exceeds the warning threshold for a duration longer than the preset anti-shake duration will the anti-shake mechanism be activated. Furthermore, at the end of the anti-shake duration, the target output signal still reaches or exceeds the warning threshold, i.e., the high-level digital signal "1" remains in... Only when the system remains stable for a period of time without any sudden changes will it confirm the detection of abnormal liquid with a high organic pollution load and generate a pollution warning for the underground utility tunnel.

[0056] It should be noted that, Figure 4 This is a block diagram of the signal processing and threshold judgment circuit of this application. Figure 4 As shown, the equivalent output of the microbial fuel cell transducer is connected to the pre-amplifier circuit. The amplified signal is input to the comparison module and compared with a reference threshold. When the amplified signal reaches or exceeds the warning threshold and the duration meets the preset anti-jitter duration condition, the comparator outputs a high-level digital warning signal to drive the subsequent alarm, control, or communication unit.

[0057] In some embodiments, after the duration exceeding the warning threshold is statistically calculated, the method further includes: if, within the preset anti-shake duration, the target output signal falls below the reset threshold and persists for more than a preset reset time, then the currently calculated duration is reset and the timing is restarted, waiting for the target output signal to reach or exceed the warning threshold again. Specifically, after the system starts timing, that is, within the preset anti-shake duration... The system continuously monitors changes in the target's output signal. This process is not simply a matter of waiting. Instead of making a judgment all at once after the duration ends, it is done in... Real-time tracking of the amplitude trend of the target output signal and its relationship to the warning threshold over a given period of time. and reset threshold The positional relationship. If, during the timing process, the target output signal exceeds the warning threshold... The state of the device deteriorated and further decreased to below the reset threshold. This indicates that the signal has moved out of the fluctuation range above the warning threshold and into the region below the reset threshold. At this point, the system does not immediately reset the timer, but instead initiates a reset. The count is continuously monitored to see if the target output signal is stably maintained below the reset threshold. The state. Only when the target output signal is below the reset threshold. The duration exceeds the preset reset time Only after confirming that the current liquid event has subsided or the signal disturbance has sufficiently subsided, does the system reset the accumulated duration exceeding the warning threshold to zero and restore the timing state to its initial zero. After resetting and clearing, the system no longer continues the previously accumulated timing data but enters a waiting state, awaiting the return of the target output signal when it again reaches or exceeds the warning threshold. When the timer restarts from zero, there is a hysteresis interval between the reset threshold and the warning threshold, which satisfies... < < The relationship.

[0058] If the signal drops below the reset threshold within the anti-jitter duration and continues to exceed the reset time, the timer is reset and cleared. This prevents the accumulation of abnormal timing status caused by instantaneous fluctuations in the underground utility tunnel signal, ensuring that the warning is triggered only under a continuous and stable pollution response, thereby improving anti-interference capability and judgment accuracy.

[0059] In some embodiments, after comparing the target output signal with the warning threshold and the reset threshold respectively, the method further includes: when the target output signal is below the reset threshold, determining that the liquid to be tested has not met the warning condition, and maintaining a no-warning state. Specifically, when the target output signal is below the reset threshold... When the signal reaches this state, it means that the signal has not reached the warning threshold. It has even fallen below the reset threshold. The current level indicates that the content of biodegradable organic matter in the liquid entering the reaction zone is low, the amount of available organic substrate for the anode biofilm is limited, the microbial metabolic intensity is low, the electron transfer rate of the external circuit is low, and the output voltage or current of the microbial fuel cell remains at a low level. At this time, the system determines that the liquid under test has not met the warning conditions, i.e., the current liquid is clear water, ordinary seepage, low organic load liquid, or does not contain enough organic pollution load to trigger a warning. The comparator maintains a low-level digital signal output of "0", the local audible and visual alarm module does not activate, the microcontroller does not trigger an interrupt, the wireless communication module remains in sleep or standby mode, and the entire warning system remains in a no-warning state. Only when the target output signal rises and reaches or exceeds the warning threshold again will the warning system be activated. Only when the preset anti-shake duration condition is met will the system re-enter the warning judgment process and output a high-level digital signal "1".

[0060] This maintains a no-warning state when the target output signal is below the reset threshold, preventing normal background fluctuations in underground utility tunnels from being misjudged as pollution events. It ensures that the system only lifts the alarm state when the signal clearly falls back to the safe range, thus achieving accurate differentiation between normal seepage and contaminated liquid.

[0061] In some embodiments, this application further includes: calculating the response increment of the real-time output electrical signal relative to the background output signal; dividing the response increment by the background output signal to obtain a normalized response quantity; comparing the normalized response quantity with a preset normalized warning threshold, and generating the pollution warning when the normalized response quantity reaches or exceeds the normalized warning threshold and the duration reaches the anti-jitter duration. Specifically, to further improve the reliability of the judgment, the system uses a relative response quantity for judgment, obtaining the response increment by comparing the real-time output signal of the microbial fuel cell with a background reference signal. If a voltage signal is used, the response increment... Represented as: = - Normalized response This is represented as: = / This involves dividing the response increment by the background reference voltage to obtain a dimensionless normalized value. If a current signal is used, the response increment... Represented as: ,in This indicates the real-time output current of the microbial fuel cell. This represents the background reference current. The normalized response RI is expressed as: = / When ordinary seepage, condensate, or low-organic-load water enters the underground utility tunnel, the real-time output signal of the microbial fuel cell shows a small increment relative to the background reference signal due to the low content of biodegradable organic matter. , , or The level is relatively low. When domestic sewage, contaminated backflow liquid, or other liquids with high organic pollution loads enter the underground pipe gallery, the real-time output signal of the microbial fuel cell increases significantly relative to the background reference signal. , , or Increase. The system makes a judgment based on the preset normalized warning threshold, and when the normalized response value increases... or When the normalized warning threshold is reached or exceeded, the anti-shake timing is activated. The anti-shake timing will only be activated when the normalized response value continuously reaches or exceeds the normalized warning threshold for a duration that meets the preset anti-shake duration. The system generates a pollution warning only at that time. By using normalized response quantities as the criterion, the baseline deviation caused by differences in biofilm state, electrode aging, temperature changes, and installation environment between different microbial fuel cell units can be effectively reduced, making the warning criteria more consistent and comparable across different nodes.

[0062] It should be noted that the normalized early warning threshold is set in a similar way to the aforementioned early warning threshold, and is calculated based on the background reference signal and abnormal response signal before commissioning or during the on-site commissioning phase.

[0063] It should be noted that when or When the value is below the preset minimum baseline, normalization calculation is no longer performed, and the absolute response increment is used directly. or This serves as a basis for judgment, in order to avoid numerical anomalies at zero baseline values.

[0064] This normalized response eliminates baseline deviations caused by biofilm conditions, electrode aging, and temperature changes in different transducers, ensuring consistency of early warning criteria across different monitoring locations and environments, and effectively overcoming the impact of complex underground utility tunnel conditions on signal accuracy.

[0065] In some embodiments, after generating a pollution warning for the underground utility tunnel, the method further includes: generating a high-level digital warning signal based on the pollution warning; triggering a local audible and visual alarm module to output an audible and visual alarm via the high-level digital warning signal; and / or waking up a low-power wireless communication module to remotely upload the warning information to the monitoring backend. Specifically, based on the pollution warning, the comparator outputs a high-level digital signal, denoted as "1". This high-level digital warning signal is not directly generated by the microbial fuel cell to a standard logic level, but is generated by filtering, amplifying, threshold comparing, and hysteresis determining the weak analog signal output by the microbial fuel cell, thereby forming a 0 / 1 digital signal that can be recognized by a microcontroller, a switch input terminal, or a communication module. This high-level digital warning signal can directly trigger the local audible and visual alarm module to output an audible and visual alarm, for example, driving a buzzer to sound an alarm, illuminating a warning light, or activating other on-site alarm devices, so that inspection personnel or nearby staff can be promptly informed of the abnormal situation. Simultaneously or alternatively, the high-level digital warning signal can also wake up the low-power wireless communication module to remotely upload the warning information to the monitoring backend. For actions with high instantaneous power consumption, such as wireless communication and local audible and visual alarms, the system employs a pulsed or intermittent operating mode after energy storage, rather than being directly and continuously powered by the microbial fuel cell array. That is, the energy storage module first accumulates electrical energy, and then releases it to support the instantaneous completion of these high-power actions when an alarm or report is triggered. This allows for local alarm and remote reporting functions without relying on a continuous external power supply. Therefore, a digital signal of "0" output by the system indicates that no high organic pollution load has been detected or the warning level has not been reached, while a digital signal of "1" indicates that abnormal liquid with a high organic pollution load has been detected and an alarm has been triggered.

[0066] In a preferred embodiment, the warning output method is not limited to high and low level output, but can also be implemented in the form of pulse output, switch output, relay trigger signal or wireless trigger signal.

[0067] In a preferred embodiment, the system can set two threshold levels. The first threshold level is used to identify the entry of ordinary liquids or a slightly abnormal state, and the second threshold level is used to identify liquids with a high organic pollution load. When the output signal of the microbial fuel cell is lower than the first threshold level, the system determines that there is no abnormality or a low organic load state; when the output signal is between the first and second threshold levels, the system determines that it is a suspected abnormal state, and can increase the sampling frequency or enter a pending confirmation state; when the output signal exceeds the second threshold level and continues to exceed the anti-jitter duration, the system determines that it is an abnormal liquid with a high organic pollution load and outputs a digital warning signal "1". Through this graded threshold method, this application can not only determine whether there is liquid in the underground pipe gallery, but also further identify whether the liquid belongs to sewage or polluted liquid with a high organic pollution load based on whether the output signal of the microbial fuel cell reaches the organic pollution load threshold.

[0068] Through the above method, this application establishes a correspondence between "changes in organic matter content—enhanced microbial metabolism—enhanced electron transfer—increased output signal from the microbial fuel cell—threshold comparison—digital early warning output." A digital signal of "0" output by the system indicates that no high organic pollution load was detected or the warning level was not reached, while a digital signal of "1" indicates that abnormal liquid with a high organic pollution load was detected and an alarm was triggered. Therefore, this application can not only identify the presence of liquids in underground utility tunnels, but also further distinguish between ordinary seepage and clear water liquids and domestic sewage, polluted backflow liquids, or other liquids with high organic pollution loads based on the bioelectrochemical response of the microbial fuel cell to biodegradable organic matter.

[0069] This system generates a high-level digital signal upon confirmation of pollution, directly triggering audible and visual alarms and remote reporting via wireless communication modules. This enables linkage between local warnings and remote notifications, overcoming the limitations of the enclosed environment of underground utility tunnels on signal transmission and ensuring reliable transmission and timely handling of early warning information.

[0070] This application achieves in-situ calibration for different underground utility tunnel monitoring points by collecting the output signals of the transducer when it comes into contact with the first type of liquid (background liquid) and the second type of liquid (response liquid) and setting early warning thresholds and reset thresholds accordingly. This effectively eliminates baseline drift caused by electrode aging, fluctuations in biofilm activity, and changes in temperature and humidity, laying the foundation for establishing a reliable discrimination benchmark in harsh, humid, and highly fluctuating utility tunnel environments. Furthermore, by introducing a comparison mechanism between the energy storage unit's terminal voltage and the early warning threshold, it ensures that the back-end signal processing circuit only initiates signal processing when energy storage is sufficient. This approach avoids malfunctions in comparators or amplifiers due to insufficient power supply, thus ensuring the reliability of the early warning action. Furthermore, by comparing the target output signal with both the early warning threshold and the reset threshold, and by introducing a jitter reduction period to statistically analyze and determine the duration exceeding the early warning threshold, an early warning is triggered only when the signal consistently meets the standard and remains compliant at the end of the jitter reduction. This effectively filters out instantaneous spikes or noise glitches caused by liquid impact, electrode polarization, poor contact, and electromagnetic interference, preventing frequent false triggers and repeated jumps in alarm status near the threshold. These combined and progressively enhanced methods ensure that, even in special scenarios like underground utility tunnels with limited power supply and strong interference, this application can accurately identify abnormal liquid intrusion events with high organic pollution loads, significantly reducing the risk of missed and false alarms.

[0071] Based on the above method embodiments, corresponding apparatus embodiments are provided; One embodiment of this application provides a pollution early warning system based on microbial fuel cells, including: a microbial fuel cell transducer, installed at a monitoring point in an underground utility tunnel of a power grid, the microbial fuel cell transducer including a reactor shell, an anode disposed within the shell, an air cathode disposed on the shell, and a microbial membrane attached to the surface of the anode; An energy storage unit, wherein the power input terminal of the energy storage unit is connected to the power output terminal of the microbial fuel cell transducer, is used to collect and store the power generated by the sensing unit during the power generation process; A wake-up control unit, the input terminal of which is connected to the voltage detection terminal of the energy storage unit; The signal conditioning unit has its signal input terminal connected to the signal output terminal of the microbial fuel cell transducer, and its control terminal connected to the output terminal of the wake-up control unit.

[0072] It should be noted that the wake-up control unit can be implemented using a low-power voltage comparator. Its inverting input is connected to the terminal voltage sampling signal of the energy storage unit, and its non-inverting input is connected to the wake-up voltage threshold provided by the reference voltage source. When the terminal voltage sampling signal is higher than the reference voltage, the comparator outputs a wake-up signal to control the load switch to turn on, so that the signal conditioning unit can be powered on and put into operation.

[0073] Furthermore, the reactor shell is made of an insulating and corrosion-resistant material. The anode is a graphite rod, carbon felt, carbon brush, or carbon cloth disposed within the shell. The air cathode is disposed on the open side or sidewall of the shell, and the air cathode includes a conductive substrate and a catalytic conductive layer disposed on the surface of the conductive substrate. A porous ceramic sleeve is disposed around the anode between the anode and the cathode to prevent physical short circuits between the anode and the cathode and to provide an attachment support interface for the microbial membrane. The microbial membrane is an anode biofilm formed by the domestication of a mixed microbial community derived from activated sludge from a wastewater treatment system or sediment from a drainage ditch. The biofilm contains electroactive microorganisms with extracellular electron transfer capabilities.

[0074] It is understood that the above-described device embodiments correspond to the method embodiments of this application, and can realize the pollution early warning method based on microbial fuel cells provided by any of the above-described method embodiments of this application.

[0075] It should be noted that the device embodiments described above are merely illustrative, and some or all of the modules can be selected to achieve the purpose of this embodiment according to actual needs. Furthermore, in the accompanying drawings of the device embodiments provided in this application, the connection relationships between modules indicate that they have communication connections, which can specifically be implemented as one or more communication buses or signal lines. Those skilled in the art can understand and implement this without any creative effort.

[0076] Based on the above embodiments of the pollution early warning method based on microbial fuel cells, another embodiment of this application provides a terminal device, which includes a processor, a memory, and a computer program stored in the memory and configured to be executed by the processor. When the processor executes the computer program, it implements the pollution early warning method based on microbial fuel cells of any embodiment of this application.

[0077] For example, in this embodiment, the computer program can be divided into one or more modules, which are stored in the memory and executed by the processor to complete this application. The one or more module units may be a series of computer program instruction segments capable of performing a specific function, which describe the execution process of the computer program in the terminal device.

[0078] The terminal device may be a desktop computer, laptop, handheld computer, or cloud server, etc. The terminal device may include, but is not limited to, a processor and a memory.

[0079] The processor can be a Central Processing Unit (CPU), or other general-purpose processors, digital signal processors (DSPs), application-specific integrated circuits (ASICs), field-programmable gate arrays (FPGAs), or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, etc. A general-purpose processor can be a microprocessor or any conventional processor. The processor is the control center of the terminal device, connecting all parts of the terminal device via various interfaces and lines.

[0080] Based on the above-described method embodiments, another embodiment of this application provides a computer-readable storage medium including a stored computer program, wherein, when the computer program is executed, it controls the device where the computer-readable storage medium is located to execute the pollution early warning method based on microbial fuel cells described in any of the above-described method embodiments of this application.

[0081] The modules / units integrated in the device / terminal equipment, if implemented as software functional units and sold or used as independent products, can be stored in a computer-readable storage medium. Based on this understanding, all or part of the processes in the methods of the above embodiments can also be implemented by a computer program instructing related hardware. The computer program can be stored in a computer-readable storage medium, and when executed by a processor, it can implement the steps of the various method embodiments described above. The computer program includes computer program code, which can be in the form of source code, object code, executable files, or certain intermediate forms. The computer-readable medium can include: any entity or device capable of carrying the computer program code, recording media, USB flash drives, portable hard drives, magnetic disks, optical disks, computer memory, read-only memory (ROM), random access memory (RAM), electrical carrier signals, telecommunication signals, and software distribution media, etc.

[0082] The above description is the preferred embodiment of this application. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the principle of this application, and these improvements and modifications are also considered to be within the scope of protection of this application.

Claims

1. A pollution early warning method based on microbial fuel cells, characterized in that, include: The background output signal of the microbial fuel cell transducer installed at the monitoring point of the underground utility tunnel of the power grid is collected when it comes into contact with the first type of liquid and the response output signal when it comes into contact with the second type of liquid. Based on the background output signal and the response output signal, a warning threshold and a reset threshold are set. The real-time output electrical signal generated by the microbial fuel cell transducer at the monitoring point of the underground pipe gallery when it comes into contact with the liquid to be tested is obtained, and the current terminal voltage value of the energy storage unit that provides power to the back-end signal processing circuit of the transducer is obtained. The current terminal voltage value is compared with a preset wake-up voltage threshold. If the current terminal voltage value reaches or exceeds the wake-up voltage threshold, the real-time output electrical signal is processed to obtain the target output signal. The target output signal is compared with the warning threshold and the reset threshold respectively. When the target output signal reaches or exceeds the warning threshold, the duration of exceeding the warning threshold is counted. When the duration reaches the preset anti-jitter duration and the target output signal still reaches or exceeds the warning threshold at the end of the anti-jitter duration, a pollution warning for the underground utility tunnel of the power grid is generated.

2. The pollution early warning method based on microbial fuel cells according to claim 1, characterized in that, The step of setting the warning threshold and reset threshold based on the background output signal and the response output signal includes: Calculate the difference between the response output signal and the background output signal; Calculate the product of the difference and the preset threshold adjustment coefficient, and determine the warning threshold based on the background output signal and the product; A reset threshold for determining the falling edge of the signal is set according to the warning threshold, wherein the reset threshold is lower than the warning threshold and higher than the background output signal.

3. The pollution early warning method based on microbial fuel cells according to claim 1, characterized in that, Also includes: If the current terminal voltage value is lower than the wake-up voltage threshold, the energy storage unit is determined to be in a low-energy state, and the back-end signal processing circuit is controlled to maintain a power-off sleep state.

4. The pollution early warning method based on microbial fuel cells according to claim 1, characterized in that, The process of processing the real-time output electrical signal to obtain the target output signal includes: The real-time output electrical signal is subjected to low-pass filtering to remove high-frequency noise and transient disturbances, resulting in a processed signal; The processed signal is amplified using low-power amplification to a level range recognizable by the comparator, thereby obtaining the target output signal.

5. The pollution early warning method based on microbial fuel cells according to claim 1, characterized in that, After the duration of the statistical data exceeding the warning threshold is reached, the following is also included: If, within the preset anti-shake duration, the target output signal falls below the reset threshold and continues for more than the preset reset time, the currently recorded duration is cleared and the timing is reset. The timing restarts when the target output signal reaches or exceeds the warning threshold again.

6. The pollution early warning method based on microbial fuel cells according to claim 1, characterized in that, After comparing the target output signal with the warning threshold and the reset threshold respectively, the method further includes: When the target output signal is below the reset threshold, it is determined that the liquid under test has not met the warning conditions, and the state of no warning is maintained.

7. The pollution early warning method based on microbial fuel cells according to any one of claims 1-6, characterized in that, Also includes: Calculate the response increment of the real-time output electrical signal relative to the background output signal; Divide the response increment by the background output signal to obtain the normalized response quantity; The normalized response quantity is compared with a preset normalized warning threshold. When the normalized response quantity reaches or exceeds the normalized warning threshold and the duration reaches the anti-shake duration, the pollution warning is generated.

8. The pollution early warning method based on microbial fuel cells according to any one of claims 1-6, characterized in that, Following the generation of pollution warnings for underground utility tunnels in the power grid, the following is also included: A high-level digital warning signal is generated based on the pollution warning. The high-level digital warning signal triggers the local audible and visual alarm module to output an audible and visual alarm, and / or wakes up the low-power wireless communication module to remotely upload the warning information to the monitoring backend.

9. A pollution early warning system based on microbial fuel cells, characterized in that, include: A microbial fuel cell transducer is installed at a monitoring point in an underground utility tunnel of a power grid. The microbial fuel cell transducer includes a reactor shell, an anode disposed inside the shell, an air cathode disposed on the shell, and a microbial membrane attached to the surface of the anode. An energy storage unit, wherein the power input terminal of the energy storage unit is connected to the power output terminal of the microbial fuel cell transducer, is used to collect and store the power generated by the sensing unit during the power generation process; A wake-up control unit, the input terminal of which is connected to the voltage detection terminal of the energy storage unit; The signal conditioning unit has its signal input terminal connected to the signal output terminal of the microbial fuel cell transducer, and its control terminal connected to the output terminal of the wake-up control unit.

10. The pollution early warning system based on microbial fuel cells according to claim 9, characterized in that, The reactor shell is made of insulating and corrosion-resistant material. The anode is a graphite rod, carbon felt, carbon brush, or carbon cloth disposed within the shell. The air cathode is disposed on the open side or sidewall of the shell and includes a conductive substrate and a catalytic conductive layer disposed on the surface of the conductive substrate. A porous ceramic sleeve is disposed around the anode between the anode and the cathode to prevent physical short circuit between the anode and the cathode and to provide an attachment support interface for the microbial biofilm. The microbial biofilm is an anode biofilm formed by the domestication of a mixed microbial community derived from activated sludge from a wastewater treatment system or sediment from a drainage ditch. The biofilm contains electroactive microorganisms with extracellular electron transfer capabilities.

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