A low-temperature-resistant artificial wetland wastewater advanced treatment system and method

Abstract

The application discloses a kind of low-temperature resistant constructed wetland wastewater advanced treatment system in the field of sewage treatment, comprising: fuel cell component, including reaction cylinder and the water passing assembly connected in vertical cylinder, reaction cylinder is sequentially provided with upper support layer, cathode layer, isolation layer, anode layer and lower support layer from top to bottom in it, and the conductive circuit is connected out in anode layer and cathode layer, adjustable resistance is provided on the conductive circuit;Environment module is arranged in reaction cylinder, and environment module is used to monitor temperature, pH value, dissolved oxygen and oxidation-reduction potential data in reaction cylinder;Controller is electrically connected with environment module, adjustable resistance and water passing assembly;And a kind of control method;The beneficial effects of the application are that: by setting environment module, controller and energy recovery component, the system can be more suitable for the treatment of wastewater in low temperature environment, and the external energy consumption of the system is reduced, the utilization rate of its own output energy is improved, energy saving and environmental protection.

Description

Technical Field

[0001] This invention relates to the field of wastewater treatment, specifically to a low-temperature resistant constructed wetland wastewater deep treatment system and method. Background Technology

[0002] With the acceleration of urbanization, the number of wastewater treatment plants being built is constantly increasing. However, pollutants such as nitrogen remaining in the effluent from these plants still pose a threat to the aquatic environment, causing problems such as eutrophication and ecological imbalance. Constructed wetlands (CWs), as a highly efficient and cost-effective wastewater treatment technology, are widely used for the advanced treatment of wastewater effluent from wastewater treatment plants. However, their denitrification performance is limited in low-temperature environments, leading to a significant decrease in nitrogen removal efficiency and restricting their application in cold regions.

[0003] Constructed wetland microbial fuel cell (CWMFC) technology, as an emerging wastewater treatment technology, has the dual advantages of energy recovery and pollutant removal. However, most existing CWMFCs lack self-regulation capabilities under low-temperature conditions, resulting in a decrease in wastewater treatment efficiency in cold environments.

[0004] Therefore, we propose a low-temperature resistant constructed wetland wastewater deep treatment system and method. Summary of the Invention

[0005] To address the aforementioned shortcomings of existing technologies, this invention provides a low-temperature resistant constructed wetland wastewater deep treatment system and method to solve the problems of insufficient pollutant removal and power generation efficiency when treating black and odorous water bodies using constructed wetlands-microbial fuel cells.

[0006] To achieve the above-mentioned objectives, the technical solution adopted by this invention is as follows:

[0007] A low-temperature resistant constructed wetland wastewater deep treatment system includes:

[0008] The fuel cell assembly includes a reaction chamber and a water supply assembly connected to the reaction chamber. The reaction chamber is provided with an upper support layer, a cathode layer, an isolation layer, an anode layer and a lower support layer from top to bottom. The water supply assembly is used to input wastewater into the reaction chamber and to discharge treated wastewater from the reaction chamber. Conductive circuits are connected out of the anode layer and the cathode layer, and adjustable resistors are provided on the conductive circuits.

[0009] An environmental module, located inside the reaction chamber, is used to monitor the temperature, pH value, dissolved oxygen, and redox potential data inside the reaction chamber.

[0010] The controller, environmental module, adjustable resistor, and water supply components are all electrically connected.

[0011] By setting up a controller, which receives temperature, pH, dissolved oxygen, and oxidation-reduction potential data monitored by the environmental module, the controller determines whether the oxidation-reduction reaction inside the reaction tank is normal. If the internal oxidation-reduction reaction is abnormal, the controller controls the resistance of the adjustable resistor to reduce its resistance and increase the current intensity to stimulate the metabolic activity of the internal microorganisms. At the same time, it reduces the water flow rate of the water circulation components, prolongs the residence time of sewage in the reaction tank, and improves the sewage treatment effect. Through automatic adjustment by the controller, this system can better adapt to sewage treatment operations at low temperatures.

[0012] Further, it also includes an energy recovery component, which is connected to the conduction circuit to recover and release electrical energy. The energy recovery component is electrically connected to the controller. By setting up the energy recovery component, the electrical energy produced by the fuel cell assembly can be recovered and reused, reducing energy consumption in wastewater treatment.

[0013] Further specified, the upper support layer is filled with zeolite, the cathode layer is filled with pyrite, the isolation layer is filled with gravel, the anode layer is filled with sponge iron, the lower support layer is filled with gravel, and the upper support layer is planted with low-temperature resistant plants.

[0014] Wastewater flows into the lower support layer and then into the anode layer. In the anode layer, electroactive microorganisms utilize the carbon source in the wastewater to generate electrons, promoting the generation of current. Simultaneously, sponge iron is oxidized to generate electrons, further enhancing the generated current. The generated electrons flow through the conduction circuit and enter the cathode layer, where they are utilized by electroactive bacteria, promoting the removal of nitrates by electroactive denitrifying bacteria. Furthermore, sponge iron is oxidized into ferrous iron by iron-oxidizing microorganisms, which may then be utilized by autotrophic denitrifying bacteria, forming an autotrophic denitrification process that enhances nitrogen removal. Additionally, sponge iron can be oxidized into ferric iron by iron-oxidizing microorganisms, and then reduced back to ferrous iron by iron-reducing bacteria, forming an iron cycle process that further improves nitrogen removal efficiency.

[0015] Further specified, the reaction cylinder wall corresponding to the lower support layer is provided with a water inlet pipe, the reaction cylinder wall corresponding to the upper support layer is provided with a water outlet pipe, the water circulation assembly includes a water pump, the water outlet end of the water pump is connected to the water inlet pipe, the water inlet end is placed in the sewage tank, and the water pump and the controller are electrically connected.

[0016] Further specifying, the environmental module includes a temperature sensor, a pH sensor, a dissolved oxygen sensor, and an electrode sensor; the temperature sensor, pH sensor, dissolved oxygen sensor, and electrode sensor are all electrically connected to the controller.

[0017] Further specified, a cathode electrode is provided in the cathode layer, and an anode electrode is provided in the anode layer. The cathode electrode and the anode electrode are respectively connected to the two ends of the conduction circuit. Two electrode sensors are provided, which are respectively located near the cathode electrode and the anode electrode in the reaction vessel. The pH sensor, dissolved oxygen sensor and temperature sensor are all embedded in the anode layer.

[0018] Further specifying, the anode electrode is made of graphite, and the cathode electrode is made of activated carbon. Both the anode and cathode electrodes are mesh-like. Setting both the anode and cathode electrodes as mesh-like can increase the contact area between the electrodes and the wastewater, thereby improving the efficiency of current generation and transmission.

[0019] Further defining the energy recovery component, it includes a supercapacitor module, an external power supply, and a power switching module. The supercapacitor module is used to store the excess current generated by the fuel cell assembly, the external power supply is used to provide initial startup power to the controller, and the power switching module is used to switch the power supply of the water pump between the external power supply, the fuel cell assembly, and the supercapacitor module based on the electrical energy data generated by the fuel cell assembly.

[0020] When the system starts up, it is powered by an external power source. A water pump drives wastewater into the fuel cell assembly, which generates current. The power switching module monitors the current generated. If the current is sufficient to drive the system, the power supply is switched from the external power source to the fuel cell assembly. Excess electrical energy generated by the fuel cell assembly is stored in the supercapacitor module. When the current generated by the fuel cell assembly is insufficient to power the system, the power supply is switched to the supercapacitor module. When the power supply from the supercapacitor module is insufficient, the power supply is switched back to the external power source. This improves the energy utilization rate of the fuel cell assembly and reduces external energy consumption.

[0021] A control method for controlling the aforementioned low-temperature resistant constructed wetland wastewater deep treatment system includes the following steps:

[0022] S1. During system startup, an external power supply provides power to the system. The output power of the external power supply is... At this point, the water pump starts to transport wastewater to the fuel cell assembly, and the fuel cell assembly begins to generate electricity. The normal power output of the water pump at this time is... The system power consumption is The charging power of the supercapacitor module is At this time, the normal resistance value of the adjustable resistor is The current through the adjustable resistor is Voltage is :

[0023]

[0024] S2. When the power switching module detects that the current and voltage generated by the fuel cell assembly have reached the power supply standard, the controller controls the power switching module to switch the system's power supply to the fuel cell assembly and charge the supercapacitor module. The power supply standard is as follows:

[0025]

[0026] S3. When the electricity generated by the fuel cell assembly is insufficient to charge the supercapacitor module:

[0027]

[0028] The controller lowers the resistance of the adjustable resistor to... Reduce the power of the water pump to [value missing]. To keep the fuel cell assembly charging the supercapacitor module and to allow current to flow through an adjustable resistor. ,Voltage satisfy:

[0029]

[0030] S4. Collect current environmental parameters;

[0031] If the environmental parameters are abnormal, it indicates that the power output reduction of the fuel cell assembly is caused by changes in the environmental parameters within the fuel cell assembly, and proceed to step S5.

[0032] If the environmental parameters return to normal, it indicates that the power output reduction of the fuel cell assembly is due to the lifespan reduction of the fuel cell assembly, and proceed to step S6.

[0033] S5. Continue executing step S3, and when the environmental parameters return to normal, return to step S2 and adjust the adjustable resistor to its normal value. And adjust the power of the water pump to normal power. If the environmental parameters are still abnormal, proceed to step S6.

[0034] S6. Keep the adjustable resistor value set to low. The power of the water pump is This enables the fuel cell assembly to charge the supercapacitor module;

[0035] S7. Until due to the degradation of the fuel cell components' lifespan... The power switching module switches the system power supply to the supercapacitor module, which then powers the system, and satisfies the following conditions: ;

[0036] S8. If step S7 is achieved sequentially through steps S4, S5, and S6, and this is achieved during the continuous discharge of the supercapacitor module. If the environmental parameters are still abnormal, the system power supply will be switched to an external power supply to power the system, and step S10 will be performed.

[0037] If the supercapacitor module is in the process of continuous discharge... If the environmental parameters have returned to normal, return to step S2;

[0038] S9. If step S7 is achieved sequentially through steps S4 and S6, then the supercapacitor module will reach its target during continuous discharge. When the power switching module switches to an external power supply to power the system, step S10 is performed;

[0039] S10. If the external power supply switched in step S8 supplies power to the system, and the environmental parameters are still abnormal after the set duration of continuous power supply, then manually turn off the power and stop the system; if the external power supply supplies power to the system, and the environmental parameters return to normal within the set duration of continuous power supply, then return to step S2.

[0040] If the system is powered by the external power source switched in step S9, the system should be manually powered off immediately, the internal components of the fuel cell assembly should be maintained and replaced, and then the system should be restarted to return to step S1.

[0041] Further, the abnormality of environmental parameters in any step S4-S10 is specifically determined as follows: if at least one of the four data points of temperature, pH value, dissolved oxygen and redox potential detected by the environmental module is outside the set normal range, the environmental parameter is determined to be abnormal; if all four data points of temperature, pH value, dissolved oxygen and redox potential detected by the environmental module are within the set normal range, the environmental parameter is determined to be normal.

[0042] The beneficial effects of this invention are as follows: by setting up an environmental module, a controller, and an energy recovery component, the system can better adapt to the treatment of wastewater in low-temperature environments, and the external energy consumption of the system is reduced, while the utilization rate of its own produced energy is improved, thus saving energy and protecting the environment. Attached Figure Description

[0043] Figure 1 This is a simplified structural diagram of the present invention;

[0044] Figure 2 This is a diagram showing the connection relationships of the electrical components in this invention;

[0045] Figure 3 This is a comparison image of wastewater treatment before and after the present invention.

[0046] The symbols for each component are as follows:

[0047] Fuel cell assembly 1, upper support layer 11, water outlet pipe 111, low-temperature resistant plant 112, cathode layer 12, cathode electrode 121, isolation layer 13, anode layer 14, anode electrode 141, lower support layer 15, water inlet pipe 151, water pump 16, conduction circuit 17, adjustable resistor 18, environmental module 2, temperature sensor 21, pH sensor 22, dissolved oxygen sensor 23, electrode sensor 24, controller 3, energy recovery assembly 4, supercapacitor module 41, external power supply 42, power switching module 43. Detailed Implementation

[0048] The specific embodiments of the present invention are described below to enable those skilled in the art to understand the present invention. However, it should be understood that the present invention is not limited to the scope of the specific embodiments. For those skilled in the art, various changes are obvious as long as they are within the spirit and scope of the present invention as defined and determined by the appended claims. All inventions utilizing the concept of the present invention are protected.

[0049] Example:

[0050] like Figures 1-2As shown, a low-temperature resistant constructed wetland wastewater deep treatment system includes a fuel cell assembly 1, an environmental module 2, a controller 3, and an energy recovery assembly 4. The fuel cell assembly 1 includes a reaction cylinder and a water-passing assembly connected to the reaction cylinder. The reaction cylinder contains, from top to bottom, an upper support layer 11, a cathode layer 12, an isolation layer 13, an anode layer 14, and a lower support layer 15. The water-passing assembly is used to input wastewater into the reaction cylinder and to discharge treated wastewater from the reaction cylinder. The anode layer 14 and the cathode layer 15... A conductive circuit 17 extends from layer 12, and an adjustable resistor 18 is installed on the conductive circuit 17. The adjustable resistor 18 is electrically connected to the controller 3 through the conductive circuit 17. The upper support layer 11 is filled with zeolite with a particle size of 6-8 mm, the cathode layer 12 is filled with pyrite with a particle size of 4-6 mm, the isolation layer 13 is filled with gravel with a particle size of 5-8 mm, the anode layer 14 is filled with sponge iron with a particle size of 3-6 mm, and the lower support layer 15 is filled with gravel with a particle size of 5-8 mm. The support layer 11 is planted with low-temperature resistant plants 112, namely Siberian iris. The upper support layer 11 is 5 cm thick, the cathode layer 12 is 21 cm thick, the isolation layer 13 is 6 cm thick, the anode layer 14 is 22 cm thick, and the lower support layer 15 is 5 cm thick. A water inlet pipe 151 is provided on the reaction cylinder wall corresponding to the lower support layer 15, and a water outlet pipe 111 is provided on the reaction cylinder wall corresponding to the upper support layer 11. The water circulation assembly includes a water pump. 16. The outlet end of the water pump 16 is connected to the inlet pipe 151, and the inlet end is placed in the sewage tank. The water pump 16 is electrically connected to the controller 3. The cathode layer 12 is provided with a cathode electrode 121, and the anode layer 14 is provided with an anode electrode 141. The cathode electrode 121 and the anode electrode 141 are respectively connected to the two ends of the conduction circuit 17. The anode electrode 141 is made of graphite material, and the cathode electrode 121 is made of activated carbon material. Both the anode electrode 141 and the cathode electrode 121 are in the shape of a mesh plate.

[0051] The environmental module 2 is used to monitor the temperature, pH value, dissolved oxygen, and redox potential data inside the reaction vessel. The environmental module 2 includes a temperature sensor 21, a pH sensor 22, a dissolved oxygen sensor 23, and an electrode sensor 24. The temperature sensor 21, pH sensor 22, dissolved oxygen sensor 23, and electrode sensor 24 are all electrically connected to the controller 3. There are two electrode sensors 24, which are located inside the reaction vessel near the cathode electrode 121 and the anode electrode 141, respectively. The pH sensor 22, dissolved oxygen sensor 23, and temperature sensor 21 are all embedded in the anode layer 14.

[0052] The energy recovery component 4 is connected to the conduction circuit 17 to recover and release electrical energy. The energy recovery component 4 includes a supercapacitor module 41, an external power supply 42, and a power switching module 43. The external power supply 42, anode electrode 141, cathode electrode 121, supercapacitor module 41, controller 3, water pump 16, temperature sensor 21, pH sensor 22, dissolved oxygen sensor 23, and electrode sensor 24 are all electrically connected to the power switching module 43. The supercapacitor module 41 is used to store the excess current generated by the fuel cell assembly 1. The external power supply 42 is used to provide initial start-up power to the controller 3. The power switching module 43 is used to switch the power supply of the water pump 16 between the external power supply 42, the fuel cell assembly 1, and the supercapacitor module 41 according to the electrical energy data generated by the fuel cell assembly 1.

[0053] In this embodiment, the external power supply 42 uses an Anker 737, the supercapacitor module 41 uses a Panasonic EEC-E501D01, the controller 3 uses an Arduino Uno R3, the water pump 16 uses a Newark 207-1045, the temperature sensor 21 uses a DS18B20, the pH sensor 22 uses a pH-BT520, the dissolved oxygen sensor 23 uses an Optodes DO200, the electrode sensor 24 uses a Sensorex ORP250, the power switching module 43 uses a Texas Instruments TPS25982, and the adjustable resistor 18 uses a Texas Instruments DAC8830. A Wi-Fi or Bluetooth module can also be added to transmit data to other terminals for viewing and setting various parameters, enabling remote system monitoring.

[0054] By setting up a controller 3, which receives temperature, pH, dissolved oxygen, and oxidation-reduction potential data monitored by the environmental module 2, the controller 3 determines whether the oxidation-reduction reaction in the reaction tank is normal. If the internal oxidation-reduction reaction is abnormal, the controller controls the resistance of the adjustable resistor 18 to reduce its resistance and increase the current intensity, thereby stimulating the metabolic activity of the internal microorganisms and simultaneously reducing the water flow rate of the water circulation component to prolong the residence time of sewage in the reaction tank and improve the sewage treatment effect. The controller 3 automatically adjusts the system to better adapt to sewage treatment operations at low temperatures. By setting up an energy recovery component 4, the electrical energy generated by the fuel cell component 1 can be recovered and utilized, reducing energy consumption in sewage treatment. Sewage flows into the lower support layer 15 and enters the anode layer 14. In the anode layer 14, electroactive microorganisms use the carbon source in the sewage to generate electrons, promoting the generation of current. At the same time, the sponge iron is oxidized to generate electrons, further enhancing the generated current. The generated electrons flow through the conduction circuit 17 and enter the cathode layer 12, where they are utilized by the electroactive bacteria to promote the removal of nitrates by electroactive denitrifying bacteria. Furthermore, the sponge iron is oxidized by iron microorganisms. Biological oxidation produces ferrous iron (Fe2+), which can then be utilized by autotrophic denitrifying bacteria, forming an autotrophic denitrification process that enhances nitrogen removal. Simultaneously, sponge iron can be oxidized to ferric iron (Fe3+) by iron-oxidizing microorganisms, and then reduced back to ferrous iron (Fe2+) by iron-reducing bacteria, forming an iron cycle that further improves nitrogen removal efficiency. Setting both the anode electrode 141 and the cathode electrode 121 in a mesh shape increases the contact area between the electrodes and the wastewater, improving current generation and transmission efficiency. During system startup, the external power supply 42 drives the system, and the water pump 16 pumps wastewater into the fuel cell assembly 1, where it is burned. When the fuel cell assembly 1 generates current, the power switching module 43 monitors the generated current. If the generated current is sufficient to drive the system, the power supply from the external power supply 42 is switched to the power supply from the fuel cell assembly 1. Excess electrical energy generated by the fuel cell assembly 1 is stored in the supercapacitor module 41. When the current generated by the fuel cell assembly 1 is insufficient to power the system, the power supply from the system is switched to the supercapacitor module 41. When the power supply from the supercapacitor module 41 is insufficient, the power supply is switched back to the external power supply 42. This improves the energy utilization rate of the fuel cell assembly 1 and reduces external energy consumption.

[0055] A control method for controlling the aforementioned low-temperature resistant constructed wetland wastewater deep treatment system includes the following steps:

[0056] S1. When the system starts up, the external power supply 42 supplies power to the system, and the output power of the external power supply 42 is... At this time, water pump 16 starts to transport sewage to fuel cell assembly 1, and fuel cell assembly 1 begins to generate electricity. The normal power output of water pump 16 at this time is... The system power consumption is The charging power of the supercapacitor module 41 is At this time, the normal resistance value of adjustable resistor 18 is The current through the adjustable resistor 18 is Voltage is :

[0057]

[0058] S2. When the power switching module 43 monitors that the current and voltage generated by the fuel cell assembly 1 reach the power supply standard, the controller 3 controls the power switching module 43 to switch the system's power supply to the fuel cell assembly 1 and charge the supercapacitor module 41. The power supply standard is as follows:

[0059]

[0060] S3. When the electricity generated by fuel cell assembly 1 is insufficient to charge supercapacitor module 41:

[0061]

[0062] Controller 3 lowers the resistance of adjustable resistor 18 to Reduce the power of water pump 16 to To keep the fuel cell assembly 1 charging the supercapacitor module 41, and through the current of the adjustable resistor 18. ,Voltage satisfy:

[0063]

[0064] S4. Collect current environmental parameters;

[0065] If the environmental parameters are abnormal, it indicates that the power supply reduction of fuel cell assembly 1 is caused by the change of environmental parameters inside fuel cell assembly 1, and proceed to step S5.

[0066] If the environmental parameters return to normal, it indicates that the power output reduction of fuel cell component 1 is due to the lifespan reduction of fuel cell component 1, and proceed to step S6.

[0067] S5. Continue executing step S3, and when the environmental parameters return to normal, return to step S2 and adjust the resistance of adjustable resistor 18 to the normal resistance value. Adjust the power of water pump 16 to its normal power. If the environmental parameters are still abnormal, proceed to step S6.

[0068] S6. Keep the resistance of adjustable resistor 18 at a low value. The power of water pump 16 is This enables the fuel cell assembly 1 to charge the supercapacitor module 41;

[0069] S7. Until the lifespan of fuel cell assembly 1 degrades, leading to... The power switching module 43 switches the system power supply to the supercapacitor module 41, using the supercapacitor module 41 to power the system, and satisfies the following: ;

[0070] S8. If step S7 is achieved sequentially through steps S4, S5, and S6, and this is achieved during the continuous discharge process of the supercapacitor module 41. If the environmental parameters are still abnormal, the system power supply will be switched to the external power supply 42 to power the system, and step S10 will be performed.

[0071] If the supercapacitor module (41) is in the process of continuous discharge... If the environmental parameters have returned to normal, return to step S2;

[0072] S9. If step S7 is achieved sequentially through steps S4 and S6, then the supercapacitor module 41 will reach its target during continuous discharge. When the power switching module 43 switches to the external power supply 42 to power the system, step S10 is performed;

[0073] S10. If the external power supply 42 switched in step S8 supplies power to the system, and the environmental parameters are still abnormal after the set duration of continuous power supply, then manually turn off the power and stop the system; if the external power supply 42 supplies power to the system, and the environmental parameters return to normal within the set duration of continuous power supply, then return to step S2.

[0074] If the system is powered by the external power supply 42 switched in step S9, the system should be manually powered off immediately, the internal components of the fuel cell assembly 1 should be maintained and replaced, and then the system should be restarted to return to step S1.

[0075] The environmental parameter anomaly in any step S4-S10 is specifically determined as follows: if at least one of the four data points detected by the environmental module 2—temperature, pH, dissolved oxygen, and oxidation-reduction potential—is outside the set normal range, the environmental parameter is determined to be abnormal; if all four data points detected by the environmental module 2 are within the set normal range, the environmental parameter is determined to be normal. The system power consumption includes the operating power of the controller, the operating power of the environmental module, and the operating power of the power switching module.

[0076] like Figure 3 As shown, Figure 3This is a comparison chart of the wastewater before and after treatment by the low-temperature resistant constructed wetland wastewater deep treatment system of the present invention, which has been running continuously for 60 days. The chart shows that the nitrate concentration of the wastewater treated by the system decreased by about 80% each day compared to the wastewater before treatment, further verifying the ability of the low-temperature resistant constructed wetland wastewater deep treatment system of the present invention to treat nitrogen pollution in wastewater.

Claims

1. A control method for controlling a low-temperature resistant constructed wetland wastewater deep treatment system, the low-temperature resistant constructed wetland wastewater deep treatment system comprising: The fuel cell assembly (1) includes a reaction cylinder and a water supply assembly connected to the reaction cylinder. The reaction cylinder is provided with an upper support layer (11), a cathode layer (12), an isolation layer (13), an anode layer (14), and a lower support layer (15) from top to bottom. The water supply assembly is used to input wastewater into the reaction cylinder and to discharge treated wastewater from the reaction cylinder. A conductive circuit (17) is connected to the anode layer (14) and the cathode layer (12). An adjustable resistor (18) is provided on the conductive circuit (17). An environmental module (2) is located inside the reaction chamber. The environmental module (2) is used to monitor the temperature, pH value, dissolved oxygen and redox potential data inside the reaction chamber. The controller (3), environmental module (2), adjustable resistor (18), and water supply component are all electrically connected; It also includes an energy recovery component (4), which is connected to the conduction circuit (17) to recover and release electrical energy. The energy recovery component (4) and the controller (3) are electrically connected. The upper support layer (11) is filled with zeolite, the cathode layer (12) is filled with pyrite, the isolation layer (13) is filled with gravel, the anode layer (14) is filled with sponge iron, the lower support layer (15) is filled with gravel, and the upper support layer (11) is planted with low-temperature resistant plants (112). The lower support layer (15) is provided with an inlet pipe (151) on the wall of the reaction cylinder, and the upper support layer (11) is provided with an outlet pipe (111) on the wall of the reaction cylinder. The water supply assembly includes a water pump (16). The outlet end of the water pump (16) is connected to the inlet pipe (151), and the inlet end is placed in the sewage tank. The water pump (16) and the controller (3) are electrically connected. The energy recovery component (4) includes a supercapacitor module (41), an external power supply (42), and a power switching module (43). The supercapacitor module (41) is used to store the excess current generated by the fuel cell assembly (1). The external power supply (42) is used to provide initial start-up power to the controller (3). The power switching module (43) is used to switch the power supply of the water pump (16) between the external power supply (42), the fuel cell assembly (1), and the supercapacitor module (41) according to the electrical energy data generated by the fuel cell assembly (1). The control method is characterized by the following steps: S1. When the system starts, the external power supply (42) supplies power to the system, the output power of the external power supply (42) is At this time, the water pump (16) starts to transport sewage to the fuel cell assembly (1), and the fuel cell assembly (1) starts to work and generate electricity, at this time the normal power of the water pump (16) is , the power consumption of the system is , the charging power of the super capacitor module (41) is At this time, the normal resistance value of the adjustable resistor (18) is , the current passing through the adjustable resistor (18) is , the voltage is : S2. When the power switching module (43) monitors that the current and voltage generated by the fuel cell assembly (1) reach the power supply standard, the controller (3) controls the power switching module (43) to switch the system's power supply to the fuel cell assembly (1) and charge the supercapacitor module (41). The power supply standard is as follows: S3. When the amount of electricity generated by the fuel cell assembly (1) is insufficient to charge the supercapacitor module (41): The controller (3) lowers the resistance of the adjustable resistor (18) to [value missing]. Reduce the power of the water pump (16) to To keep the fuel cell assembly (1) charging the supercapacitor module (41) and through the current of the adjustable resistor (18) ,Voltage satisfy: S4. Collect current environmental parameters; If the environmental parameters are abnormal, it indicates that the power supply of the fuel cell assembly (1) is reduced due to the change in the environmental parameters inside the fuel cell assembly (1), and proceed to step S5. If the environmental parameters return to normal, it indicates that the power supply degradation of the fuel cell assembly (1) is caused by the life degradation of the fuel cell assembly (1), and proceed to step S6. S5. Continue executing step S3, and when the environmental parameters return to normal, return to step S2 and adjust the resistance of the adjustable resistor (18) to the normal resistance value. And adjust the power of the water pump (16) to the normal power. If the environmental parameters are still abnormal, proceed to step S6. S6. Keep the resistance of the adjustable resistor (18) adjusted to a low value. The power of the water pump (16) is This enables the fuel cell assembly (1) to charge the supercapacitor module (41); S7. Until the lifespan of the fuel cell assembly (1) degrades. The power switching module (43) switches the system power supply to the supercapacitor module (41), and uses the supercapacitor module (41) to supply power to the system, while satisfying the following: ; S8. If step S7 is achieved sequentially through steps S4, S5, and S6, and is achieved during the continuous discharge process of the supercapacitor module (41)... If the environmental parameters are still abnormal, the system power supply will be switched to the external power supply (42) to power the system, and step S10 will be performed. If the supercapacitor module (41) is in the process of continuous discharge... If the environmental parameters have returned to normal, return to step S2; S9. If step S7 is reached after steps S4 and S6 in sequence, then when the supercapacitor module (41) continues to discharge, the following steps are achieved: When the power switching module (43) switches to the external power supply (42) to power the system, step S10 is performed; S10. If the external power supply (42) switched in step S8 supplies power to the system, and the environmental parameters are still abnormal after the continuous power supply is set for a certain period of time, then manually turn off the power and stop the system; if the external power supply (42) supplies power to the system, and the environmental parameters return to normal within the continuous power supply is set for a certain period of time, then return to step S2. If the system is powered by the external power supply (42) switched in step S9, the system is immediately powered off manually, the fuel cell assembly (1) is maintained and replaced, and then the system is restarted to return to step S1.

2. The control method according to claim 1, characterized in that, The environmental module (2) includes a temperature sensor (21), a pH sensor (22), a dissolved oxygen sensor (23), and an electrode sensor (24); the temperature sensor (21), pH sensor (22), dissolved oxygen sensor (23), and electrode sensor (24) are all electrically connected to the controller (3).

3. The control method according to claim 2, characterized in that, The cathode layer (12) is provided with a cathode electrode (121), and the anode layer (14) is provided with an anode electrode (141). The cathode electrode (121) and the anode electrode (141) are respectively connected to the two ends of the conduction circuit (17). Two electrode sensors (24) are provided, which are respectively located near the cathode electrode (121) and the anode electrode (141) in the reaction vessel. The pH sensor (22), the dissolved oxygen sensor (23) and the temperature sensor (21) are all embedded in the anode layer (14).

4. The control method according to claim 3, characterized in that, The anode electrode (141) is made of graphite, and the cathode electrode (121) is made of activated carbon. Both the anode electrode (141) and the cathode electrode (121) are in the shape of a mesh plate.

5. The control method according to claim 4, characterized in that, The environmental parameter abnormality in any step S4-S10 is specifically determined as follows: if at least one of the four data of temperature, pH value, dissolved oxygen and redox potential detected by the environmental module (2) is not within the set normal range, it is determined that the environmental parameter is abnormal. If the four environmental parameters detected by the environmental module (2) are all within the set normal range, the environmental parameters are considered normal.

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