Reinforced bioelectrochemical device for denitrification of rural sewage

Abstract

The application relates to a reinforced bioelectrochemical rural sewage denitrification device. The left upper portion of the treatment box body is provided with a water inlet pipe, the right lower portion is provided with a water outlet pipe, a biological anode and a biological cathode are vertically arranged in the treatment box body, the upper ends of the biological anode and the biological cathode are respectively electrically connected with a direct-current power supply, the direct-current power supply is powered by a solar power supply system, the biological anode is located at the left side of the biological cathode, an exhaust pipe is arranged at the top of the treatment box body between the biological cathode and the right inner wall of the treatment box body and is communicated with a gas-liquid separator, the treatment box body is filled with adsorption filler embedded with microorganisms and high-molecular conductive filler. The application has the advantages of simple structure, small land occupation, cheap and easily-obtained electrode material and filler, low construction cost, high treatment efficiency, stable operation, stable equipment maintenance, suitability for rural actual conditions, great reduction of sludge yield, no need to inoculate active sludge into the treatment box body, simple operation, shortened treatment time and reduced operation cost.

Description

Technical Field

[0001] This application relates to the field of water purification technology, and in particular to an enhanced bioelectrochemical denitrification device for rural sewage. Background Technology

[0002] With the rapid economic development of coastal areas, the discharge of rural sewage has been increasing year by year, and rural water problems have become increasingly prominent. Compared with urban sewage, rural sewage is characterized by higher nitrogen content, greater seasonal variation in concentration, and better biodegradability. The continuous increase in nitrogen content in water bodies easily leads to eutrophication, causing oxygen deficiency and the production of toxins, thereby endangering the safety of aquatic organisms. Nitrogen-containing nitrosamines formed during the slow conversion of nitrate nitrogen are potential carcinogens, seriously affecting the quality of life of local residents and the ecological environment. Therefore, the treatment and disposal of high-nitrogen sewage has become an important environmental issue.

[0003] Common nitrogen removal processes include physical, chemical, and biological methods. Physical methods mainly include ion exchange, reverse osmosis, electrodialysis, and adsorption; chemical methods mainly include active metal reduction, catalytic reduction, and electrochemical oxidation-reduction. Biological nitrogen removal is currently the most widely used method, offering advantages such as stable treatment effects and low process costs. However, due to the generally low carbon-to-nitrogen ratio in rural domestic sewage, purely biological processes suffer from unstable treatment effects and low nitrogen and phosphorus removal rates. Furthermore, this method requires the addition of an external carbon source in actual operation, occupies a large area, produces a large amount of sludge, consumes a significant amount of energy, and increases equipment maintenance costs.

[0004] Electrochemical technology can selectively convert nitrate nitrogen into ammonia nitrogen, providing a green and efficient method for treating high-nitrogen wastewater. Combining electrochemical technology with traditional biological treatment processes can overcome these shortcomings, thereby significantly improving the nitrogen removal efficiency of wastewater treatment facilities. Furthermore, this process is convenient in operation and maintenance, produces low sludge, and requires no additional carbon source. In recent years, this combined process has been gradually applied to rural domestic wastewater treatment; however, existing technologies and equipment are not yet effectively adapted to the actual conditions of rural wastewater treatment, facing challenges such as large land area requirements, high power consumption, and high construction costs. Utility Model Content

[0005] To address or partially address the problems existing in related technologies, this application provides an enhanced bioelectrochemical rural wastewater denitrification device. It has a simple structure, small footprint, and relatively inexpensive and readily available electrode materials and packings, resulting in low construction costs, high treatment efficiency, stable operation, and stable equipment maintenance, making it suitable for rural realities.

[0006] This application provides an enhanced bioelectrochemical denitrification device for rural sewage, including a treatment tank 1, a bioanode 4, a biocathode 5, an adsorption packing material embedded with microorganisms 6, a polymer conductive packing material 7, a DC power supply 10, and a solar power supply system 11.

[0007] The treatment chamber 1 has an inlet pipe 2 on the upper left side and an outlet pipe 3 on the lower right side. The bioanode 4 and biocathode 5 are vertically placed inside the treatment chamber 1, and their upper ends are electrically connected to the DC power supply 10. The DC power supply 10 is powered by a solar power supply system 11. The bioanode 4 is located to the left of the biocathode 5. An exhaust pipe 8 is provided on the top of the treatment chamber 1 between the biocathode 5 and the right inner wall of the treatment chamber 1, and it is connected to a gas-liquid separator. The treatment chamber 1 is filled with an adsorption filler 6 with embedded microorganisms and a polymer conductive filler 7.

[0008] Optionally, in some embodiments, the processing box 1 is provided with an inclined flow guide baffle 12, the inclined flow guide baffle 12 having an inclination angle of 10° to 20° with the vertical direction, the inclined flow guide baffle 12 being fixed to the top and bottom of the inner cavity of the processing box 1 respectively, and the inclined flow guide baffles 12 fixed to the top and bottom of the inner cavity of the processing box 1 are arranged at intervals, and the lower end of the inclined flow guide baffle 12 fixed to the bottom of the inner cavity of the processing box 1 is provided with a through hole.

[0009] Optionally, in some embodiments, the outlet pipe 3 is connected to a return pipe, and a return pump 9 is installed on the return pipe and connected to the inlet pipe 2. The return pump 9 is powered by a solar power system 11.

[0010] Optionally, in some embodiments, the inner wall of the processing chamber 1 is coated with a corrosion-resistant polytetrafluoroethylene coating with a thickness of 0.1-0.3 mm.

[0011] Optionally, in some embodiments, the treatment chamber 1 is a cuboid structure, with the bioanode 4 and biocathode 5 arranged in parallel along the long axis of the chamber, with a distance of 30-60 cm between them. The space between the bioanode 4 and the biocathode 5 is filled with a polymer conductive filler 7. The space between the bioanode 4 and the treatment chamber 1, as well as between the biocathode 5 and the treatment chamber 1, is filled with an adsorption filler 6 containing embedded microorganisms and a polymer conductive filler 7 in a 1:1 ratio.

[0012] Optionally, in some embodiments, the conductivity of the polymer conductive filler 7 is 0.1 to 0.5 S / m, the porosity is 50% to 80%, the conductive matrix material of the polymer conductive filler 7 is made of polyaniline, the conductive filling particles include carbon nanotubes, graphene sheets, and conductive carbon black, with a proportion of 5% to 20% of the total mass, and the reinforcing agent is silica microspheres.

[0013] Optionally, in some embodiments, the adsorbent filler 6 containing embedded microorganisms is a polyvinyl alcohol-alginate gel composite material with a particle size of 3-5 mm.

[0014] Optionally, in some embodiments, the bioanode 4 is a carbon brush or graphite felt electrode that has been domesticated by nitrifying microorganisms and whose surface is anodized, and the biocathode 5 is a graphite felt electrode with a thickness of 3-5 mm that has been coated with denitrifying microorganisms and formed with a multilayer nanocatalytic coating by electrochemical deposition, and the area ratio of the anode to the cathode is 1:1.5 to 1:2.

[0015] The technical solution provided in this application may include the following beneficial effects:

[0016] The device of this application has a simple structure, small footprint, and relatively inexpensive and readily available electrode materials and fillers, resulting in low construction costs, high processing efficiency, stable operation, and stable equipment maintenance, making it suitable for rural areas.

[0017] This application sets up a biological cathode / anode in the treatment tank of the device. The biological anode is an acclimation electrode after nitrifying microorganisms have attached a biofilm, and the biological cathode is an acclimation electrode after denitrifying microorganisms have attached a biofilm. This not only greatly reduces sludge production, but also eliminates the need to inoculate activated sludge into the treatment tank. The operation is simple, and the treatment time can be shortened and the operating cost reduced.

[0018] This application does not require external aeration. The pure oxygen produced by the electrolysis of water at the anode can be directly utilized by the nitrifying bacteria attached to the anode plate and the nitrifying microorganisms in the adsorption packing. This avoids the long-distance transport of dissolved oxygen in the water body after external aeration, which is conducive to improving the nitrification reaction rate.

[0019] This application enables simultaneous bio-electrochemical nitrification and denitrification without the addition of an external carbon source, converting ammonia nitrogen in wastewater into harmless nitrogen gas. Nitrification and denitrification are coupled via electron transfer. At the biological anode, ammonia nitrogen is oxidized to nitrite and nitrate nitrogen by nitrifying bacteria, simultaneously providing electrons to the circuit. At the biological cathode, nitrite and nitrate nitrogen are reduced to nitrogen gas using electrons provided by an external circuit under the action of denitrifying bacteria. Biological nitrification and denitrification occur simultaneously in the treatment tank, achieving simultaneous autotrophic denitrification.

[0020] Compared with traditional bioelectrochemical biological treatment devices, the adsorption packing material filled with embedded microorganisms further improves the denitrification effect through its own strong adsorption and the synergistic effect of the metabolism of the embedded microorganisms; at the same time, it also has a good removal effect on COD in water.

[0021] This application utilizes a solar power system to supply power to electrical equipment, making it more environmentally friendly and sustainable.

[0022] It should be understood that the above general description and the following detailed description are exemplary and explanatory only, and do not limit this application. Attached Figure Description

[0023] The above and other objects, features and advantages of this application will become more apparent from the more detailed description of exemplary embodiments thereof in conjunction with the accompanying drawings, wherein the same reference numerals generally represent the same components in the exemplary embodiments thereof.

[0024] Figure 1 This is a schematic diagram of the structure of the enhanced bioelectrochemical rural wastewater denitrification device shown in the embodiments of this application.

[0025] Figure label:

[0026] 1-Processing tank; 2-Inlet pipe; 3-Outlet pipe; 4-Bioanode; 5-Biocathode; 6-Inlaid microbial adsorption packing; 7-High molecular conductive packing; 8-Exhaust pipe; 9-Recirculation pump; 10-DC power supply; 11-Solar power supply system; 12-Inclined guide baffle. Detailed Implementation

[0027] Embodiments of this application will now be described in more detail with reference to the accompanying drawings. While embodiments of this application are shown in the drawings, it should be understood that this application may be implemented in various forms and should not be limited to the embodiments set forth herein. Rather, these embodiments are provided to make this application more thorough and complete, and to fully convey the scope of this application to those skilled in the art.

[0028] It should be understood that although the terms "first," "second," "third," etc., may be used in this application to describe various information, this information should not be limited to these terms. These terms are only used to distinguish information of the same type from one another. For example, without departing from the scope of this application, first information may also be referred to as second information, and similarly, second information may also be referred to as first information. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this application, "multiple" means two or more, unless otherwise explicitly specified.

[0029] In the description of this application, it should be understood that the terms "length", "width", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this application.

[0030] Unless otherwise expressly specified and limited, the terms "installation," "connection," "linking," and "fixing," etc., 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. Those skilled in the art can understand the specific meaning of the above terms in this application according to the specific circumstances.

[0031] To address the aforementioned issues, this application provides an enhanced bioelectrochemical rural wastewater denitrification device. This device features a simple structure, small footprint, and readily available and inexpensive electrode materials and packings, resulting in low construction costs, high treatment efficiency, stable operation, and reliable equipment maintenance, making it suitable for rural conditions.

[0032] The technical solutions of the embodiments of this application are described in detail below with reference to the accompanying drawings.

[0033] See Figure 1 The enhanced bioelectrochemical rural sewage denitrification device includes a treatment tank 1, a bioanode 4, a biocathode 5, an adsorption packing material with embedded microorganisms 6, a polymer conductive packing material 7, a DC power supply 10, and a solar power supply system 11.

[0034] The treatment chamber 1 has an inlet pipe 2 on the upper left side and an outlet pipe 3 on the lower right side. The bioanode 4 and biocathode 5 are vertically placed inside the treatment chamber 1, and their upper ends are electrically connected to the DC power supply 10. The DC power supply 10 is powered by a solar power supply system 11. The bioanode 4 is located to the left of the biocathode 5. An exhaust pipe 8 is provided on the top of the treatment chamber 1 between the biocathode 5 and the right inner wall of the treatment chamber 1, and it is connected to a gas-liquid separator. The treatment chamber 1 is filled with an adsorption filler 6 with embedded microorganisms and a polymer conductive filler 7.

[0035] During operation, filtered wastewater enters the treatment tank 1 through the inlet pipe 2. The ammonia nitrogen in the wastewater is converted into nitrite and nitrate by the nitrifying microorganisms attached to the bioanode 4 and the adsorption packing 6 containing embedded microorganisms, while simultaneously providing electrons to the circuit. The bioanode 4 provides oxygen to the nitrifying microorganisms attached to the bioanode 4 and the adsorption packing 6 containing embedded microorganisms through water electrolysis. Subsequently, the nitrite and nitrate nitrogen in the wastewater are reduced to nitrogen gas without secondary pollution by the denitrifying microorganisms attached to the biocathode 5 and the adsorption packing 6 containing embedded microorganisms, thus achieving denitrification treatment. As the wastewater flows through the treatment tank 1, the generated gas is guided to the gas-liquid separation device through the exhaust pipe 8 for separation and discharge. The treated effluent is discharged outside the device through the effluent pipe 3. At the same time, the adsorption packing 6 containing embedded microorganisms also has a good adsorption and removal effect on nitrogen and COD in the wastewater.

[0036] The device is powered by a combination of solar power system 11 and DC power supply 10 to support the electrochemical reaction of bioanode 4 and biocathode 5. It is also equipped with an intelligent power management system to ensure continuous operation of the equipment day and night or in cloudy or sunny conditions. The inlet pipe 2 and outlet pipe 3 are equipped with filter screens to prevent the adsorption packing 6 and polymer conductive packing 7 embedded microorganisms from falling out.

[0037] The exhaust pipe 8 of the device leads to the top of the processing box 1 and is connected to the gas-liquid separator through a sealed connection. The exhaust pipe 8 is made of corrosion-resistant polytetrafluoroethylene. The gas-liquid separator is equipped with a cyclone separation structure or multi-stage separation chamber for efficient separation of nitrogen and water vapor. The separated nitrogen is discharged to the external environment through the exhaust port 8 to avoid water flow turbulence or bubble disturbance from interfering with the stability of the electrochemical reaction area.

[0038] The solar power system 11 includes photovoltaic modules, energy storage batteries, and an intelligent power management module. The system intelligently adjusts the power supply from both the photovoltaic and energy storage batteries, combining this with an external DC power supply to output a stable voltage of 0.5-2V. The voltage is dynamically adjusted based on the ammonia nitrogen concentration in the wastewater, starting at 0.3V and gradually increasing to the target voltage. When sunlight is abundant, the system relies entirely on solar power. When solar energy is insufficient or the energy storage battery is depleted, it switches to an external DC power supply to ensure continuous operation. The combination of solar power and DC power enables all-weather power supply and includes overvoltage and power failure protection functions.

[0039] In some embodiments, the processing box 1 is provided with an inclined flow guide baffle 12. The inclined flow guide baffle 12 has an inclination angle of 10° to 20° with the vertical direction. The inclined flow guide baffle 12 is fixed to the top and bottom of the inner cavity of the processing box 1, and the inclined flow guide baffles 12 fixed to the top and bottom of the inner cavity of the processing box 1 are arranged at intervals. The lower end of the inclined flow guide baffle 12 fixed to the bottom of the inner cavity of the processing box 1 is provided with a through hole.

[0040] During operation, wastewater is introduced into the treatment tank 1 through the inlet pipe 2 and guided by the inclined flow guide baffle 12 inside the treatment tank 1. It flows in a zigzag pattern through the functional reaction zone between the bioanode 4 and the biocathode 5, extending the contact time between the wastewater and the bioanode 4, biocathode 5 and packing. The lower end of the inclined flow guide baffle 12, which is fixed to the bottom of the inner cavity of the treatment tank 1, has a through hole to prevent the formation of dead zones and ensure uniform water flow distribution.

[0041] In some embodiments, the outlet pipe 3 is connected to a return pipe, and a return pump 9 is installed on the return pipe and connected to the inlet pipe 2. The return pump 9 is powered by a solar power system 11.

[0042] During operation, a portion of the treated effluent is returned to the inlet pipe 2 via the return pump 9. The return ratio is adjusted (1:1 to 1:3) to further extend the contact time between the water and the functional packing material, thereby improving the denitrification efficiency. The return pump 9 is a high-efficiency corrosion-resistant pump made of stainless steel or composite plastic, with a rated flow rate of 5-20 m³ / h and a rated head of 5-15 m. The return ratio is 1:1 to 1:3, which can be controlled by a flow regulating valve. The return pipeline is equipped with a flow meter and a sampling port to monitor the return water flow rate and nitrogen concentration in real time, facilitating optimization and control, and improving the denitrification efficiency.

[0043] In some embodiments, the inner wall of the processing chamber 1 is coated with a corrosion-resistant polytetrafluoroethylene coating with a thickness of 0.1-0.3 mm.

[0044] During operation, the inner wall of the treatment chamber 1 is coated with a corrosion-resistant polytetrafluoroethylene coating with a thickness of 0.1-0.3mm to enhance durability and reduce the adhesion of non-target microorganisms, thus avoiding competitive inhibition of nitrifying and denitrifying microorganisms.

[0045] In some embodiments, the treatment chamber 1 has a cuboid structure, and the bioanode 4 and biocathode 5 are arranged in parallel along the long axis of the chamber with a distance of 30-60 cm between them. The space between the bioanode 4 and the biocathode 5 is filled with a polymer conductive filler 7. The bioanode 4 and the treatment chamber 1, as well as the biocathode 5 and the treatment chamber 1, are filled with an adsorption filler 6 containing embedded microorganisms and a polymer conductive filler 7 in a 1:1 ratio.

[0046] During operation, the distance between the bioanode 4 and the biocathode 5 is 30-60cm, which is used for nitrification and denitrification reactions. Only a polymer conductive filler is filled between them to ensure high efficiency of electron transfer and zoning optimization of microbial reaction.

[0047] In some embodiments, the conductivity of the polymer conductive filler 7 is 0.1 to 0.5 S / m, the porosity is 50% to 80%, the conductive matrix material of the polymer conductive filler 7 is made of polyaniline, the conductive filling particles include carbon nanotubes, graphene sheets, and conductive carbon black, with a proportion of 5% to 20% of the total mass, and the reinforcing agent is silica microspheres.

[0048] During operation, the conductive matrix material of the polymer conductive filler 7 is made of polyaniline, and its conductivity is improved through chemical doping process; the conductive filler particles include carbon nanotubes, graphene sheets, and conductive carbon black, with a proportion of 5%-20% of the total mass; the reinforcing agent is silica microspheres, which are used to increase the mechanical strength and specific surface area of ​​the filler.

[0049] In some embodiments, the adsorbent filler 6 containing embedded microorganisms is a polyvinyl alcohol-alginate gel composite material with a particle size of 3-5 mm.

[0050] During operation, the adsorption filler 6 embedded with microorganisms is a polyvinyl alcohol-alginate gel composite material with a particle size of 3-5 mm. It fixes nitrifying microorganisms (such as Nitrosomonas) and denitrifying microorganisms (such as Denitrifying Bacillus) through physical adsorption and chemical cross-linking. 5%-10% of waterborne polyurethane is added to the carrier to enhance its erosion resistance and long-term stability.

[0051] In some embodiments, the bioanode 4 is a carbon brush or graphite felt electrode that has been domesticated by nitrifying microorganisms and whose surface is anodized, and the biocathode 5 is a graphite felt electrode with a thickness of 3-5 mm that has been coated with denitrifying microorganisms and formed with a multilayer nanocatalytic coating by electrochemical deposition. The area ratio of the anode to the cathode is 1:1.5 to 1:2.

[0052] During operation, the bioanode 4 is a carbon brush or graphite felt electrode that has been domesticated by nitrifying microorganisms, and its surface is anolyzed to enhance conductivity; the biocathode 5 is a graphite felt electrode with a biofilm of denitrifying microorganisms, with a thickness of 3-5 mm, and a multi-layer nano-catalytic coating is formed by electrochemical deposition. The area ratio of the anode to the cathode is 1:1.5 to 1:2 to ensure optimal electron transfer efficiency.

[0053] The device is suitable for treating domestic sewage in coastal rural areas and can effectively handle sewage environments with ammonia nitrogen concentrations of 10-250 mg / L. The ammonia nitrogen concentration in the treated effluent is less than 1 mg / L, and the total nitrogen removal rate reaches over 90%.

[0054] Experiment 1

[0055] Taking the treatment of artificial wastewater containing 250 mg / L of ammonia nitrogen as an example, the start-up and operation process of this utility model is described:

[0056] After filtration, the wastewater enters treatment tank 1. The dissolved oxygen content in treatment tank 1 is greater than 0.2 mg / L, and in this embodiment, it is controlled between 0.2 and 0.8 mg / L. When the dissolved oxygen content in treatment tank 1 is lower than 0.2 mg / L, the dissolved oxygen content is maintained between 0.2 mg / L and 0.8 mg / L by adjusting the working voltage of the biological anode 4. The output voltage of the DC power supply is adjusted to be constant at 0.5V, and the flow rate of the reflux pump 9 is adjusted to 800 mL / d. The changes in ammonia nitrogen, nitrate nitrogen, nitrite nitrogen, and total nitrogen in the effluent are monitored regularly. The water quality after 7 days of treatment is shown in Table 1.

[0057] Table 1. Water quality after treatment in Experiment 1

[0058]

[0059] Experiment 2:

[0060] The setup and treatment of ammonia nitrogen content in the enhanced bioelectrochemical rural sewage denitrification device constructed in this embodiment are basically the same as those in Experiment 1. The difference is that the output voltage of the DC power supply is adjusted to 1V. The water quality after 7 days of treatment is shown in Table 2.

[0061] Table 2 Water quality after treatment in Experiment 2

[0062]

[0063]

[0064] Finally, it should be noted that in this document, relationships such as "first" and "second" are used merely to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "include," "contain," or any other variations are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus.

[0065] The units described as separate components may or may not be physically separate. The components shown as units may or may not be physical units; that is, they may be located in one place or distributed across multiple network units. Some or all of the units can be selected to achieve the purpose of this embodiment according to actual needs.

[0066] The various embodiments of this application have been described above. These descriptions are exemplary and not exhaustive, nor are they limited to the disclosed embodiments. Many modifications and variations will be apparent to those skilled in the art without departing from the scope and spirit of the described embodiments. The terminology used herein is chosen to best explain the principles, practical application, or improvement of the technology in the market, or to enable others skilled in the art to understand the embodiments disclosed herein.

Claims

1. A device for enhanced bioelectrochemical denitrification of rural wastewater, characterized in that: The enhanced bioelectrochemical rural sewage denitrification device includes a treatment tank (1), a biological anode (4), a biological cathode (5), an adsorption packing material with embedded microorganisms (6), a polymer conductive packing material (7), a DC power supply (10), and a solar power supply system (11). The upper left side of the treatment box (1) is provided with an inlet pipe (2) and the lower right side is provided with an outlet pipe (3). The bioanode (4) and biocathode (5) are vertically placed inside the treatment box (1) and their upper ends are electrically connected to the DC power supply (10). The DC power supply (10) is powered by a solar power supply system (11). The bioanode (4) is located to the left of the biocathode (5). The top of the treatment box (1) between the biocathode (5) and the right inner wall of the treatment box (1) is provided with an exhaust pipe (8) and connected to a gas-liquid separator. The treatment box (1) is filled with an adsorption filler (6) with embedded microorganisms and a polymer conductive filler (7).

2. The enhanced bioelectrochemical rural wastewater denitrification device according to claim 1, characterized in that: The processing box (1) is provided with an inclined flow guide baffle (12). The inclined flow guide baffle (12) has an inclination angle of 10° to 20° with the vertical direction. The inclined flow guide baffle (12) is fixed at the top and bottom of the inner cavity of the processing box (1) respectively. The inclined flow guide baffles (12) fixed at the top and bottom of the inner cavity of the processing box (1) are arranged at intervals. The lower end of the inclined flow guide baffle (12) fixed at the bottom of the inner cavity of the processing box (1) is provided with a through hole.

3. The enhanced bioelectrochemical rural wastewater denitrification device according to claim 1 or 2, characterized in that: The outlet pipe (3) is connected to a return pipe, and a return pump (9) is installed on the return pipe and connected to the inlet pipe (2). The return pump (9) is powered by a solar power system (11).

4. The enhanced bioelectrochemical rural wastewater denitrification device according to claim 3, characterized in that: The inner wall of the processing box (1) is coated with a corrosion-resistant polytetrafluoroethylene coating with a thickness of 0.1-0.3 mm.

5. The enhanced bioelectrochemical rural wastewater denitrification device according to claim 1, 2, or 4, characterized in that: The processing box (1) is a cuboid structure. The bioanode (4) and biocathode (5) are arranged in parallel along the long axis of the box, with a distance of 30-60 cm between them.

6. The enhanced bioelectrochemical rural wastewater denitrification device according to claim 5, characterized in that: The adsorption filler (6) containing embedded microorganisms is a polyvinyl alcohol-alginate gel composite material with a particle size of 3-5 mm.

7. The enhanced bioelectrochemical rural wastewater denitrification device according to claim 1, 2, 4 or 6, characterized in that: The bioanode (4) is a carbon brush or graphite felt electrode that has been domesticated by nitrifying microorganisms and whose surface is anolyzed. The biocathode (5) is a graphite felt electrode with a biofilm formed by denitrifying microorganisms and a thickness of 3-5 mm. A multilayer nanocatalytic coating is formed by electrochemical deposition. The area ratio of the anode to the cathode is 1:1.5 to 1:2.

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