Constructed wetland sewage treatment device integrating denitrification and denitrification and its use method

Abstract

The present invention relates to the field of sewage treatment technology, and in particular to an artificial wetland sewage treatment device integrating denitrification and denitrification, and a method for using the device. The device comprises an artificial pond and a drying well, and further comprises: an artificial wetland body embedded in the artificial pond, and the artificial wetland body is connected to the artificial pond via a water inlet cavity, a water outlet cavity, and a middle cavity provided therein, and the artificial wetland body is provided with an electrode ammonia oxidation purification component for performing preliminary nitrogen removal on sewage to generate nitrate and nitrite through the middle cavity. The present invention provides a matching artificial pond and a drying well, and provides the artificial wetland body in the artificial pond. The device reduces the nitrate and nitrite generated by the electrode ammonia oxidation reaction by performing a denitrification reaction, utilizes the temperature difference between the surface and the underground to generate an electromotive force, and utilizes a supercapacitor to store and manage DC power, so as to provide DC power for the electrode ammonia oxidation purification component and the denitrification purification component.

Description

Technical Field

[0001] The present invention relates to the technical field of sewage treatment, and in particular to an artificial wetland sewage treatment device integrating denitrification and denitrification and a method for using the device. Background Art

[0002] Nitrogen in farmland runoff is one of the main causes of eutrophication. In recent years, numerous studies have focused on reducing nitrogen losses from farmland and mitigating environmental risks, often through source control, process interruption, and end-of-pipe treatment. Constructed wetland wastewater ecological treatment technology is increasingly being applied to end-of-pipe treatment of farmland runoff. However, since farmland runoff typically has a low carbon-to-nitrogen ratio (C / N) ratio, most constructed wetland systems are less than ideal for nitrogen removal from this wastewater. This low nitrogen removal capacity limits the further application of this technology. Microbial nitrification / denitrification is generally considered the primary pathway for nitrogen removal in constructed wetlands.

[0003] Existing sewage denitrification technologies often use an integrated nitrification and denitrification self-driven micro-electric field device for strengthening artificial wetlands, such as the one disclosed in announcement number CN104829065B. The device converts the potential energy generated when sewage flows down the slope into electrical energy, and connects it to the negative and positive electrodes in the lower and upper layers of the artificial wetland to form a micro-electric field. During sewage treatment, a rotary switch controls the upper and lower layers of the artificial wetland to carry out nitrification and denitrification reactions, respectively, thereby forming aerobic and anaerobic environments, respectively. The micro-electric field can enhance the nitrification and denitrification process of the wetland. Another example is a vertical flow artificial wetland sewage treatment system and method for real-time control and management of nitrification and denitrification processes disclosed in announcement number CN111018118B, which proposes that the vertical flow artificial wetland sewage treatment system can monitor the NH4 + -N, NO3 - -N concentration changes and water quality conditions such as DO, pH and Eh can be used to make timely adjustments and responses to the reaction conditions when treating sewage with complex and changeable water quality. However, the method of using flowing water to produce electricity makes it very easy to be restricted by natural conditions, and it will also lead to the problem of difficult water flow regulation in the artificial wetland environment, affecting the water content of the artificial wetland and further aggravating the water pollution problem. Especially in the dry season, it is easy to cause difficulties in electricity production due to insufficient water resources. Moreover, the above method generates alternating current, which needs to be converted and output in disguised form before it can be used, which increases the preparation cost and application difficulty, and seriously limits the nitrification and denitrification reaction. Moreover, the use of a single nitrification-denitrification reaction method can only treat NH4 + and NO3 - However, there are many factors that affect the nitrification and denitrification reaction in the artificial wetland environment, and there is a problem of incomplete reaction. Therefore, it is difficult for the nitrification and denitrification reaction to deeply remove ammonia nitrogen in sewage. Summary of the Invention

[0004] The purpose of the present invention is to solve the problem in the prior art that it is difficult to deeply remove nitrogen from sewage, which easily leads to eutrophication of water bodies, and to propose an artificial wetland sewage treatment device that integrates denitrification and denitrification and a method of using the same.

[0005] In order to achieve the above object, the present invention adopts the following technical solutions:

[0006] The artificial wetland sewage treatment device integrating denitrification and denitrification includes an artificial pool and a drying well, as well as:

[0007] An artificial wetland body, wherein the artificial wetland body is embedded in an artificial pond and is connected to the artificial pond via a water inlet cavity, a water outlet cavity, and a middle cavity provided therein. The artificial wetland body is provided with an electrode ammonia oxidation reaction purification component for performing preliminary nitrogen removal on sewage to generate nitrate and nitrite through the middle cavity, and the artificial wetland body is provided with a denitrification reaction purification component for performing secondary nitrogen removal on sewage in combination with nitrate and nitrite through the water inlet cavity and the water outlet cavity;

[0008] A Seebeck power supply unit, which is movably arranged in the dry well and is used to provide direct current to the electrode ammonia oxidation reaction purification component and the denitrification reaction purification component in the artificial wetland body;

[0009] The artificial wetland body includes a square box for built-in electrode ammonia oxidation reaction purification components and denitrification reaction purification components, the water inlet cavity and the water outlet cavity are symmetrically opened at the upper and lower ends of the square box, and the middle cavity is opened at the middle end of the square box;

[0010] The electrode ammonia oxidation reaction purification component includes a first oxygen-discharging long cavity opened in the square box and connected to the middle cavity, and the middle cavity is fed with a deoxidizer through the first oxygen-discharging long cavity to form an anaerobic environment. The electrode ammonia oxidation reaction purification component converts ammonia nitrogen in the sewage to produce nitrogen, nitrate and nitrite in the anaerobic environment;

[0011] The denitrification reaction purification component includes a second oxygen-discharging long cavity opened in the square box and connected to the water inlet cavity and the water outlet cavity, and the water inlet cavity and the water outlet cavity are fed with fine sand through the second oxygen-discharging long cavity to form an anoxic environment. The denitrification reaction purification component converts nitrate and nitrite in the sewage to produce nitrogen gas in the anoxic environment.

[0012] The Seebeck power supply unit includes a first conductor, a second conductor and a super capacitor. The first conductor and the second conductor generate electromotive force through the temperature difference between the surface and the underground position. The super capacitor is used to collect and release electrical energy.

[0013] Preferably, the artificial pond comprises:

[0014] A concrete square pool with an open top.

[0015] Preferably, the drying well comprises:

[0016] A three-way vertical shaft is located on one side of the concrete square pool, and lime powder is distributed on the outside of the three-way vertical shaft.

[0017] Preferably, the supercapacitor is provided with a first discharge antenna corresponding to the denitrification reaction purification component, and the supercapacitor is provided with a second discharge antenna corresponding to the electrode ammonia oxidation reaction purification component.

[0018] The method for using the above-mentioned artificial wetland sewage treatment device integrating denitrification and denitrification comprises the following steps:

[0019] Step S1: an electromotive force is generated at the upper connection point and the lower connection point between the first conductor and the second conductor due to the temperature difference between the surface and the underground, and the electric energy is collected by a supercapacitor;

[0020] Step S2: The supercapacitor supplies power to the electrode ammonia oxidation reaction purification component through the second discharge antenna, so that the ammonia nitrogen in the middle cavity acts as an electron donor to produce nitrogen, nitrate and nitrite;

[0021] In step S3, the supercapacitor supplies power to the denitrification purification component through the first discharge antenna, so that nitrate and nitrite serve as receptors to generate nitrogen.

[0022] Preferably, the electrode ammonia oxidation reaction purification component is operated before the denitrification reaction purification component.

[0023] Compared with the prior art, the present invention has the following advantages:

[0024] 1. The present invention sets up a matching artificial pool and a drying well. The artificial wetland body is set in the artificial pool. The Seebeck power supply unit is set in the drying well under dry conditions. The Seebeck power supply unit is used to provide direct current to the artificial wetland body, so that the artificial wetland can effectively purify the sewage in the artificial pool.

[0025] 2. The present invention embeds a square box in an artificial pond as the main body of the artificial wetland, opens a corresponding middle cavity and side cavity at the middle end of the square box, and arranges an electron donor and an electron acceptor through the middle cavity. Ammonia nitrogen deposited in sewage is used as the electron donor, and a power supply connector electrically connected to the Seebeck power supply part is arranged between the electron donor and the electron acceptor, so that an electrode ammonia oxidation reaction occurs in the middle cavity, thereby oxidizing the ammonia nitrogen into nitrogen gas or nitrate nitrogen. At the same time, nitrate and nitrite are produced due to incomplete oxidation, thereby achieving preliminary purification of the sewage.

[0026] 3. The present invention sequentially arranges a planting area, a water inlet cavity, an upper filling cavity, a lower filling cavity, and a water outlet cavity at the upper and lower ends of the square box. At the same time, an anode electrode terminal and a cathode electrode terminal electrically connected to the Seebeck power supply unit are arranged. Nitrates and nitrites generated by the electrode ammonia oxidation reaction are reduced by a denitrification reaction to further purify and remove nitrogen from the sewage.

[0027] 4. The present invention utilizes the upper conductive terminal and the lower conductive terminal to set up a first conductor and a second conductor coupled, utilizes the temperature difference between the surface and the underground to generate an electromotive force, and utilizes a supercapacitor to store and manage DC power, so as to provide DC power for the electrode ammonia oxidation purification component and the denitrification reaction purification component. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 This is a schematic diagram of the structure of the artificial wetland sewage treatment device integrating denitrification and denitrification proposed in the present invention;

[0029] Figure 2 This is a bottom view of the artificial wetland sewage treatment device integrating denitrification and denitrification proposed by the present invention;

[0030] Figure 3 This is a cross-sectional view of the artificial wetland sewage treatment device integrating denitrification and denitrification proposed by the present invention;

[0031] Figure 4 This is a schematic diagram of the structure of the artificial pool and drying well of the artificial wetland sewage treatment device integrating denitrification and denitrification proposed in the present invention;

[0032] Figure 5 This is a cross-sectional view of the artificial pool and drying well of the artificial wetland sewage treatment device integrating denitrification and denitrification proposed in the present invention;

[0033] Figure 6 This is a schematic diagram of the main structure of the artificial wetland of the artificial wetland sewage treatment device integrating denitrification and denitrification proposed in the present invention;

[0034] Figure 7 This is a cross-sectional view of the artificial wetland main body of the artificial wetland sewage treatment device integrating denitrification and denitrification proposed in the present invention;

[0035] Figure 8 This is a cross-sectional view of the denitrification reaction purification component of the artificial wetland sewage treatment device integrating denitrification and denitrification proposed in the present invention;

[0036] Figure 9 This is a cross-sectional view of the electrode ammonia oxidation reaction purification component of the artificial wetland sewage treatment device integrating denitrification and denitrification proposed in the present invention;

[0037] Figure 10This is a schematic diagram of the Seebeck power supply structure of the artificial wetland sewage treatment device with integrated denitrification and denitrification proposed in the present invention;

[0038] Figure 11 This is a schematic diagram of the power supply connector structure of the artificial wetland sewage treatment device integrating denitrification and denitrification proposed in the present invention.

[0039] In the picture:

[0040] 1. Artificial pool; 11. Concrete square pool; 12. Embedded cavity; 13. Matrix cavity;

[0041] 2. Drying well; 21. Three-way vertical shaft; 22. Well cavity; 23. Port; 24. Connecting port;

[0042] 3. Main body of artificial wetland; 31. Square box;

[0043] 32. Denitrification reaction purification component; 321. Planting area; 322. Water inlet cavity; 323. Anode electrode terminal; 324. Upper filling cavity; 325. First rotary switch; 326. Second rotary switch; 327. Lower filling cavity; 328. Cathode electrode terminal; 329. Water outlet cavity; 3210. Second oxygen exhaust cavity;

[0044] 33. Electrode ammonia oxidation reaction purification assembly; 331. Middle cavity; 332. Side cavity; 333. Aeration pipe; 334. Discharge outlet; 335. Electron donor; 336. Electron acceptor; 337. Power supply connector; 338. First oxygen row long cavity;

[0045] 4. Seebeck power supply unit; 41. Upper conductive terminal; 42. Lower conductive terminal; 43. First conductor; 44. Second conductor; 45. Supercapacitor; 46. Conductive connector; 47. First discharge antenna; 48. Second discharge antenna. DETAILED DESCRIPTION

[0046] The technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all the embodiments.

[0047] Reference Figures 1-11 The artificial wetland sewage treatment device integrating denitrification and denitrification includes an artificial pool 1 and a drying well 2, as well as an artificial wetland body 3 and a Seebeck power supply unit 4.

[0048] The artificial pool 1 includes a concrete square pool 11, an embedded cavity 12, and a matrix cavity 13:

[0049] The top of the concrete square pool 11 is open. It should be noted that the pool structure with a length, width and depth of 100m*100m*25m is constructed by concrete material, in which a water inlet and outlet are reserved. A canopy can also be erected above the pool body to reduce the impact of external water bodies.

[0050] The embedding cavity 12 is opened at the upper end of the concrete square pool 11 , and is used to embed the artificial wetland body 3 . A limiting structure for fixing the artificial wetland body 3 is provided in the embedding cavity 12 .

[0051] The matrix cavity 13 is opened at the lower end of the concrete square pool 11, and the matrix cavity 13 is used to fill the alkaline matrix. The alkaline matrix is ​​preferably limestone or dolomite, which plays a role in neutralizing acidic sewage and increasing the pH value. At the same time, the pore structure and chemical properties of the matrix will also affect the flow and reaction of sewage in the wetland, thereby affecting the stability of the pH value, so that the pH value of the sewage in the artificial pool 1 and the artificial wetland body 3 is maintained at 6.5-8.5. Because the type and concentration of the electrolyte will affect the conductivity, pH value and the existence form of ammonia nitrogen in the solution, thereby affecting the reaction rate and product distribution, so by controlling the concentration and oxygen content of the sewage in the artificial pool 1, it is helpful to deepen the electrode ammonia oxidation reaction.

[0052] The drying well 2 includes a three-way vertical well 21, a well cavity 22, a port 23, and a connecting port 24:

[0053] The three-way vertical shaft 21 is located on one side of the concrete square pool 11, and lime powder is distributed on the outside of the three-way vertical shaft 21. By excavating a square shaft structure with a length, width and depth of 2m*2m*35m and reinforcing it with a concrete structure and waterproof materials, the dryness of the surrounding soil is improved under the action of lime powder, thereby reducing the impact of soil moisture on the Seebeck power supply unit 4.

[0054] The well cavity 22 is opened at the middle end of the three-way vertical shaft 21.

[0055] There are two ports 23, which are located at the upper and lower ends of the three-way vertical shaft 21 facing the surface and underground respectively. It should be noted that drying structures are correspondingly configured at the upper and lower ports 23, and a driving structure for driving the Seebeck power supply part 4 to perform horizontal deflection is provided in one of the ports 23 at the upper position, so that the first conductor 43 and the second conductor 44 can be interchanged and adjusted to be connected with the supercapacitor 45.

[0056] There is only one communication port 24 , which is located in the middle of the three-way vertical shaft 21 corresponding to the embedded cavity 12 . It is worth noting that a sealing structure is provided at the communication port 24 to reduce the impact of sewage in the artificial pool 1 on the drying well 2 .

[0057] The artificial wetland body 3 is embedded in the artificial pond 1. The artificial wetland body 3 includes a square box 31 for built-in electrode ammonia oxidation reaction purification component 33 and denitrification reaction purification component 32. The water inlet cavity 322 and the water outlet cavity 329 are symmetrically opened at the upper and lower ends of the square box 31, and the middle cavity 331 is opened at the middle end of the square box 31.

[0058] The artificial wetland body 3 is connected to the artificial pool 1 through the water inlet cavity 322, the water outlet cavity 329 and the middle cavity 331 provided therein. It should be noted that the water inlet cavity 322 and the water outlet cavity 329 can be connected to the water body in the artificial pool 1. Similarly, the middle cavity 331 can also connect the water body with the artificial pool 1. The artificial wetland body 3 is provided with an electrode ammonia oxidation reaction purification component 33 for preliminary denitrification of sewage to generate nitrate and nitrite through the middle cavity 331. The electrode ammonia oxidation reaction purification component 33 includes a square box 31 provided therein. The first oxygen-discharging long cavity 338 is connected to the middle cavity 331, and the middle cavity 331 is fed with a deoxidizer through the first oxygen-discharging long cavity 338 to form an anaerobic environment. Then, an anaerobic indicator, specifically methylene blue, is fed into the middle cavity 331 to determine the oxygen content. The electrode ammonia oxidation reaction purification component 33 converts ammonia nitrogen in the sewage to produce nitrogen, nitrate, and nitrite in the anaerobic environment. The electrode ammonia oxidation reaction purification component 33 also includes a side cavity 332, an aeration pipe 333, a discharge outlet 334, an electron donor 335, an electron acceptor 336, and a power supply connector 337.

[0059] The side cavity 332 is opened at the side of the middle end of the box 31 , and the side cavity 332 cooperates with the communication port 24 to set the Seebeck power supply part 4 .

[0060] The aeration pipe 333 is connected to the upper end of the middle cavity 331, and the nitrogen generated after the electrode ammonia oxidation reaction enters the upper filler cavity 324 through the aeration pipe 333. Figure 9 It should be noted that the nitrogen generated by the electrode ammonia oxidation reaction in the middle cavity 331 enters the upper filling cavity 324 through the first rotary switch 325 and the aeration pipe 333, and is then discharged through the water inlet cavity 322 and the planting area 321.

[0061] The discharge outlet 334 is connected to the lower end of the middle cavity 331. Nitrates and nitrites produced after the electrode ammonia oxidation reaction enter the lower filler cavity 327 through the discharge outlet 334 to provide electron acceptors for the denitrification reaction.

[0062] Electron donor 335 is disposed within central cavity 331. Ammonia nitrogen in the constructed wetland body 3 serves as an anode substrate for anaerobic oxidation to generate energy, also serving as electron donor 335. The participating microorganisms are primarily autotrophic microorganisms with specialized metabolic capabilities, including anaerobic ammonium-oxidizing bacteria. These autotrophic microorganisms reduce nitrite or nitrate to nitrogen gas and simultaneously oxidize ammonia nitrogen to nitrogen gas or nitrate nitrogen. It should be noted that electron acceptor 336 is disposed within central cavity 331. The current density determines the reaction rate at the electrode surface. Properly increasing the current density can accelerate the ammonia oxidation reaction. The current is regulated by supercapacitor 45. During the anaerobic ammonium oxidation process, nitrite acts as electron acceptor 336, reacting with ammonia nitrogen to produce nitrogen gas. During the denitrification reaction, nitrate can serve as electron acceptor 336. In wastewater treatment applications, a suitable electron acceptor 336 and corresponding reaction system can be selected based on specific process requirements and conditions to achieve efficient ammonia nitrogen removal and water purification.

[0063] The power supply connector 337 is disposed in the side cavity 332 , and the power supply connector 337 is electrically connected to the electron donor 335 and the electron acceptor 336 .

[0064] It should be noted that:

[0065] In neutral or weakly acidic solutions, ammonia is mainly present as NH4 + The anodic oxidation reaction is as follows:

[0066] NH4 + +NO2 - →N2↑+2H2O

[0067] The overall reaction is:

[0068] 4NH4 + +3O2→2N2+4H + +6H2O

[0069] However, due to incomplete reaction, ammonia oxidation may not be complete, and nitrite or nitrate may be generated, which is manifested as:

[0070] Formation of nitrite:

[0071] NH3+2H2O→NO2 - +7H + +6e - (Acidic conditions)

[0072] or

[0073] NH3+7OH - →NO2 - +5H2O+6e -(Alkaline conditions)

[0074] Or supplement oxidant (O2)

[0075] 2NH3+3O2→2NO2 - +2H + +2H2O (neutral conditions, oxidant)

[0076] Formation of nitrates:

[0077] NH3+3H2O→NO3 - +9H + +8e - (Acidic conditions)

[0078] or

[0079] NH3+9OH - →NO3 - +6H2O+8e - (Alkaline conditions)

[0080] It is worth noting that the electrode ammonia oxidation technology is used to treat wastewater containing high concentrations of ammonia nitrogen. By using special electrode materials and optimizing reaction conditions, including setting an anaerobic environment and an adapted temperature condition of 20-35°C, and under a certain current density and electrolyte concentration, the ammonia nitrogen concentration in the wastewater can be reduced from 2500-4200 mg / L to 15-60 mg / L, achieving better treatment effects and creating favorable conditions for subsequent biological treatment processes.

[0081] The artificial wetland body 3 is provided with a denitrification reaction purification component 32 for secondary nitrogen removal of sewage with nitrate and nitrite through the water inlet cavity 322 and the water outlet cavity 329. The denitrification reaction purification component 32 includes a second oxygen removal long cavity 3210 opened in the square box 31 and connected to the water inlet cavity 322 and the water outlet cavity 329. The water inlet cavity 322 and the water outlet cavity 329 are filled with fine sand or microorganisms through the second oxygen removal long cavity 3210 to form an anoxic environment. The denitrification reaction purification component 32 converts nitrate and nitrite in the sewage to produce nitrogen gas in the anoxic environment. The denitrification reaction purification component 32 also includes a planting area 321, an anode electrode end 323, an upper filling cavity 324, a first rotary switch 325, a second rotary switch 326, a lower filling cavity 327, and a cathode electrode end 328:

[0082] The planting area 321 is located at the top of the square box 31. By planting emergent plants, floating-leaf plants, and submerged plants, including reeds, cattails, and calamus, in the planting area 321, the plants have good tolerance to saline-alkali land and have a good effect on treating industrial and mining wastewater. They can effectively remove pollutants in the water. When combined with reeds, they have a high removal efficiency for TN and have a good purification effect on pollutants in the water body. Water plantain, regeneration flower, waterweed, water chestnut, and foxtail algae are preferred. They can absorb nitrogen and phosphorus nutrients in the water and play a role in purifying the water body.

[0083] Anode electrode terminal 323 is fixedly inserted into the upper end of box 31, while cathode electrode terminal 328 is located at the lower end of box 31. Anode electrode terminal 323 primarily undergoes an oxidation reaction, and ammonia nitrogen may also be oxidized there. The oxidation reaction at anode electrode terminal 323 provides the necessary electrons for the denitrification reaction, while also helping to remove some organic pollutants and ammonia nitrogen from the wastewater, reducing the burden of subsequent denitrification treatment. Cathode electrode terminal 328 is the site of the reduction reaction and the primary region of denitrification. Electrons are transmitted from anode electrode terminal 323 to cathode electrode terminal 328 via an external circuit, powering the reduction reaction. Furthermore, the electric field and catalyst factors on the surface of cathode electrode terminal 328 also influence the rate and product distribution of the denitrification reaction, promoting the denitrification reaction, improving the selectivity of nitrogen generation, and reducing the accumulation of intermediate products such as nitrite ions or ammonia nitrogen.

[0084] The upper filling cavity 324 is arranged at the upper end of the square box 31, and the upper filling cavity 324 is connected to the aeration pipe 333. The lower filling cavity 327 is arranged at the lower end of the square box 31, and the lower filling cavity 327 is connected to the discharge outlet 334, which is used to provide a surface for microbial attachment, while promoting material transfer and maintaining a stable reaction environment. Specifically, anthracite, ceramsite, activated carbon, zeolite inorganic materials can be used, and polypropylene, polyethylene, polystyrene synthetic polymer materials can also be used, preferably micro-nano plastic materials, and natural plant fibers and shells can also be used, which can provide rich nutrients and growth factors for microorganisms. The modified bioactive filler can load specific microbial strains or enzymes to further improve the efficiency of the denitrification reaction.

[0085] The first rotary switch 325 is disposed at the upper end of the box 31 , and the second rotary switch 326 is disposed at the lower end of the box 31 .

[0086] Further explanation:

[0087] Using nitrate as cathode electrode, it is completely reduced to nitrogen gas, showing as follows:

[0088] 2NO3 - +10e - +12H +→N2↑+6H2O

[0089] Using nitrate as cathode electrode, it is reduced to nitric oxide, which is shown as follows:

[0090] NO3 - +3e - +4H + →NO↑+2H2O

[0091] Using nitrate as cathode electrode, it is reduced to nitrite, showing as follows:

[0092] NO3 - +2e - +2H + →NO2 - +H2O

[0093] Further explanation:

[0094] Using nitrite as the receptor, it is reduced to nitrogen gas, which manifests as:

[0095] 2NO2 - +6e - +8H + →N2↑+4H2O

[0096] Using nitrite as receptor, it is reduced to nitric oxide, which manifests as:

[0097] NO2 - +e - +2H + →NO↑+H2O

[0098] Appropriate bacterial enzymes can be selected based on the wastewater, including nitrate reductase, nitrite reductase, nitric oxide reductase, and nitrous oxide reductase. These enzymes work synergistically in the denitrification reaction, gradually reducing nitrate nitrogen in the wastewater to harmless nitrogen gas, thereby achieving nitrogen removal. Denitrifying bacteria can also adapt to different environmental conditions by regulating the expression and activity of these enzymes to ensure efficient denitrification.

[0099] The Seebeck power supply unit 4 is movably arranged in the drying well 2 , and is used to provide direct current to the electrode ammonia oxidation reaction purification component 33 and the denitrification reaction purification component in the artificial wetland body 3 .

[0100] The Seebeck power supply unit 4 includes a first conductor 43, a second conductor 44 and a supercapacitor 45. The first conductor 43 and the second conductor 44 generate an electromotive force through the temperature difference between the surface and the underground position, which can directly generate direct current, avoiding the transition method of converting the alternating current in the external power supply into direct current. The supercapacitor 45 is used to collect and release electrical energy. It uses a double-layer structure composed of activated carbon porous electrodes and electrolytes to obtain ultra-large capacity. When voltage is applied to both ends, positive and negative electrons will accumulate on the opposite porous electrodes, and the positive and negative ions in the electrolyte solution will gather on the interface opposite to the positive and negative plates due to the action of the electric field, thereby forming a double collecting layer, which can collect and store the direct current electrical energy generated by the Seebeck effect. At the same time, it can be discharged according to the needs of the electrode ammonia oxidation reaction and denitrification reaction, providing direct current for the electrode ammonia oxidation reaction purification component 33 and the denitrification reaction purification component 32. The Seebeck power supply unit 4 also includes an upper conductive terminal 41, a lower conductive terminal 42, and a conductive connector 46:

[0101] The upper conductive terminal 41 is rotatably mounted in a port 23 located on the ground surface, and is used to securely mount the upper ends of the first conductor 43 and the second conductor 44 .

[0102] The lower conductive terminal 42 is rotatably mounted in the other port 23 located underground, and is used to securely mount the lower ends of the first conductor 43 and the second conductor 44 .

[0103] It is worth noting that in order to ensure a sufficient temperature difference between the upper conductive terminal 41 and the lower conductive terminal 42, the depth of the drying well 2 is greater than 25m, that is, the upper conductive terminal 41 is located on the surface, and the lower conductive terminal 42 is located below a depth of 25m, specifically, it can be set at a depth of 25-40m. In order to reduce the impact of groundwater, moisture-proofing is achieved by adopting concrete structure and lime powder, so that the specific heat capacity around the drying well 2 is sufficiently small, and at the same time, it can also prevent the upper conductive terminal 41 and the lower conductive terminal 42 from getting damp.

[0104] Due to the influence of climate and weather, the temperature between the upper conductive terminal 41 and the lower conductive terminal 42 will reverse, that is, the surface temperature may be higher than the underground temperature, and the surface temperature may be lower than the underground temperature. Therefore, by rotating the upper conductive terminal 41 and the lower conductive terminal 42, the first conductor 43 is alternately in contact with the second conductor 44 and the conductive connector 46.

[0105] It should be noted that by providing a driving structure on the drying well 2 for driving the upper conductive terminal 41 and the lower conductive terminal 42 to rotate horizontally, the first conductor 43 and the second conductor 44 can be interchanged in horizontal position, so that they can be in replaceable contact with the conductive connector 46. Specifically, a gear set made of insulating material can be used for transmission drive.

[0106] The conductive connector 46 is fixedly connected to the supercapacitor 45, and the conductive connector 46 corresponds to the first conductor 43 and the second conductor 44. It is worth noting that the supercapacitor 45 is slidably mounted at the communication port 24, and is configured to pull the supercapacitor 45 to move linearly back and forth so that the conductive connector 46 can be in active contact with the first conductor 43 or the second conductor 44.

[0107] The supercapacitor 45 is provided with a first discharge antenna 47 corresponding to the denitrification reaction purification component 32, and the first discharge antenna 47 is connected to the anode electrode terminal 323 and the cathode electrode terminal 328 through a wire. The supercapacitor 45 is provided with a second discharge antenna 48 corresponding to the electrode ammonia oxidation reaction purification component 33, and the second discharge antenna 48 is connected to the power supply connector 337 through a wire.

[0108] It should be noted that the specific models and specifications of the first rotary switch 325, the second rotary switch 326, and the supercapacitor 45 need to be selected and determined according to the actual specifications of the device. The specific selection calculation method adopts the existing technology in this field, so it is not repeated here.

[0109] It is worth mentioning that:

[0110] In the electrode ammonia oxidation reaction, ammonia nitrogen loses electrons on the electrode surface to undergo an oxidation reaction, and the electrons are transferred through the electrode. Therefore, by setting an electron donor 335 and an electron acceptor 336, the ammonia nitrogen anode substrate is used as the electron donor 335 to further carry out the oxidation reaction;

[0111] In the denitrification reaction, nitrate or nitrite obtains electrons and is reduced. By setting the anode electrode terminal 323 and the cathode electrode terminal 328, electrons are provided by the donor in this part to the relevant enzymes in the denitrifying bacteria, thereby realizing nitrogen reduction.

[0112] Therefore, from the perspective of electron transfer, both are redox reactions, both involve the transfer and transmission of electrons, but the source and transmission method of electrons are different, but ultimately they both achieve the goal of converting nitrogen-containing compounds into harmless nitrogen gas. In the process of biological denitrification of wastewater, they can be regarded as electron transfer and conversion processes of different pathways, which jointly promote the removal of nitrogen.

[0113] By controlling the electrode potential, current density, electrolyte concentration and other parameters through the supercapacitor 45, the oxidation removal of ammonia nitrogen can be achieved. The operation is relatively simple and easy to automate.

[0114] The present invention can be explained through the following operation mode:

[0115] The upper and lower connection points between the first conductor 43 and the second conductor 44 generate an electromotive force due to the temperature difference between the surface and the underground, and the supercapacitor 45 is used to collect electrical energy. Specifically, when the temperature of the upper conductive terminal 41 is higher than that of the lower conductive terminal 42, it contacts the first conductor 43 through the conductive connector 46 to achieve electrical energy storage. When the temperature of the upper conductive terminal 41 is lower than that of the lower conductive terminal 42, the upper conductive terminal 41 and the lower conductive terminal 42 are controlled to deflect horizontally, that is, the first conductor 43 and the second conductor 44 are controlled to exchange positions, and then contact the second conductor 44 through the conductive connector 46 to achieve electrical energy storage.

[0116] The supercapacitor 45 supplies power to the electrode ammonia oxidation reaction purification component 33 through the second discharge antenna 48, so that the ammonia nitrogen in the middle cavity 331 acts as an electron donor 335 to produce nitrogen, nitrate and nitrite. Specifically, the power supply connector 337 energizes the electron donor 335 and the electron acceptor 336, so that the electron donor 335 with ammonia nitrogen as the anode substrate undergoes an oxidation reaction, thereby generating nitrogen. Nitrate and nitrite may also be generated due to incomplete reaction. The nitrogen enters the upper packing cavity 324 through the aeration pipe 333, while the nitrate and nitrite enter the lower packing cavity 327 through the discharge outlet 334.

[0117] The supercapacitor 45 supplies power to the denitrification reaction purification component 32 through the first discharge antenna 47, so that nitrate and nitrite serve as receptors to produce nitrogen gas. Specifically, by controlling the first rotary switch 325 and the second rotary switch 326 to be turned on, a denitrification reaction is carried out with nitrate and nitrite as receptors, thereby further reducing them to nitrogen gas.

[0118] The electrode ammonia oxidation reaction purification component 33 operates before the denitrification reaction purification component 32. It should be noted that the electrode ammonia oxidation reaction is first performed to perform a preliminary oxidation reaction on the ammonia nitrogen in the sewage in the artificial wetland body 3, so that a certain amount of nitrogen, nitrate and nitrite are produced, and then the denitrification reaction is performed to reduce the nitrate and nitrite to achieve further nitrogen removal.

[0119] The above description is only a preferred specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any technician familiar with the technical field, within the technical scope disclosed by the present invention, who makes equivalent replacements or changes based on the technical solution and inventive concept of the present invention, should be covered by the scope of protection of the present invention.

Claims

1. An artificial wetland sewage treatment device integrating denitrification and denitrification, comprising an artificial pool (1) and a drying well (2), characterized in that: Also includes: An artificial wetland body (3), the artificial wetland body (3) is embedded in the artificial pond (1), and the artificial wetland body (3) is connected to the artificial pond (1) through a water inlet cavity (322), a water outlet cavity (329) and a middle cavity (331) provided therein, the artificial wetland body (3) is provided with an electrode ammonia oxidation reaction purification component (33) for performing preliminary nitrogen removal on sewage to generate nitrate and nitrite through the middle cavity (331), and the artificial wetland body (3) is provided with a denitrification reaction purification component (32) for performing secondary nitrogen removal on sewage in combination with nitrate and nitrite through the water inlet cavity (322) and the water outlet cavity (329); A Seebeck power supply unit (4), the Seebeck power supply unit (4) being movably arranged in the drying well (2), and the Seebeck power supply unit (4) being used to provide direct current to the electrode ammonia oxidation reaction purification component (33) and the denitrification reaction purification component in the artificial wetland body (3); The artificial wetland body (3) includes a square box (31) for housing an electrode ammonia oxidation reaction purification component (33) and a denitrification reaction purification component (32); The electrode ammonia oxidation reaction purification component (33) includes a first oxygen-discharging long cavity (338) opened in the square box (31) and connected to the middle cavity (331), and a deoxidizer is introduced into the middle cavity (331) through the first oxygen-discharging long cavity (338) to form an anaerobic environment. The electrode ammonia oxidation reaction purification component (33) converts ammonia nitrogen in the sewage to produce nitrogen gas, nitrate and nitrite under the anaerobic environment; The denitrification reaction purification component (32) includes a second oxygen removal long cavity (3210) opened in the square box (31) and connected to the water inlet cavity (322) and the water outlet cavity (329), and the water inlet cavity (322) and the water outlet cavity (329) are filled with fine sand through the second oxygen removal long cavity (3210) to form an anoxic environment. The denitrification reaction purification component (32) converts nitrate and nitrite in the sewage in the anoxic environment to produce nitrogen gas; The Seebeck power supply unit (4) includes a first conductor (43), a second conductor (44) and a supercapacitor (45). The Seebeck power supply unit (4) also includes an upper conductive terminal (41), a lower conductive terminal (42) and a conductive connector (46). The first conductor (43) and the second conductor (44) generate an electromotive force through the temperature difference between the surface and the underground. The supercapacitor (45) is used to collect and release electrical energy. The conductive connector (46) is fixedly connected to the supercapacitor (45), and the conductive connector (46) corresponds to the first conductor (43) and the second conductor (44). By arranging a driving structure for driving the upper conductive terminal (41) and the lower conductive terminal (42) to rotate horizontally on the drying well (2), the first conductor (43) and the second conductor (44) can be horizontally interchanged and can be in replaceable contact with the conductive connector (46).

2. The artificial wetland sewage treatment device integrating denitrification and denitrification according to claim 1, characterized in that: The artificial pond (1) comprises: A concrete square pool (11), wherein the top of the concrete square pool (11) is open.

3. The artificial wetland sewage treatment device integrating denitrification and denitrification according to claim 2, characterized in that: The drying well (2) comprises: A three-way vertical shaft (21) is located on one side of the concrete square pool (11), and lime powder is distributed outside the three-way vertical shaft (21).

4. The artificial wetland sewage treatment device integrating denitrification and denitrification according to claim 3 is characterized in that: The water inlet cavity (322) and the water outlet cavity (329) are symmetrically arranged at the upper and lower ends of the square box (31), and the middle cavity (331) is arranged at the middle end of the square box (31).

5. The artificial wetland sewage treatment device integrating denitrification and denitrification according to claim 4 is characterized in that: The supercapacitor (45) is provided with a first discharge antenna (47) corresponding to the denitrification reaction purification component (32), and the supercapacitor (45) is provided with a second discharge antenna (48) corresponding to the electrode ammonia oxidation reaction purification component (33).

6. A method for using the artificial wetland sewage treatment device integrating denitrification and denitrification according to claim 5, characterized in that: The method of use comprises the following steps: Step S1, an electromotive force is generated at the upper connection point and the lower connection point between the first conductor (43) and the second conductor (44) due to the temperature difference between the surface and the underground, and the electric energy is collected by using a super capacitor (45); In step S2, the supercapacitor (45) supplies power to the electrode ammonia oxidation reaction purification component (33) through the second discharge antenna (48), so that the ammonia nitrogen in the middle cavity (331) acts as an electron donor (335) to generate nitrogen gas, nitrate, and nitrite; In step S3, the supercapacitor (45) supplies power to the denitrification purification component (32) through the first discharge antenna (47), so that nitrate and nitrite serve as receptors to generate nitrogen gas.

7. The method for using the denitrification and denitrification integrated artificial wetland sewage treatment device according to claim 6, characterized in that: The electrode ammonia oxidation reaction purification component (33) operates before the denitrification reaction purification component (32).

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