Denitrification nitrogen removal integrated constructed wetland sewage treatment device and use method thereof

Abstract

The invention relates to the technical field of sewage treatment, in particular to a denitrification and nitrogen removal integrated constructed wetland sewage treatment device and a use method thereof, the denitrification and nitrogen removal integrated constructed wetland sewage treatment device comprises an artificial pool and a drying well, and further comprises a constructed wetland main body embedded in the artificial pool, the constructed wetland main body is communicated with the artificial pool through a water filling inlet cavity, a water filling outlet cavity and a middle cavity which are formed in the constructed wetland main body, and the constructed wetland main body is provided with an electrode ammoxidation reaction purification assembly which is used for carrying out primary nitrogen removal on sewage to generate nitrate and nitrite through the middle cavity. The artificial pool and the drying well which are matched with each other are arranged, the artificial wetland main body is arranged in the artificial pool, nitrate and nitrite generated by an electrode ammoxidation reaction are reduced through a denitrification reaction, and electromotive force is formed by utilizing the temperature difference between the earth surface and the underground; and meanwhile, the direct current electric energy is stored and managed by utilizing a super capacitor, so that the direct current electric energy is conveniently provided for the electrode ammoxidation purification assembly and the denitrification reaction purification assembly.

Description

Technical Field

[0001] The present invention relates to the technical field of sewage treatment, and particularly to an artificial wetland sewage treatment device integrating denitrification and nitrogen removal and its usage method. Background Art

[0002] Nitrogen in farmland runoff is one of the main causes of water eutrophication. In recent years, many studies usually follow the technical ideas of source control, process blockage, and end treatment to reduce the loss of nitrogen in farmland and reduce its environmental risks. The artificial wetland sewage ecological treatment technology is increasingly applied to the end treatment of farmland runoff. Since farmland runoff is a typical wastewater with a low carbon-nitrogen ratio (C / N), the removal effect of nitrogen in such sewage by most artificial wetland systems is not very ideal, and the low nitrogen removal ability limits the further popularization and application of this technology. The microbial nitrification / denitrification process is generally considered to be the main way for artificial wetlands to remove nitrogen.

[0003] Existing sewage denitrification technologies often adopt a device such as an integrated nitrification and denitrification self-driven microelectric field enhanced artificial wetland disclosed in the patent publication number CN104829065B. When sewage flows down along a slope, the potential energy generated is converted into electric energy, which is connected to the cathode and anode electrodes of the upper and lower layers of the artificial wetland to form a microelectric field. During sewage treatment, the rotation 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 microelectric field can strengthen the nitrification and denitrification processes of the wetland. Another example is a vertical flow artificial wetland sewage treatment system and method for real-time control and management of the nitrification and denitrification nitrogen removal process disclosed in the patent publication number CN111018118B. It is proposed that the vertical flow artificial wetland sewage treatment system can monitor the concentration changes of NH4 + -N, NO3 - -N and the water quality conditions such as DO, pH, and Eh in the vertical flow artificial wetland system in real time, and can make timely adjustments and responses to the reaction situation based on certain evidence when treating sewage with complex and changeable water quality. However, the method of generating electric energy using flowing water is extremely easily restricted by natural conditions, and at the same time, it will also cause problems of difficult regulation of flowing water in the artificial wetland environment, affecting the water content of the artificial wetland and further exacerbating the water pollution problem. Especially in the dry season, it is extremely easy to cause difficulties in electric energy production due to insufficient water sources. Moreover, the alternating current generated by the above method needs to be converted and variably output for utilization, increasing the equipment cost and application difficulty, seriously restricting the progress of the nitrification and denitrification reactions, and only being able to act on NH4 + and NO3 - in the sewage by using a single nitrification-denitrification reaction method. There are many influencing factors affecting the nitrification and denitrification reactions in the artificial wetland environment, and there is a problem of incomplete reaction. Therefore, it is difficult for the nitrification and denitrification reactions to deeply remove ammonia nitrogen in the sewage. Summary of the Invention

[0004] The object 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 integrating denitrification and nitrogen removal and its use method.

[0005] To achieve the above object, the present invention adopts the following technical solutions:

[0006] An artificial wetland sewage treatment device integrating denitrification and nitrogen removal, including an artificial pool and a drying well, further including:

[0007] An artificial wetland main body, which is embedded in the artificial pool, and the artificial wetland main body is connected to the artificial pool through an irrigation water inlet cavity, an irrigation water outlet cavity and a middle cavity opened therein. The artificial wetland main body is provided with an electrode ammonia oxidation reaction purification component for preliminarily removing nitrogen from sewage to generate nitrates and nitrites through the middle cavity, and the artificial wetland main body is provided with a denitrification reaction purification component for cooperating with nitrates and nitrites to perform secondary nitrogen removal on sewage through the irrigation water inlet cavity and the irrigation water outlet cavity;

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

[0009] Preferably, the artificial pool includes:

[0010] A concrete square pool, the top of the concrete square pool is open.

[0011] Preferably, the drying well includes:

[0012] A three-way vertical shaft, the three-way vertical shaft is located on one side of the concrete square pool, and lime powder is distributed outside the three-way vertical shaft.

[0013] Preferably, the artificial wetland main body includes a square box for internally placing an electrode ammonia oxidation reaction purification component and a denitrification reaction purification component. The irrigation water inlet cavity and the irrigation 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.

[0014] Preferably, the electrode ammonia oxidation reaction purification component includes a first oxygen discharge long cavity opened in the square box and communicating with the middle cavity, and an oxygen scavenger is input into the middle cavity through the first oxygen discharge long cavity to form an anaerobic environment. The electrode ammonia oxidation reaction purification component converts ammonia nitrogen in sewage to generate nitrogen, nitrates and nitrites in the anaerobic environment.

[0015] Preferably, the denitrification reaction purification component includes a second oxygen discharge long cavity opened in the square box and communicating with the water injection oral cavity and the water injection outlet cavity, and the water injection oral cavity and the water injection outlet cavity form an anoxic environment by putting fine sand through the second oxygen discharge long cavity. The denitrification reaction purification component converts nitrates and nitrites in sewage to produce nitrogen gas in the anoxic environment.

[0016] Preferably, the Seebeck power supply part 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 underground positions, and the super capacitor is used to collect and release electric energy.

[0017] Preferably, a first discharge antenna corresponding to the denitrification reaction purification component is arranged on the super capacitor, and a second discharge antenna corresponding to the electrode ammonia oxidation reaction purification component is arranged on the super capacitor.

[0018] The usage method of the above artificial wetland sewage treatment device integrating denitrification and nitrogen removal includes the following steps:

[0019] Step S1, the upper connection point and the lower connection point between the first conductor and the second conductor generate electromotive force due to the temperature difference between the surface and underground, and the super capacitor is used to collect electric energy.

[0020] Step S2, the super capacitor supplies power to the electrode ammonia oxidation reaction purification component through the second discharge antenna, so that ammonia nitrogen in the middle cavity is used as an electron donor to produce nitrogen gas, nitrates and nitrites.

[0021] Step S3, the super capacitor supplies power to the denitrification reaction purification component through the first discharge antenna, so that nitrates and nitrites are used as acceptors to produce nitrogen gas.

[0022] Preferably, the electrode ammonia oxidation reaction purification component runs prior to 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 cooperating artificial pool and a drying well. An artificial wetland main body is arranged in the artificial pool, and the Seebeck power supply part is arranged in the drying well under dry conditions. The Seebeck power supply part provides direct current for the artificial wetland main body, so that the artificial wetland can effectively purify the sewage in the artificial pool.

[0025] 2. In the present invention, a square box is installed in an artificial pool as the main body of the constructed wetland. A corresponding middle cavity and side cavities are opened at the middle position of the square box. An electron donor and an electron acceptor are arranged through the middle cavity. The ammonia nitrogen deposited in the sewage is used as the electron donor. A power supply connector electrically connected to the Seebeck power supply unit is arranged between the electron donor and the electron acceptor, so that an anodic ammonia oxidation reaction occurs in the middle cavity, thereby oxidizing ammonia nitrogen into nitrogen or nitrate nitrogen. At the same time, nitrates and nitrites will also be produced due to incomplete oxidation, realizing the preliminary purification of sewage.

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

[0027] 4. In the present invention, a first conductor and a second conductor are coupled by using an upper conductive terminal and a lower conductive terminal. The temperature difference between the ground surface and the underground is used to generate an electromotive force. At the same time, a supercapacitor is used to store and manage the DC electric energy, so as to provide DC electric energy for the anodic ammonia oxidation purification component and the denitrification reaction purification component. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 It is a schematic structural diagram of an integrated constructed wetland sewage treatment device for denitrification and nitrogen removal proposed by the present invention;

[0029] Figure 2 It is a bottom view of an integrated constructed wetland sewage treatment device for denitrification and nitrogen removal proposed by the present invention;

[0030] Figure 3 It is a sectional view of an integrated constructed wetland sewage treatment device for denitrification and nitrogen removal proposed by the present invention;

[0031] Figure 4 It is a schematic structural diagram of the artificial pool and the drying well of an integrated constructed wetland sewage treatment device for denitrification and nitrogen removal proposed by the present invention;

[0032] Figure 5 It is a sectional view of the artificial pool and the drying well of an integrated constructed wetland sewage treatment device for denitrification and nitrogen removal proposed by the present invention;

[0033] Figure 6 It is a schematic structural diagram of the main body of the constructed wetland of an integrated constructed wetland sewage treatment device for denitrification and nitrogen removal proposed by the present invention;

[0034] Figure 7 It is a sectional view of the main body of the constructed wetland of an integrated constructed wetland sewage treatment device for denitrification and nitrogen removal proposed by the present invention;

[0035] Figure 8 Cross-sectional view of the denitrification reaction purification component of the constructed wetland sewage treatment device integrating denitrification and nitrogen removal proposed by the present invention;

[0036] Figure 9 Cross-sectional view of the electrode ammonia oxidation reaction purification component of the constructed wetland sewage treatment device integrating denitrification and nitrogen removal proposed by the present invention;

[0037] Figure 10 Schematic structural diagram of the Seebeck power supply part of the constructed wetland sewage treatment device integrating denitrification and nitrogen removal proposed by the present invention;

[0038] Figure 11 Schematic structural diagram of the power supply connector of the constructed wetland sewage treatment device integrating denitrification and nitrogen removal proposed by the present invention.

[0039] In the figure:

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

[0041] 2. Dry well; 21. Three-way shaft; 22. Well cavity; 23. Port; 24. Communication port;

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

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

[0044] 33. Electrode ammonia oxidation reaction purification component; 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 discharge long cavity;

[0045] 4. Seebeck power supply part; 41. Upper conductive terminal; 42. Lower conductive terminal; 43. First conductor; 44. Second conductor; 45. Super capacitor; 46. Conductive joint; 47. First discharge antenna; 48. Second discharge antenna. Detailed implementation manners

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

[0047] Reference Figures 1 - 11 An artificial wetland sewage treatment device integrating denitrification and nitrogen removal, including an artificial pond 1 and a drying well 2, and also including an artificial wetland main body 3 and a Seebeck power supply unit 4.

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

[0049] The top of the concrete square pond 11 is open. It should be noted that a pond structure with length, width, and depth dimensions of 100m * 100m * 25m is constructed by concrete materials, with an inlet and an outlet reserved. A rain shelter can also be erected above the pond to reduce the influence of external water bodies.

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

[0051] The matrix cavity 13 is opened at the lower end of the concrete square pond 11, and the matrix cavity 13 is used to fill alkaline matrix. The alkaline matrix is preferably limestone and dolomite, which play 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, and then affect the stability of the pH value, so that the pH value of the sewage in the artificial pond 1 and the artificial wetland main body 3 is maintained at 6.5 - 8.5. Because the type and concentration of electrolytes will affect the conductivity, pH value, and existence form of ammonia nitrogen of the solution, and then affect the reaction rate and product distribution, so by controlling the concentration and oxygen content of the sewage in the artificial pond 1, it is helpful for the deep progress of the electrode ammonia oxidation reaction.

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

[0053] The three-way vertical shaft 21 is located on one side of the concrete square pond 11, and lime powder is distributed outside the three-way vertical shaft 21. A square well structure with length, width, and depth dimensions of 2m * 2m * 35m is excavated and reinforced with a concrete structure and waterproof materials. At the same time, under the action of the lime powder, the dryness of the surrounding environmental soil is improved, and the influence of soil humidity on the Seebeck power supply unit 4 is reduced.

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

[0055] The number of ports 23 is two. The two ports 23 are respectively located at the upper and lower ends of the three-way vertical shaft 21 facing the ground and underground. It should be noted that drying structures are correspondingly configured at the upper and lower port 23 positions, and a driving structure for driving the Seebeck power supply unit 4 to deflect horizontally is arranged in one of the ports 23 at the upper position, so that the first conductor 43 and the second conductor 44 can exchange positions and be adjusted and connected to the super capacitor 45.

[0056] There is one connecting port 24 , which is located at the middle end 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 connecting 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 components 33 and denitrification reaction purification components 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 in the artificial pool 1 can be communicated with the water in the water inlet cavity 322 and the water outlet cavity 329. Similarly, the middle cavity 331 can also communicate with the water in the artificial pool 1. The artificial wetland body 3 is provided with an electrode ammonia oxidation reaction purification component 33 for preliminary nitrogen removal 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 charged with a deoxidizer through the first oxygen-discharging long cavity 338 to form an anaerobic environment, and then the oxygen content of the middle cavity 331 is judged by charging an anaerobic indicator, specifically methylene blue. The electrode ammonia oxidation reaction purification component 33 converts ammonia nitrogen in the sewage to produce nitrogen, nitrate and nitrite under 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 edge of the middle end of the square 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 filling 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, and the nitrate and nitrite produced after the electrode ammonia oxidation reaction enter the lower filling cavity 327 through the discharge outlet 334 to provide electron acceptors 336 for the denitrification reaction.

[0062] The electron donor 335 is disposed in the middle cavity 331. The ammonia nitrogen in the constructed wetland main body 3 serves as an anode substrate for anaerobic oxidation to produce energy, and at the same time is used as the electron donor 335. The participating microorganisms are mainly some autotrophic microorganisms with special metabolic abilities, including autotrophic microorganisms such as anaerobic ammonium oxidizing bacteria, which reduce nitrite or nitrate to nitrogen gas, and at the same time oxidize ammonia nitrogen to nitrogen gas or nitrate nitrogen. It should be noted that the electron acceptor 336 is disposed in the middle cavity 331. The current density determines the reaction rate on the electrode surface. Appropriately increasing the current density can accelerate the ammonia oxidation reaction. The current is regulated by the supercapacitor 45. During the anaerobic ammonium oxidation process, nitrite serves as the electron acceptor 336 and reacts with ammonia nitrogen to generate nitrogen gas. During the denitrification reaction process, nitrate can serve as the electron acceptor 336. In wastewater treatment applications, the appropriate electron acceptor 336 and the corresponding reaction system can be selected according to specific process requirements and conditions to achieve efficient ammonia nitrogen removal and water quality 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 a neutral or weakly acidic solution, ammonia mainly exists in the form of NH4 + So the anodic oxidation reaction is:

[0066] NH4 + +NO2 - →N2↑+2H2O

[0067] The overall reaction is:

[0068] 4NH4 + +3O2→2N2+4H + +6H2O

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

[0070] Generating nitrite:

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

[0072] Or

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

[0074] Or add an oxidizing agent (O2)

[0075] 2NH3 + 3O2 → 2NO2 - + 2H + + 2H2O (Neutral condition, oxidizing agent)

[0076] Generate nitrate:[[]]

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

[0078] Or

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

[0080] It should be noted that when using the electrode ammonia oxidation technology to treat wastewater containing high-concentration ammonia nitrogen, by using special electrode materials and optimizing the reaction conditions, including setting an anaerobic environment and an appropriate temperature condition of 20 - 35 °C, and at 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 a good treatment effect and creating favorable conditions for the subsequent biological treatment process.

[0081] The main body 3 of the constructed wetland is provided with a denitrification reaction purification component 32 for secondary nitrogen removal of sewage in cooperation with nitrates and nitrites through the water inlet cavity 322 and the water outlet cavity 329. The denitrification reaction purification component 32 includes a second oxygen discharge long cavity 3210 opened in the square box 31 and communicating with 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 discharge long cavity 3210 to form an anoxic environment. The denitrification reaction purification component 32 converts nitrates and nitrites in the sewage to produce nitrogen in the anoxic environment. The denitrification reaction purification component 32 further includes a planting area 321, an anode electrode end 323, an upper filler cavity 324, a first rotary switch 325, a second rotary switch 326, a lower filler cavity 327, and a cathode electrode end 328:

[0082] The planting area 321 is opened at the top of the square box 31. By planting emergent plants, floating-leaved plants, and submerged plants in the planting area 321, including reeds, cattails, and calamus, which have good tolerance to saline-alkali land and good treatment effects on industrial and mining wastewater, can effectively remove pollutants in water, have a high removal efficiency of TN in combination with reeds, and have good purification effects on pollutants in water bodies. It is preferable to use water club-rush, regenerated flowers, Nuphar pumilum, Potamogeton crispus, and Myriophyllum verticillatum, which can absorb nitrogen and phosphorus nutrients in water and play a role in purifying water bodies.

[0083] The anode electrode end 323 is fixedly inserted through the upper end of the square box 31, and the cathode electrode end 328 is arranged at the lower end of the square box 31. The anode electrode end 323 mainly undergoes oxidation reactions, and ammonia nitrogen may also be oxidized at the anode electrode end 323. The oxidation reaction of the anode electrode end 323 can provide necessary electrons for the denitrification reaction, and at the same time, it also helps to remove some organic pollutants and ammonia nitrogen in the wastewater, reducing the burden of subsequent denitrification treatment. The cathode electrode end 328 is the place where the reduction reaction occurs and is the main area of the denitrification reaction. Electrons are transmitted from the anode electrode end 323 to the cathode electrode end 328 through the external circuit, providing power for the reduction reaction. At the same time, the electric field and catalyst factors on the surface of the cathode electrode end 328 will also affect the rate and product distribution of the denitrification reaction, promoting the progress of the denitrification reaction, increasing the selectivity of nitrogen gas generation, and reducing the accumulation of intermediate products such as nitrite ions or ammonia nitrogen.

[0084] The upper packing chamber 324 is arranged at the upper end of the square box 31, and the upper packing chamber 324 is connected to the aeration pipe 333. The lower packing chamber 327 is arranged at the lower end of the square box 31, and the lower packing chamber 327 is connected to the discharge outlet 334, which is used to provide a surface for microorganisms to attach to, and at the same time promote mass transfer and maintain a stable reaction environment. Specifically, anthracite, ceramsite, activated carbon, zeolite inorganic materials can be used, or synthetic polymer materials such as polypropylene, polyethylene, and polystyrene can be combined. It is preferably made of micro-nano plastic materials, and natural plant fibers and shells can also be selected, which can provide rich nutrients and growth factors for microorganisms. The modified bioactive packing can carry specific microbial strains or enzymes, further improving the efficiency of the denitrification reaction.

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

[0086] Further explanation:

[0087] Using nitrate as the cathode electrode and completely reducing it to nitrogen gas is shown as:

[0088] 2NO3 - +10e - +12H +→N2↑ + 6H2O

[0089] Using nitrate as the cathode electrode, it is reduced to nitric oxide, showing as:

[0090] NO3 - + 3e - + 4H + →NO↑ + 2H2O

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

[0092] NO3 - + 2e - + 2H + →NO2 - + H2O

[0093] Further explanation:

[0094] Using nitrite as the acceptor, it is reduced to nitrogen, showing as:

[0095] 2NO2 - + 6e - + 8H + →N2↑ + 4H2O

[0096] Using nitrite as the acceptor, it is reduced to nitric oxide, showing as:

[0097] NO2 - + e - + 2H + →NO↑ + H2O

[0098] Suitable bacterial enzymes can be selected according to the sewage, including nitrate reductase, nitrite reductase or nitric oxide reductase, nitrous oxide reductase. They act synergistically in the denitrification reaction to gradually reduce the nitrate nitrogen in the wastewater to harmless nitrogen gas, thereby achieving nitrogen removal. At the same time, denitrifying bacteria can adapt to different environmental conditions by regulating the expression and activity of these enzymes to ensure the efficient progress of the denitrification reaction.

[0099] The Seebeck power supply unit 4 is arranged in the dry well 2, and the Seebeck power supply unit 4 is used to provide direct current for the electrode ammonia oxidation reaction purification component 33 and the denitrification reaction purification component in the constructed wetland main 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 underground positions, which can directly generate direct current, avoiding the conversion to direct current due to the alternating current in the external power supply. The supercapacitor 45 is used to collect and release electric energy, and it obtains an extremely large capacity by using the double-layer structure composed of activated carbon porous electrodes and electrolytes. When a voltage is applied across both ends, positive and negative electrons will accumulate on the opposite porous electrodes, and positive and negative ions in the electrolyte solution will gather at the interfaces opposite to the positive and negative plates due to the electric field effect, thus forming a double-layer capacitor, which can collect and store the direct current electric energy generated by the Seebeck effect, and at the same time can discharge 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 joint 46:

[0101] The upper conductive terminal 41 is rotatably sleeved in a port 23 located at the surface position, and the upper conductive terminal 41 is used to fixedly sleeve the upper ends of the first conductor 43 and the second conductor 44.

[0102] The lower conductive terminal 42 is rotatably sleeved in another port 23 located at the underground position, and the lower conductive terminal 42 is used to fixedly sleeve the lower ends of the first conductor 43 and the second conductor 44.

[0103] It should be noted that since it is necessary 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 25 m, that is, the upper conductive terminal 41 is located at the surface position, and the lower conductive terminal 42 is located at a position below 25 m deep, specifically, it can be set at a depth of 25 - 40 m. In order to reduce the influence of groundwater, moisture-proofing is achieved by using a concrete structure and lime powder, so that the specific heat capacity around the drying well 2 is small enough, and at the same time, it can also prevent the upper conductive terminal 41 and the lower conductive terminal 42 from being affected by moisture.

[0104] However, affected by climate and weather, the temperature between the upper conductive terminal 41 and the lower conductive terminal 42 will reverse, that is, there will be a situation where the surface temperature is higher than the underground temperature, and there will also be a situation where the surface temperature is lower than the underground temperature. Therefore, by rotating the upper conductive terminal 41 and the lower conductive terminal 42, the first conductor 43, the second conductor 44 and the conductive joint 46 are alternately contacted.

[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 horizontally interchanged, so that they can be alternately contacted with the conductive joint 46. Specifically, a gear set made of insulating material can be used for transmission drive.

[0106] The conductive joint 46 is fixedly connected to the supercapacitor 45, and the conductive joint 46 corresponds to the first conductor 43 and the second conductor 44. It should be noted that the supercapacitor 45 is slidably installed at the position of the communication port 24, and is arranged to linearly reciprocate the supercapacitor 45 so that the conductive joint 46 can be movably abutted against the first conductor 43 or the second conductor 44.

[0107] A first discharge antenna 47 corresponding to the denitrification reaction purification component 32 is arranged on the supercapacitor 45. The first discharge antenna 47 is connected to the anode electrode end 323 and the cathode electrode end 328 through wires. A second discharge antenna 48 corresponding to the electrode ammonia oxidation reaction purification component 33 is arranged on the supercapacitor 45. The second discharge antenna 48 is connected to the power supply connector 337 through wires.

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

[0109] It should be noted 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 the electron donor 335 and the electron acceptor 336, with ammonia nitrogen anode substrate as the electron donor 335, and then an oxidation reaction is carried out;

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

[0112] Therefore, from the perspective of electron transfer, both are redox reactions, both involving the transfer and transmission of electrons. Only the sources and transmission methods of electrons are different, but ultimately both achieve the purpose of converting nitrogen-containing compounds into harmless substances such as nitrogen gas. In the process of biological nitrogen removal from wastewater, it can be regarded as an electron transfer and conversion process through different paths, jointly promoting the removal of nitrogen.

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

[0114] The functional principle of the present invention can be elaborated through the following operation modes:

[0115] An electromotive force is generated at the upper and lower connection points between the first conductor 43 and the second conductor 44 due to the temperature difference between the ground surface and the underground, and the supercapacitor 45 is used to collect electric energy. Specifically, when the temperature of the upper conductive terminal 41 is higher than that of the lower conductive terminal 42, the conductive joint 46 is contacted with the first conductor 43 to store electric energy. When the temperature of the upper conductive terminal 41 is lower than that of the lower conductive terminal 42, the horizontal deflection of the upper conductive terminal 41 and the lower conductive terminal 42 is controlled, that is, the positions of the first conductor 43 and the second conductor 44 are interchanged, and then the conductive joint 46 is contacted with the second conductor 44 to store electric energy.

[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 is used as the electron donor 335 to generate nitrogen, nitrate and nitrite. Specifically, the power supply connector 337 supplies power to 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, and nitrate and nitrite will also be produced due to incomplete reaction. Among them, nitrogen enters the upper packing cavity 324 through the aeration pipe 333, and 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 are used as receptors to generate nitrogen. Specifically, by controlling the opening of the first rotary switch 325 and the second rotary switch 326, the denitrification reaction is carried out with nitrate and nitrite as receptors, so as to be further reduced to nitrogen.

[0118] The electrode ammonia oxidation reaction purification component 33 operates prior to the denitrification reaction purification component 32. It should be noted that by first performing the electrode ammonia oxidation reaction, the ammonia nitrogen in the sewage in the artificial wetland main body 3 is preliminarily oxidized to generate a certain amount of nitrogen, nitrate and nitrite, and then by performing the denitrification reaction, the nitrate and nitrite are reduced to achieve further nitrogen removal.

[0119] The above is only a preferred specific embodiment of the present invention, but the protection scope of the present invention is not limited thereto. Any person skilled in the art within the technical scope disclosed by the present invention, according to the technical solution and inventive concept of the present invention, makes equivalent substitutions or changes, and should be covered by the protection scope of the present invention.

Claims

1. An artificial wetland sewage treatment device integrating denitrification and nitrogen removal, comprising an artificial pond (1) and a drying well (2), characterized in that, It further includes: An artificial wetland main body (3), which is embedded in the artificial pool (1). The artificial wetland main body (3) is connected to the artificial pool (1) through an irrigation water inlet cavity (322), an irrigation water outlet cavity (329) and a middle cavity (331) opened therein. The artificial wetland main body (3) is provided with an electrode ammonia oxidation reaction purification component (33) for preliminarily denitrifying sewage to generate nitrates and nitrites through the middle cavity (331), and the artificial wetland main body (3) is provided with a denitrification reaction purification component (32) for cooperatively denitrifying sewage with nitrates and nitrites through the irrigation water inlet cavity (322) and the irrigation water outlet cavity (329); A Seebeck power supply unit (4), which is movably arranged in the drying well (2), and the Seebeck power supply unit (4) is used to provide direct current for the electrode ammonia oxidation reaction purification component (33) and the denitrification reaction purification component in the artificial wetland main body (3).

2. The integrated constructed wetland sewage treatment device for denitrification and nitrogen removal according to claim 1, characterized in that, The artificial pool (1) includes: A concrete square pool (11) with an open top.

3. The integrated denitrification and nitrogen removal constructed wetland sewage treatment device according to claim 2, wherein The drying well (2) includes: A tee shaft (21) located on one side of the concrete square pool (11), and lime powder is distributed outside the tee shaft (21).

4. The integrated constructed wetland sewage treatment device for denitrification and nitrogen removal according to claim 3, characterized in that, The artificial wetland main body (3) includes a square box (31) for internally placing the electrode ammonia oxidation reaction purification component (33) and the denitrification reaction purification component (32). The irrigation water inlet cavity (322) and the irrigation 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).

5. The integrated artificial wetland sewage treatment device for denitrification and nitrogen removal according to claim 4, characterized in that, The electrode ammonia oxidation reaction purification component (33) includes a first oxygen discharge long cavity (338) opened in the square box (31) and communicating with the middle cavity (331). The middle cavity (331) forms an anaerobic environment by putting an oxygen scavenger through the first oxygen discharge long cavity (338). The electrode ammonia oxidation reaction purification component (33) converts ammonia nitrogen in sewage to generate nitrogen, nitrates and nitrites in the anaerobic environment.

6. The integrated artificial wetland sewage treatment device for denitrification and nitrogen removal according to claim 5, characterized in that, The denitrification reaction purification component (32) includes a second oxygen discharge long cavity (3210) opened in the square box (31) and communicating with the irrigation water inlet cavity (322) and the irrigation water outlet cavity (329). The irrigation water inlet cavity (322) and the irrigation water outlet cavity (329) form an anoxic environment by putting fine sand through the second oxygen discharge long cavity (3210). The denitrification reaction purification component (32) converts nitrates and nitrites in sewage to generate nitrogen in the anoxic environment.

7. The integrated artificial wetland sewage treatment device for denitrification and nitrogen removal according to claim 6, characterized in that, The Seebeck power supply unit (4) includes a first conductor (43), a second conductor (44) and a super capacitor (45). The first conductor (43) and the second conductor (44) generate an electromotive force through the temperature difference between the surface and underground positions, and the super capacitor (45) is used to collect and release electric energy.

8. The integrated artificial wetland sewage treatment device for denitrification and nitrogen removal according to claim 7, characterized in that, A first discharge antenna (47) corresponding to the denitrification reaction purification component (32) is provided on the supercapacitor (45), and a second discharge antenna (48) corresponding to the electrode ammonia oxidation reaction purification component (33) is provided on the supercapacitor (45).

9. A method for using an integrated constructed wetland sewage treatment device for denitrification and nitrogen removal according to claim 8, characterized in that, The usage method includes the following steps: Step S1, an electromotive force is generated between 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 supercapacitor (45) is used to collect electric energy; Step S2, the supercapacitor (45) supplies power to the electrode ammonia oxidation reaction purification component (33) through the second discharge antenna (48), so that ammonia nitrogen in the middle cavity (331) serves as an electron donor (335) to generate nitrogen, nitrate, and nitrite; Step S3, 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 acceptors to generate nitrogen.

10. The usage method of the integrated artificial wetland sewage treatment device for denitrification and nitrogen removal according to claim 9, characterized in that, The electrode ammonia oxidation reaction purification component (33) operates prior to the denitrification reaction purification component (32).

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