A tail water denitrification device

Abstract

The invention discloses a tailwater denitrification device, which belongs to the technical field of tailwater treatment, and includes a vertical flow artificial wetland and a denitrification reactor. The vertical flow artificial wetland includes a carrying container, which is divided into an upper chamber and a lower chamber by a perforated partition plate. A planting soil layer, an iron-carbon filler layer and a zeolite particle layer are sequentially arranged in the upper chamber, a micro-electrolysis device is buried in the zeolite particle layer, a wetland water inlet and a wetland water outlet are arranged in the upper chamber, and a wetland mud outlet is arranged at the bottom of the lower chamber; the denitrification reactor includes an outer cylinder and an inner cylinder; an outer cylinder water inlet and an outer cylinder mud outlet are arranged on the outer cylinder, an outer cylinder water outlet is arranged between the top of the outer cylinder and the top of the inner cylinder, an inner cylinder water inlet, an inner cylinder water outlet and an inner cylinder mud outlet are arranged on the inner cylinder, and a perforated cover plate is installed at the inner cylinder water inlet. The vertical flow artificial wetland and the denitrification reactor are synergistically treated, which can significantly improve the denitrification effect, and promote the small volume and short purification cycle of the vertical flow artificial wetland and the denitrification reactor.

Description

Technical Field

[0001] The invention relates to the technical field of tail water treatment, in particular to a tail water denitrification device. Background Art

[0002] At present, the tailwater purification equipment on the market mainly uses integrated technologies such as biochemical treatment, multi-stage sand filtration and plant purification for coordinated treatment. It can purify tailwater with high COD (Chemical Oxygen Demand), high TP (total phosphorus) and medium and low concentrations of TN (total nitrogen content is less than 20 mg / L). However, there is no economical and effective technical means for the purification of high concentrations of TN (total nitrogen content is higher than 20 mg / L), especially TN purification dominated by nitrate nitrogen. Among them, the biochemical reactor is the main force for removing nitrate nitrogen in the integrated technology. If you want to improve the overall TN purification capacity of the system, the influent needs to be basically nitrate nitrogen. Vertical flow artificial wetlands also have a nitrogen reduction effect, but if used alone, the efficiency is too low. If you want to improve the TN purification effect, you need to significantly increase the floor area and / or extend the treatment cycle, which is also one of the reasons that seriously hinder and restrict the popularization and application of vertical flow artificial wetlands. Summary of the invention

[0003] The purpose of the present invention is to solve the above-mentioned technical problems and provide a tailwater denitrification device, which adopts a coordinated treatment mode of a vertical flow artificial wetland and a denitrification reactor to form a complex nitrogen metabolism network, wherein the vertical flow artificial wetland is used for the denitrification of ammonia nitrogen, and the denitrification reactor is used for the denitrification of nitrate nitrogen, and the total denitrification amount is significantly improved, which is beneficial to the treatment of tailwater with high concentration of TN. The vertical flow artificial wetland introduces iron-carbon fillers and a micro-electrolysis system to significantly improve the degradation rate of COD and NH3-N, which is beneficial to plant absorption and promotes the small size of the vertical flow artificial wetland and the short purification cycle; and the denitrification reactor adopts the method of wrapping the inner cylinder with an outer cylinder, which can not only ensure the denitrification effect, but also relatively reduce the occupied area, which is conducive to promotion.

[0004] To achieve the above-mentioned purpose, the present invention provides the following scheme: The present invention discloses a tailwater denitrification device, including a vertical flow artificial wetland and a denitrification reactor; the vertical flow artificial wetland includes a carrying container with an open top, the carrying container is divided into an upper chamber and a lower chamber arranged up and down by a perforated partition, the upper chamber is provided with a planting soil layer, an iron-carbon filler layer and a zeolite particle layer from top to bottom, the planting soil layer is used for planting plants, a micro-electrolysis device is buried in the zeolite particle layer, a wetland water inlet and a wetland water outlet connected to the denitrification reactor are provided on the upper chamber, the wetland water inlet is located above the planting soil layer, the wetland water outlet corresponds to the zeolite particle layer, and a wetland mud outlet that can be opened and closed is provided at the bottom of the lower chamber; the denitrification reactor includes a closed outer cylinder and an inner cylinder located in the outer cylinder; the outer cylinder is provided with an outer cylinder water inlet and a wetland outlet that can be opened and closed An outer cylinder mud discharge port that can be opened and closed, the outer cylinder mud discharge port is lower than the wetland water outlet, the outer cylinder water inlet is connected with the wetland water outlet, the outer cylinder water inlet is located between the wetland water outlet and the outer cylinder mud discharge port in height, an annular outer cylinder water outlet is provided between the top of the outer cylinder and the top of the inner cylinder, and the outer cylinder water outlet is between the wetland water inlet and the wetland water outlet in height; the inner cylinder is provided with an inner cylinder water inlet, an inner cylinder water outlet and an inner cylinder mud discharge port that can be opened and closed, the inner cylinder water inlet is located at the top of the inner cylinder, a cover plate with holes is installed at the inner cylinder water inlet, the inner cylinder mud discharge port is located at the bottom of the inner cylinder, the inner cylinder mud discharge port is connected with the outer cylinder mud discharge port through a mud discharge pipe, the inner cylinder water outlet is located between the inner cylinder water inlet and the wetland water outlet in height, and the inner cylinder water outlet extends out of the outer cylinder through a horizontally arranged drainage pipe.

[0005] Preferably, the plant is an emergent plant.

[0006] Preferably, the layer thickness ratio of the iron-carbon filler layer to the zeolite particle layer is 1:1-1:5.

[0007] Preferably, the lower chamber is in the shape of a cone with the tip facing downward, and the wetland mud discharge port is located at the tip of the lower chamber.

[0008] Preferably, the micro-electrolysis device is connected to an external DC power source through the top opening of the carrying container.

[0009] Preferably, a stirrer for stirring the liquid in the inner cylinder is installed on the perforated cover plate.

[0010] Preferably, a sealing cover is provided on the top of the outer cylinder, and a carbon source supply inlet that can be opened and closed is provided on the sealing cover.

[0011] Preferably, the volume ratio of the inner cylinder to the outer cylinder is 1:1-10:1.

[0012] Preferably, the height difference between the wetland water inlet and the outer cylinder water outlet is within 1 m.

[0013] Compared with the prior art, the present invention has achieved the following technical effects:

[0014] The present invention adopts a coordinated treatment mode of vertical flow artificial wetland and denitrification reactor, which can form a complex nitrogen metabolism network, wherein the vertical flow artificial wetland is used for denitrification of ammonia nitrogen, and the denitrification reactor is used for denitrification of nitrate nitrogen, and the total denitrification amount is significantly improved, which is beneficial to the treatment of high-concentration TN. At the same time, the vertical flow artificial wetland introduces iron-carbon fillers and micro-electrolysis systems, which significantly improve the degradation rate of COD and NH3-N, are beneficial to plant absorption, and are beneficial to the vertical flow artificial wetland to reduce the footprint and shorten the purification cycle, and promote the promotion of the application of vertical flow artificial wetlands; and the denitrification reactor adopts the mode of outer cylinder wrapping inner cylinder, on the one hand, the primary denitrification process in the outer cylinder The process can generate heat to provide heat for the denitrification of the inner cylinder, reduce the temperature fluctuation of the denitrification process in the inner cylinder, and ensure the denitrification effect. On the other hand, the high head difference (i.e., liquid level difference) can be used to realize the gravity flow of the liquid in the outer cylinder into the inner cylinder without the need for a submersible pump. The liquid level difference between the vertical flow artificial wetland and the outer cylinder is also used to ensure that the liquid level in the outer cylinder can reach above the top of the inner cylinder, that is, the tail water can flow out from the water outlet of the outer cylinder. Moreover, the internal and external integrated setting of the secondary anaerobic denitrification process, compared with two parallel denitrification reactors, not only has a good denitrification effect, but also the occupied area can be relatively reduced, which is conducive to promotion, and the reaction temperature and anaerobic conditions are guaranteed to improve the anaerobic efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0016] Figure 1 Schematic diagram of the structure of a tail water denitrification device in an embodiment of the present invention;

[0017] Figure 2 It is a schematic cross-sectional view of a denitrification reactor in an embodiment of the present invention.

[0018] Explanation of the reference numerals: 1. Carrying container; 2. Perforated partition; 3. Planting soil layer; 4. Iron-carbon filler layer; 5. Zeolite particle layer; 6. Plants; 7. Micro-electrolysis device; 8. DC power supply; 9. Outer cylinder; 10. Inner cylinder; 11. Mud discharge pipe; 12. Perforated cover plate; 13. Arc-shaped bottom cover; 14. Arc-shaped sealing cover; 15. First gate valve; 16. Second gate valve; 17. Driving motor; 18. Stirring rod; 19. Stirring blades; 20. Drain pipe. DETAILED DESCRIPTION

[0019] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0020] This embodiment provides a tailwater denitrification device, such as Figure 1 to Figure 2As shown, it includes a vertical flow artificial wetland and a denitrification reactor. The vertical flow artificial wetland includes a carrying container 1 with an open top, and a perforated partition 2 is provided inside the carrying container 1. The perforated partition 2 divides the carrying container 1 into an upper chamber and a lower chamber arranged up and down. A planting soil layer 3, an iron-carbon filler layer 4 and a zeolite particle layer 5 are arranged in sequence from top to bottom in the upper chamber, and the planting soil layer 3 is used to plant plants 6. The zeolite particle layer 5 is stacked on the perforated partition 2, and a micro-electrolysis device 7 is buried in the zeolite particle layer. A wetland water inlet and a wetland water outlet are provided on the upper chamber, and the wetland water inlet is located above the planting soil layer 3, and the wetland water outlet corresponds to the zeolite particle layer 5. Preferably, the wetland water outlet corresponds to the bottom of the zeolite particle layer 5, and the wetland water outlet is connected to the denitrification reactor. A wetland mud discharge port is provided at the bottom of the lower chamber, and the wetland mud discharge port can be opened and closed for regular mud discharge. The denitrification reactor includes an outer cylinder 9 and an inner cylinder 10. The outer cylinder 9 is a closed structure, and the inner cylinder 10 is inside the outer cylinder 9. The outer cylinder 9 is provided with an outer cylinder water inlet and an outer cylinder mud outlet. The outer cylinder water inlet is connected to the wetland water outlet, and the outer cylinder water inlet is lower than the wetland water outlet, so that the tail water in the carrying container 1 can flow naturally into the outer cylinder 9. The outer cylinder mud outlet is lower than the outer cylinder water inlet, and the outer cylinder mud outlet can be opened and closed to facilitate regular mud removal and control the thickness of the sludge bed. Since the top of the outer cylinder 9 is higher than the top of the inner cylinder 10, the top of the outer cylinder 9 and the top of the inner cylinder 10 form a circular outer cylinder water outlet. The outer cylinder water outlet is higher than the wetland water outlet, but the outer cylinder water outlet is lower than the wetland water inlet, so that the water level in the carrying container 1 is higher than the water level in the outer cylinder 9, so as to ensure that the water level in the outer cylinder 9 can be higher than the top of the inner cylinder 10, so that the tail water can flow into the inner cylinder 10 from the outer cylinder water outlet. The inner tube 10 is provided with an inner tube water inlet, an inner tube water outlet and an inner tube mud discharge port. The inner tube water inlet is located at the top of the inner tube 10. The tail water flowing out of the outer tube water outlet can flow into the inner tube 10 through the inner tube water inlet. A perforated cover plate 12 is installed at the inner tube water inlet for filtering. The inner tube mud discharge port can be opened and closed. The inner tube mud discharge port is located at the bottom of the inner tube 10. The inner tube mud discharge port is connected to the outer tube mud discharge port through a mud discharge pipe 11. The inner tube mud discharge port and the outer tube mud discharge port can be opened to discharge mud regularly to control the thickness of the sludge bed. The inner tube water outlet extends out of the outer tube 9 through a horizontally arranged drainage pipe 20. The inner tube water outlet is higher than the wetland water outlet, but the inner tube water outlet is lower than the inner tube water inlet to ensure that the tail water treated in the inner tube 10 can be effectively discharged.

[0021] Working principle:

[0022] The tail water is introduced into the carrying container 1 through the wetland water inlet, and the water flows through the planting soil layer 3, the iron-carbon filler layer 4 and the zeolite particle layer 5 in sequence. The plants 6 on the planting soil layer 3 adsorb and remove the suspended matter and pathogens in the tail water, slow down the flow rate of the tail water, promote the sedimentation of the suspended matter, and absorb a large amount of inorganic nitrogen, phosphorus and other nutrients, converting them into organic components such as ATP, DNA, PNA of the plants 6, and preliminarily reducing the nitrogen content. The iron-carbon filler layer 4 oxidizes the bait, antibiotics, ammonia nitrogen, feces and animal carcasses remaining in the tail water to improve the biodegradability of the wastewater. The micro-electrolysis device 7 loaded in the zeolite particle layer 5 can electrolyze the tail water, degrade organic matter and NH3-N in the tail water, further reduce the nitrogen content, and produce CO2 (dioxide The carbon dioxide (carbon dioxide) provides a carbon source and creates an anaerobic environment for the anaerobic reaction of the next denitrification reactor. In addition, it will remove calcium and magnesium ions and sterilize. Finally, the water flows from the wetland outlet and the outer tube inlet into the outer tube 9 for primary denitrification. The outer tube 9 creates anaerobic conditions and cultivates anaerobic bacteria. Therefore, the primary denitrification is anaerobic denitrification. The tail water after primary denitrification will enter the inner tube 10 from the outer tube outlet and the inner tube inlet for secondary denitrification. The inner tube 10 is anoxic, so the secondary denitrification is anoxic denitrification. The tail water after secondary denitrification will be discharged from the denitrification reactor through the inner tube outlet and the drain pipe 20 to remove high nitrate nitrogen in the water to further reduce the nitrogen content. The wetland mud outlet needs to be opened regularly for regular mud discharge. Under the comprehensive treatment of vertical flow artificial wetlands and denitrification reactors, after four-step nitrogen elimination treatment, the TN (total nitrogen) concentration in the tail water can be effectively reduced, especially for tail water with a TN concentration greater than 20 mg / L. The denitrification reactor adopts the method of wrapping the inner cylinder 10 with the outer cylinder 9. On the one hand, the primary denitrification process in the outer cylinder 9 can generate heat, provide heat for the denitrification of the inner cylinder 10, reduce the temperature fluctuation of the denitrification process of the inner cylinder 10, and ensure the denitrification effect. On the other hand, by utilizing the high head difference (i.e., liquid level difference), the liquid in the outer cylinder 9 can flow into the inner cylinder 10 by gravity without the need for a submersible pump. Similarly, by utilizing the liquid level difference between the vertical flow artificial wetland and the outer cylinder 9, it is ensured that the liquid level in the outer cylinder 9 can reach the top of the inner cylinder 10, that is, the tail water can flow out from the outer cylinder outlet. Moreover, the internal and external integrated setting of the secondary anaerobic denitrification process, compared with two parallel denitrification reactors, not only has a good denitrification effect, but also the occupied area can be relatively reduced, which is conducive to promotion, and ensures the reaction temperature and anaerobic conditions, and improves the anaerobic efficiency.

[0023] In one embodiment, if Figure 1 to Figure 2 As shown, plant 6 is an emergent plant. Compared with other plants, emergent plants have more developed root systems, which can not only absorb some pollutants, but also transport oxygen to the water body, increase the activity of the water body, form an environment conducive to the growth of microorganisms, further promote the degradation of pollutants, and maintain the ecological balance and purification function of the wetland.

[0024] In one embodiment, if Figure 1 to Figure 2 As shown, the layer thickness ratio of the iron-carbon filler layer 4 to the zeolite particle layer 5 is 1:1 to 1:5.

[0025] In one embodiment, if Figure 1 to Figure 2 As shown, the lower chamber of the supporting container 1 is in the shape of a cone with the tip facing downward, and the wetland mud outlet is located at the tip of the lower chamber. The cone shape is conducive to the concentrated deposition of sludge at the wetland mud outlet to avoid residue when discharging sludge.

[0026] In one embodiment, if Figure 1 to Figure 2 As shown, a first gate valve 15 is installed at the wetland mud outlet to realize the opening and closing of the wetland mud outlet.

[0027] In one embodiment, if Figure 1 to Figure 2 As shown, the micro-electrolysis device 7 is connected to an external DC power source 8 through the top opening of the supporting container 1 , and the DC power source 8 can provide low-voltage DC power to the micro-electrolysis device 7 .

[0028] In one embodiment, if Figure 1 to Figure 2 As shown, the lower half of the outer cylinder 9 is a cone with the clamp end facing downward, and the outer cylinder mud discharge port is located at the tip of the cone. The inner cylinder mud discharge port is located at the bottom end of the inner cylinder 10, and the inner cylinder mud discharge is provided with a second gate valve 16. The mud discharge pipe 11 is vertically arranged, one end is connected to the inner cylinder mud discharge port, and the other end extends to the outer cylinder mud discharge port. The outer cylinder mud discharge port is hinged with an arc bottom cover 13. The outer cylinder mud discharge port can be opened by turning down the arc bottom cover 13 to discharge mud from the outer cylinder 9, and the inner cylinder 10 can be discharged by opening the second gate valve 16.

[0029] In one embodiment, if Figure 1 to Figure 2 As shown, a stirrer is installed on the perforated cover plate 12, and the stirrer is used to stir the liquid in the inner tube 10 to promote the release of nitrogen and methane in the tail water. The stirrer mainly includes a driving motor 17, a stirring rod 18 and a stirring blade 19. The driving motor 17 is installed on the perforated cover plate 12, and the output shaft of the driving motor 17 is coaxially fixedly connected with the stirring rod 18. The stirring blade 19 is arranged on the stirring rod 18, and the stirring rod 18 extends vertically into the inner tube 10. When the driving motor 17 is started, the stirring rod 18 is driven to rotate, and the stirring blade 19 can stir the liquid in the inner tube 10.

[0030] In one embodiment, if Figure 1 to Figure 2 As shown, a cover that can be opened is provided on the top of the outer cylinder 9. The cover can be an arc-shaped cover 14, which is hinged on the top of the outer cylinder 9. The arc-shaped cover 14 can be opened according to actual needs in the later stage to add carbon source to the tail water.

[0031] In one embodiment, if Figure 1 to Figure 2 As shown, the volume ratio of the outer cylinder 9 and the inner cylinder 10 is 1:1 to 10:1.

[0032] In one embodiment, if Figure 1 to Figure 2 As shown, the height difference between the wetland water inlet and the outer tube water outlet is within 1m.

[0033] It should be noted that the height difference between the wetland water inlet and the outer tube water outlet is not limited to within 1m, and can be above 1m. Because generally speaking, the greater the height difference between the wetland water inlet and the outer tube water outlet, the more conducive it is to ensure the head loss, but the increase in height difference will lead to difficulties in design and production, and the height difference between the wetland water inlet and the outer tube water outlet within 1m is sufficient to ensure the head loss, so setting it within 1m is more conducive to design and production, and of course the most preferred setting is 1m.

[0034] The present invention uses specific examples to illustrate the principles and implementation methods of the present invention. The above examples are only used to help understand the method and core ideas of the present invention. At the same time, for those skilled in the art, according to the ideas of the present invention, there will be changes in the specific implementation methods and application scope. In summary, the content of this specification should not be understood as limiting the present invention.

Claims

1. A tailwater denitrification device, characterized in that: It comprises a vertical flow artificial wetland and a denitrification reactor; the vertical flow artificial wetland comprises a carrying container with an open top, the carrying container is divided into an upper chamber and a lower chamber arranged up and down by a perforated partition, the upper chamber is provided with a planting soil layer, an iron-carbon filler layer and a zeolite particle layer from top to bottom, the planting soil layer is used for planting plants, a micro-electrolysis device is buried in the zeolite particle layer, a wetland water inlet and a wetland water outlet connected to the denitrification reactor are provided on the upper chamber, the wetland inlet The water inlet is located above the planting soil layer, the wetland water outlet corresponds to the zeolite particle layer, and a wetland mud outlet that can be opened and closed is provided at the bottom of the lower chamber; the denitrification reactor comprises a closed outer cylinder and an inner cylinder located inside the outer cylinder; the outer cylinder is provided with an outer cylinder water inlet and an outer cylinder mud outlet that can be opened and closed, the outer cylinder mud outlet is lower than the wetland water outlet, the outer cylinder water inlet is connected to the wetland water outlet, and the outer cylinder water inlet is located at a height between the wetland water outlet and the outer cylinder mud outlet There is an annular outer cylinder water outlet between the top of the outer cylinder and the top of the inner cylinder, and the outer cylinder water outlet is between the wetland water inlet and the wetland water outlet in height, so that the water level in the carrying container is higher than the water level in the outer cylinder, and the water level in the outer cylinder is higher than the top of the inner cylinder; the inner cylinder is provided with an inner cylinder water inlet, an inner cylinder water outlet and an inner cylinder mud discharge port that can be opened and closed, the inner cylinder water inlet is located at the top of the inner cylinder, and a cover plate with holes is installed at the inner cylinder water inlet The inner tube mud discharge port is located at the bottom end of the inner tube, the inner tube mud discharge port is connected with the outer tube mud discharge port through a mud discharge pipe, and the inner tube water outlet is located between the inner tube water inlet and the wetland water outlet in height; the inner tube water outlet extends out of the outer tube through a horizontally arranged drainage pipe; by utilizing the liquid level difference between the carrying container, the outer tube and the inner tube, the water in the carrying container can automatically flow into the outer tube, and the water in the outer tube can automatically flow into the inner tube, without the need for a submersible pump.

2. A tailwater denitrification device according to claim 1, characterized in that: The plant is an emergent plant.

3. A tailwater denitrification device according to claim 1, characterized in that: The layer thickness ratio of the iron-carbon filler layer to the zeolite particle layer is 1:1-1:

5.

4. A tail water denitrification device according to any one of claims 1 to 3, characterized in that: The lower chamber is in the shape of a cone with the tip facing downward, and the wetland mud discharge port is located at the tip of the lower chamber.

5. A tailwater denitrification device according to claim 1, characterized in that: The micro-electrolysis device is connected to an external direct current power source through the top opening of the carrying container.

6. A tailwater denitrification device according to claim 1, characterized in that: The perforated cover plate is provided with an agitator for agitating the liquid in the inner cylinder.

7. The tail water denitrification device according to claim 1, characterized in that: A sealing cover is provided on the top of the outer cylinder, and a carbon source supply inlet that can be opened and closed is provided on the sealing cover.

8. The tail water denitrification device according to claim 1, characterized in that: The volume ratio of the inner cylinder to the outer cylinder is 1:1 to 10:

1.

9. A tailwater denitrification device according to claim 1, characterized in that: The height difference between the wetland water inlet and the outer tube water outlet is within 1 m.

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