Anti-blocking deep nitrogen removal device for constructed wetland

Abstract

The utility model relates to the technical field of constructed wetlands, and discloses an anti-blocking deep nitrogen removal device for a constructed wetland. The device comprises a pretreatment area and a functional area which are communicated with each other, the pretreatment area is filled with nitrification filler, and an aerobic nitrification biological membrane is attached to the nitrification filler; a sulfur-free barrier filler layer, a sulfur autotrophic denitrification filler layer and a sulfate radical removal filler layer are sequentially arranged in the functional area from top to bottom, and a sulfur autotrophic denitrification biological membrane is attached to the interior of the sulfur autotrophic denitrification filler layer; a denitrification plant area is arranged above the pretreatment area and the functional area. According to the device disclosed by the utility model, sulfur autotrophic denitrification can be prevented from being inhibited by overhigh dissolved oxygen content in sewage, and sulfur and sulfate radicals in the sulfur autotrophic denitrification filler layer can be prevented from inhibiting growth of denitrifying plants, so that the whole device can realize a relatively good nitrogen removal effect.

Description

Technical Field

[0001] The utility model relates to the technical field of artificial wetlands, in particular to an anti-clogging deep nitrogen removal device for artificial wetlands. Background Art

[0002] Artificial wetlands are artificially constructed and controlled systems that simulate the working principle of natural wetlands. They are often composed of three parts: wetland matrix, wetland plants and wetland microorganisms. Through the synergistic effects of physics, chemistry and biology, pollutants are removed to achieve the purpose of purifying water. Artificial wetland sewage treatment technology has been widely used in various types of sewage treatment due to its advantages such as low construction and operation costs, simple operation, large buffer capacity and eco-friendliness. It can be used for nitrogen and phosphorus removal, heavy metal detoxification, and removal of difficult-to-degrade organic pollutants such as antibiotics.

[0003] Heterotrophic denitrification is the main way to remove nitrates in traditional artificial wetlands, among which the carbon source of the energy donor required for biological denitrification is the main limiting factor. Studies have shown that relying solely on the carbon source of wetland plant root secretions is not enough to achieve deep nitrogen removal. Heterotrophic denitrification requires sufficient carbon sources as electron donors, but it is difficult to accurately add carbon sources. Excessive addition of organic carbon will lead to higher COD in treated sewage and higher costs. It will also weaken hydraulic conductivity and produce a large amount of sludge. In addition, extracellular polymers produced by microorganisms will also cause wetland blockage.

[0004] Sulfur autotrophic denitrification is an alternative technology to improve the efficiency of nitrate-nitrogen removal in artificial wetlands. It can avoid the increase in biological sludge production due to the addition of too much carbon source and reduce the generation of extracellular polymers, which is helpful to prevent clogging. In recent years, sulfur autotrophic denitrification technology has been used in artificial wetlands, but there is still a problem of limited sewage treatment effect. For example, patent CN202310185981.0 discloses an artificial wetland system and method for treating nitrate-nitrogen sewage. The system uses sulfur autotrophic denitrification reaction to remove nitrate-nitrogen from sewage without the need for an external carbon source, but it has the following problems: The nitrogen removal efficiency of sulfur autotrophic denitrification is negatively correlated with the dissolved oxygen content, and the dissolved oxygen content in the sewage is relatively high, which will inhibit the sulfur autotrophic denitrification and result in limited nitrogen removal effect. Utility Model Content

[0005] In order to solve the technical problem of limited nitrogen removal effect of artificial wetland sewage based on sulfur autotrophic denitrification, the utility model provides an artificial wetland anti-clogging deep nitrogen removal device. The device can prevent excessive dissolved oxygen content in sewage from inhibiting sulfur autotrophic denitrification, and prevent sulfur and sulfate in the sulfur autotrophic denitrification filler layer from inhibiting the growth of denitrifying plants, so that the entire device can achieve a better nitrogen removal effect.

[0006] The specific technical solution of the utility model is:

[0007] An anti-clogging deep nitrogen removal device for artificial wetlands comprises a pretreatment area and a functional area which are interconnected; the pretreatment area is filled with a nitrification filler, and an aerobic nitrification biofilm is attached to the nitrification filler; the functional area is provided with a sulfur-free barrier filler layer, a sulfur autotrophic denitrification filler layer and a sulfate radical removal filler layer from top to bottom, and a sulfur autotrophic denitrification biofilm is attached to the sulfur autotrophic denitrification filler layer; a denitrification plant area is provided above the pretreatment area and the functional area.

[0008] During operation of the device of the utility model, sewage first enters the pretreatment area, and under the action of aerobic nitrification biofilm, the dissolved oxygen in the sewage is used for the aerobic nitrification process of microorganisms, thereby effectively reducing the dissolved oxygen content and removing ammonia nitrogen in the sewage; after the effluent from the treatment area enters the functional area, sulfur autotrophic denitrification occurs under the action of sulfur autotrophic denitrification biofilm, and nitrate is reduced to nitrogen gas; the root system of the denitrifying plants can play a denitrification role, and at the same time, the carbon source from the root secretions can also provide a carbon source for the microorganisms in the pretreatment area, thereby improving the efficiency of aerobic nitrification.

[0009] Since the sulfur autotrophic denitrification nitrogen removal efficiency is negatively correlated with the dissolved oxygen content, the sulfur autotrophic denitrification nitrogen removal efficiency in the functional area can be improved by passing the sewage through the pretreatment area and then into the functional area. In addition, the utility model sets the aerobic nitrification and sulfur autotrophic denitrification processes in different areas (pretreatment area and functional area), which can avoid the sulfur autotrophic denitrification process from inhibiting the aerobic nitrification process, thereby improving the nitrogen removal effect.

[0010] In the functional area, the sulfur autotrophic denitrification filler can provide sulfur for microorganisms, but at the same time, sulfur will also have a negative impact on the growth of denitrification plants, and the sulfate generated during the sulfur autotrophic denitrification process will also inhibit the growth of denitrification plants. For this reason, the utility model sets a sulfur-free barrier filler layer between the denitrification plant area and the sulfur autotrophic denitrification filler layer, which can prevent the plant roots from directly contacting the sulfur and sulfate in the sulfur autotrophic denitrification filler layer, thereby ensuring that the denitrification plants can grow and function well. In addition, the utility model sets a sulfate removal filler layer below the sulfur autotrophic denitrification filler layer, which can play a supporting role and remove the sulfate generated by sulfur autotrophic denitrification, thereby avoiding excessive sulfate content in the treated sewage.

[0011] To sum up, the device of the utility model is mainly based on aerobic nitrification, sulfur autotrophic denitrification, the role of denitrification plants and the adsorption effect of fillers. It does not require an external carbon source and can avoid blockage caused by excessive addition of carbon source. On this basis, the utility model adopts a coordinated design of a pretreatment area, a functional area and a denitrification plant area, and arranges a sulfur-free barrier filler layer, a sulfur autotrophic denitrification filler layer and a sulfate removal filler layer in the functional area, which can improve the nitrogen removal effect of the entire device and avoid the introduction of excessive sulfate.

[0012] Preferably, the artificial wetland anti-clogging deep nitrogen removal device also includes a flushing pipe and a sewage pipe; the flushing pipe is arranged at the top of the pretreatment area and the functional area, and is located below the denitrification plant area; the sewage pipe is arranged at the bottom of the pretreatment area and the functional area; a plurality of water distribution outlets are arranged below the flushing pipe; and a plurality of sewage outlets are arranged above the sewage pipe.

[0013] Through the flushing pipe and the drain pipe, the fillers in the pretreatment area and the functional area can be flushed to remove the blockages in the gaps of the fillers to avoid blockage of the device. The specific process is as follows: After the water flows out from the water distribution holes on the flushing pipe, it flows downward from the top of the treatment area and the functional area. In the process, it can take away the blockages in the gaps of the fillers. After reaching the bottom of the pretreatment area and the functional area, it is collected and discharged through the drain pipe.

[0014] Preferably, the diameters of the water distribution outlet and the sewage outlet are no greater than 5 mm.

[0015] Preferably, the artificial wetland anti-clogging deep nitrogen removal device also includes a water pump for pumping the outlet water of the functional area to the flushing pipe; the water pump is connected to the flushing pipe through the flushing water inlet pipe; and a first valve is provided on the flushing water inlet pipe.

[0016] Using the effluent from the functional area to backwash the fillers in the pretreatment area and the functional area can reduce the waste of water resources and lower the operating cost of the device.

[0017] Preferably, a second valve is provided on the sewage pipe.

[0018] Preferably, the artificial wetland anti-clogging deep nitrogen removal device also includes a water inlet area and a water outlet area; the water inlet area is interconnected with the pretreatment area; and the water outlet area is interconnected with the functional area.

[0019] Preferably, the water inlet area and the pretreatment area, the pretreatment area and the functional area, and the functional area and the water outlet area are separated by a first partition, a second partition, and a third partition, respectively.

[0020] Preferably, the lower end of the first partition is provided with a first water outlet connecting the water inlet area and the pretreatment area; the upper end of the second partition is provided with a second water outlet connecting the pretreatment area and the functional area; the lower end of the third partition is provided with a third water outlet connecting the functional area and the water outlet area.

[0021] The first water outlet, the second water outlet and the third water outlet are designed in the above positions, which can extend the flow path of sewage in the pretreatment area and the functional area, so that the pollutants are in more sufficient contact with the filler, thereby improving the nitrogen removal effect of the device. In addition, in the functional area, the sewage flows from top to bottom, which is conducive to preventing the sulfur and sulfate in the sulfur autotrophic denitrification filler layer from flowing upward with the water flow and then contacting the root system of the denitrification plant. At the same time, the sewage after sulfur autotrophic denitrification must pass through the sulfate removal filler layer before being discharged, which is conducive to fully removing the sulfate generated by sulfur autotrophic denitrification.

[0022] Preferably, the top of the third water outlet is not higher than the top of the sulfate removal filler layer.

[0023] The above design helps to prevent the sewage treated by the sulfur autotrophic denitrification packing layer from flowing out of the third outlet without passing through the sulfate removal packing layer, thereby helping to reduce the sulfate content in the effluent of the device.

[0024] Preferably, the first water outlet, the second water outlet and the third water outlet are all formed by porous partitions.

[0025] The use of porous partitions can prevent large particles of pollutants from entering the filler gaps in the pretreatment area and the functional area to cause device clogging. At the same time, it can also avoid the loss of fillers in the pretreatment area and the functional area.

[0026] Furthermore, the porous partition is in a zigzag shape; in the porous partition at the second water outlet, the aperture of the through hole at the upper end is larger than that at the lower end; in the porous partition at the third water outlet, the aperture of the through hole at the upper end is smaller than that at the lower end.

[0027] In a porous partition, the through holes are easily blocked by fillers, causing obstruction of sewage flow. To solve this problem, the utility model adopts a zigzag porous partition, which can reduce the contact between the fillers and the through holes to a certain extent, thereby reducing the blockage of the through holes; and the zigzag porous partition can also increase the surface area of ​​the porous partition without increasing the width of each water outlet to ensure that the sewage fully contacts the fillers before flowing out from the water outlet, thereby promoting the flow of water through the porous partition.

[0028] In addition, by designing the aperture in the porous partition at the second water outlet to be larger at the top and smaller at the bottom, and designing the aperture in the porous partition at the third water outlet to be smaller at the top and larger at the bottom, it is beneficial for the sewage to fully contact the fillers in the pretreatment area and the functional area before flowing out, thereby improving the nitrogen removal effect.

[0029] Furthermore, the pore size of the porous partition is not greater than 3 mm.

[0030] Preferably, a water inlet is provided in the water inlet area; and a fourth water outlet is provided in the water outlet area.

[0031] Preferably, the water pump is arranged in the water outlet area.

[0032] Preferably, the sulfur autotrophic denitrification filler layer is filled with limestone fillers, and sulfur fillers are dispersed between the limestone fillers; or, the sulfur autotrophic denitrification filler layer includes a sulfur filler layer and a limestone filler layer arranged above the sulfur filler.

[0033] Sulfur filler can provide microorganisms with the sulfur required for sulfur autotrophic denitrification, and limestone filler can adjust the pH to prevent the wastewater from being too acidic, providing a suitable pH environment for the growth and metabolism of microorganisms in the sulfur autotrophic denitrification biofilm, thereby improving the efficiency of sulfur autotrophic denitrification.

[0034] Furthermore, the particle size of the limestone filler is 20-30 mm, and the particle size of the sulfur filler is 5-8 mm.

[0035] Preferably, the sulfate-removing filler layer is filled with ashlar and is attached with a sulfate-reducing microbial film.

[0036] The main component of ashlar is CaCO3, which is much harder than limestone and is suitable for support. It can remove sulfate by ion exchange. In addition, the sulfate-reducing bacteria (sulfate-reducing microbial film) coated in the sulfate-removing filler layer can also play a role in removing sulfate.

[0037] Preferably, the nitrating filler is a zeolite filler.

[0038] Preferably, the sulfur-free barrier filler layer is filled with zeolite filler.

[0039] Furthermore, the particle size of the zeolite filler is 5-8 mm.

[0040] Furthermore, the particle size of the ashlar is 20-30 mm.

[0041] Compared with the prior art, the utility model has the following advantages:

[0042] (1) The device of the utility model adopts a coordinated design of a pretreatment area, a functional area and a denitrification plant area, as well as a coordinated design of a sulfur-free barrier filler layer, a sulfur autotrophic denitrification filler layer and a sulfate removal filler layer in the functional area. This can prevent excessive dissolved oxygen content in sewage from inhibiting sulfur autotrophic denitrification, and prevent sulfur and sulfate in the sulfur autotrophic denitrification filler layer from inhibiting the growth of denitrification plants, thereby improving the nitrogen removal effect of the entire device. In addition, it can also prevent the treated sewage from containing too much sulfate.

[0043] (2) The device of the utility model mainly removes nitrogen from sewage based on aerobic nitrification, sulfur autotrophic denitrification, the action of denitrifying plants and the adsorption of fillers. No external carbon source is required, which can avoid clogging of the device due to excessive addition of carbon source.

[0044] (3) In the device of the utility model, by arranging flushing pipes and sewage pipes at specific positions, blockages in the gaps of fillers in the pretreatment area and the functional area can be removed, thereby avoiding blockage of the device. BRIEF DESCRIPTION OF THE DRAWINGS

[0045] Figure 1 It is a schematic diagram of the three-dimensional structure of the artificial wetland anti-clogging deep nitrogen removal device of Example 1.

[0046] Figure 2 It is a schematic diagram of the planar structure of the artificial wetland anti-clogging deep nitrogen removal device of Example 1.

[0047] Figure 3 It is a schematic diagram of the planar structure of the artificial wetland anti-clogging deep nitrogen removal device of Example 2.

[0048] Figure 4 It is a schematic diagram of the planar structure of the artificial wetland anti-clogging deep nitrogen removal device of Example 3.

[0049] The figures are marked as follows: water inlet area 1; pretreatment area 2; functional area 3; water outlet area 4; water inlet 5; first water outlet 6; nitrification filler 7; second water outlet 8; sulfur-free barrier filler layer 9; sulfur autotrophic denitrification filler layer 10; sulfate removal filler layer 11; third water outlet 12; fourth water outlet 13; denitrification plant 14; flushing pipe 15; first valve 16; water pump 17; sewage pipe 18; second valve 19; soil layer 20; first partition 21; second partition 22; third partition 23; flushing water inlet pipe 24; sulfur filler layer 25; limestone filler layer 26. DETAILED DESCRIPTION

[0050] The utility model is further described below in conjunction with embodiments.

[0051] Overall embodiment

[0052] An anti-clogging deep nitrogen removal device for artificial wetlands comprises a pretreatment zone 2 and a functional zone 3 which are interconnected; the pretreatment zone 2 is filled with a nitrification filler 7, and an aerobic nitrification biofilm is attached to the nitrification filler 7; the functional zone 3 is provided with a sulfur-free barrier filler layer 9, a sulfur autotrophic denitrification filler layer 10 and a sulfate radical removal filler layer 11 from top to bottom, and a sulfur autotrophic denitrification biofilm is attached to the sulfur autotrophic denitrification filler layer 10; a denitrification plant zone is provided above the pretreatment zone 2 and the functional zone 3.

[0053] As a specific implementation, the sulfur autotrophic denitrification filler layer 10 is filled with limestone fillers with a particle size of 20-30 mm, and sulfur fillers with a particle size of 5-8 mm are dispersed between the limestone fillers.

[0054] As another specific implementation, the sulfur autotrophic denitrification filler layer 10 includes a sulfur filler layer 25 and a limestone filler layer 26 disposed above the sulfur filler.

[0055] As a specific implementation, the nitrifying filler 7 is a zeolite filler with a particle size of 5 to 8 mm; the sulfur-free barrier filler layer 9 is filled with a zeolite filler with a particle size of 5 to 8 mm; the sulfate removal filler layer 11 is filled with square stone with a particle size of 20 to 30 mm and is attached with a sulfate-reducing microbial film.

[0056] As a specific implementation, the artificial wetland anti-clogging deep nitrogen removal device also includes an inlet area 1 and an outlet area 4; the inlet area 1 is interconnected with the pretreatment area 2; and the outlet area 4 is interconnected with the functional area 3.

[0057] As a specific implementation manner, the water inlet area 1 and the pretreatment area 2, the pretreatment area 2 and the functional area 3, and the functional area 3 and the water outlet area 4 are separated by a first partition 21, a second partition 22, and a third partition 23 respectively; the lower end of the first partition 21 is provided with a first water outlet 6 connecting the water inlet area 1 and the pretreatment area 2; the upper end of the second partition 22 is provided with a second water outlet 8 connecting the pretreatment area 2 and the functional area 3; the lower end of the third partition 23 is provided with a third water outlet 12 connecting the functional area 3 and the water outlet area 4; the first water outlet 6, the second water outlet 8 and the third water outlet 12 are all composed of porous partitions; a water inlet 5 is provided in the water inlet area 1; a fourth water outlet 13 is provided in the water outlet area 4; the top of the third water outlet 12 is not higher than the top of the sulfate removal filler layer 11.

[0058] As a specific embodiment, the porous partition is in a zigzag shape; in the porous partition at the second water outlet 8, the aperture of the through hole at the upper end is larger than the aperture of the through hole at the lower end; in the porous partition at the third water outlet 12, the aperture of the through hole at the upper end is smaller than the aperture of the through hole at the lower end.

[0059] As a specific implementation method, the artificial wetland anti-clogging deep nitrogen removal device also includes a flushing pipe 15 and a sewage pipe 18; the flushing pipe 15 is arranged at the top of the pretreatment area 2 and the functional area 3, and is located below the denitrification plant area; the sewage pipe 18 is arranged at the bottom of the pretreatment area 2 and the functional area 3; a plurality of water distribution outlets are arranged below the flushing pipe 15; and a plurality of sewage outlets are arranged above the sewage pipe 18.

[0060] As a specific implementation, a water pump 17 is provided in the water outlet area 4; the water pump 17 is connected to the flushing pipe 15 through a flushing water inlet pipe 24; a first valve 16 is provided on the flushing water inlet pipe 24; and a second valve 19 is provided on the sewage pipe 18. Specific embodiments

[0062] The present invention is described below by specific examples. These examples are only used to illustrate the present invention and are not used to limit the scope of the present invention. Without departing from the spirit and scope of the inventive concept, changes and advantages that can be thought of by those skilled in the art are included in the present invention, and the attached claims and any equivalents thereof are the protection scope of the present invention.

[0063] It should be understood that in the following specific embodiments, the terms "left", "right", etc. indicate directions or positional relationships based on the directions or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present technical solution and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific direction, be constructed and operated in a specific direction, and therefore cannot be understood as a limitation on the present technical solution.

[0064] Example 1

[0065] A constructed wetland anti-clogging deep nitrogen removal device, such as Figure 1 and Figure 2 As shown, it is composed of a water inlet area 1, a pretreatment area 2, a functional area 3 and a water outlet area 4 which are adjacent to each other from left to right.

[0066] The water inlet area 1 and the pretreatment area 2 are separated by a first partition 21, and a first water outlet 6 for connecting the water inlet area 1 and the pretreatment area 2 is provided at the lower end of the first partition 21. The pretreatment area 2 and the functional area 3 are separated by a second partition 22, and a second water outlet 8 for connecting the pretreatment area 2 and the functional area 3 is provided at the upper end of the second partition 22. The functional area 3 and the water outlet area 4 are separated by a third partition 23, and a third water outlet 12 for connecting the functional area 3 and the water outlet area 4 is provided at the lower end of the third partition 23. The first water outlet 6, the second water outlet 8 and the third water outlet 12 are all composed of a linear porous partition, which is evenly covered with through holes with an aperture of 2 mm. A water inlet 5 is provided at the upper left of the water inlet area 1, and a fourth water outlet 13 is provided at the upper right of the water outlet area 4. The fourth water outlet 13 is at the same height as the water inlet 5.

[0067] The interior of the pretreatment zone 2 is paved with nitrification filler 7, on which an aerobic nitrification biofilm is attached, which is used to remove ammonia nitrogen and reduce the dissolved oxygen content in the sewage through the aerobic nitrification of microorganisms; the nitrification filler 7 used in this embodiment is a zeolite filler with a particle size of 5-8 mm.

[0068] In the functional area 3, there are sulfur-free barrier filler layer 9, sulfur autotrophic denitrification filler layer 10 and sulfate removal filler layer 11 from top to bottom, wherein: the sulfur-free barrier filler layer 9 is composed of zeolite filler with a particle size of 5-8 mm, and the function of this layer is to prevent the sulfur and sulfate in the sulfur autotrophic denitrification filler layer 10 from directly contacting the plant roots and affecting the growth of plants. The sulfur autotrophic denitrification filler layer 10 is composed of a uniform mixture of limestone filler and sulfur filler, and a sulfur autotrophic denitrification biofilm is attached thereto; the particle size of the sulfur filler is 5-8 mm, and the function is to remove nitrate nitrogen by strengthening sulfur autotrophic denitrification; the particle size of the limestone filler is 20-30 mm, and the function is to adjust the pH to prevent the wastewater from being too acidic, thereby providing a suitable pH environment for the growth and metabolism of microorganisms in the sulfur autotrophic denitrification biofilm. The sulfate removal filler layer 11 is composed of square stones with a particle size of 20 to 30 mm and is attached with a sulfate-reducing microbial film. This layer is used to play a supporting role and remove sulfate generated by sulfur autotrophic denitrification; the top of the third water outlet 12 is at the same height as the top of the sulfate removal filler layer 11.

[0069] A denitrification plant area is provided above the pretreatment area 2 and the functional area 3. The denitrification plant area is composed of a soil layer 20 and denitrification plants 14 planted therein; the soil layer 20 is 5 cm thick and serves to fix the plant roots and provide nutrition; the denitrification plant used in this embodiment is calamus, and the planting density is 8 plants / m 2 Its functions are to remove nitrogen, provide carbon source and beautify the environment.

[0070] A water pump 17 is provided at the bottom of the water outlet area 4, and a flushing pipe 15 is provided at the top of the pretreatment area 2 and the functional area 3 and below the soil layer 20. The water pump 17 and the flushing pipe 15 are connected through a flushing water inlet pipe 24, and a first valve 16 is provided on the flushing water inlet pipe 24; the first valve 16 and the flushing water inlet pipe 24 are both located in the water outlet area 4; water distribution ports of different sizes are evenly opened on the lower surface of the flushing pipe 15, and the diameter of the water distribution ports is less than 5 mm. A sewage pipe 18 is provided at the bottom of the water inlet area 1, the pretreatment area 2 and the functional area 3, and sewage outlets of different sizes are evenly opened on the upper surface, and the diameter of the sewage outlets is less than 5 mm; one end of the sewage pipe 18 is located in the functional area 3, and the other end passes through the pretreatment area 2 and the water inlet area 1, opens outside the water inlet area 1, and is provided with a second valve 19.

[0071] The device operation process of this embodiment is as follows:

[0072] (1) After the sewage enters the water inlet 5 into the water inlet area 1, it enters the pretreatment area 2 from the first water outlet 6. Under the action of the nitrifying filler 7 and the aerobic nitrifying biofilm attached thereto, the ammonia nitrogen in the sewage is converted into nitrate through aerobic nitrification. In this process, the dissolved oxygen in the sewage is consumed. Since the sulfur autotrophic denitrification nitrogen removal efficiency is negatively correlated with the dissolved oxygen content, the sulfur autotrophic denitrification nitrogen removal efficiency in the subsequent functional area 3 can be improved.

[0073] (2) The effluent from the pretreatment area 2 enters the functional area 3 through the second outlet 8. When flowing through the sulfur autotrophic denitrification filler layer 10, sulfur autotrophic denitrification occurs under the action of the sulfur filler and the sulfur autotrophic denitrification biofilm, reducing the nitrate in the sewage to nitrogen gas. The sewage passing through the sulfur autotrophic denitrification filler layer 10 flows into the sulfate removal filler layer 11, and the sulfate generated during the sulfur autotrophic denitrification process is removed in this layer through ion exchange and the action of sulfate-reducing bacteria.

[0074] (3) When sewage flows through pretreatment zone 2 and functional zone 3, the roots of denitrifying plants can play a denitrifying role. At the same time, the carbon source from the root secretions can also provide a carbon source for the microorganisms in pretreatment zone 2, thereby improving the efficiency of aerobic nitrification.

[0075] (4) After passing through the functional area 3, the sewage has completed deep nitrogen removal, and the effluent from the functional area 3 enters the effluent area 4 through the third outlet 12 and is temporarily stored in the effluent area 4, which can be used to backwash the packing in the pretreatment area 2 and the functional area 3. The water in the effluent area 4 is discharged through the fourth outlet 13.

[0076] In the device of this embodiment, the packing in the pretreatment area 2 and the functional area 3 can be backwashed regularly to remove blockages in the gaps between the packings to avoid blockage of the device. The specific process is as follows: a water pump 17 is used to provide power for backwashing water pumping, and the water in the water outlet area 4 is pumped into the flushing pipe 15 through the flushing water inlet pipe 24, and then flows downward from the top of the pretreatment area 2 and the functional area 3 through the water distribution holes on the flushing pipe 15, taking away the blockages in the gaps between the packings, and after reaching the bottom of the pretreatment area 2 and the functional area 3, it is collected through the sewage outlet on the sewage pipe 18 and discharged through the sewage pipe 18.

[0077] Example 2

[0078] A constructed wetland anti-clogging deep nitrogen removal device, such as Figure 3 As shown, it is composed of a water inlet area 1, a pretreatment area 2, a functional area 3 and a water outlet area 4 which are adjacent to each other from left to right.

[0079] The water inlet area 1 and the pretreatment area 2 are separated by a first partition 21, and a first water outlet 6 for connecting the water inlet area 1 and the pretreatment area 2 is provided at the lower end of the first partition 21. The pretreatment area 2 and the functional area 3 are separated by a second partition 22, and a second water outlet 8 for connecting the pretreatment area 2 and the functional area 3 is provided at the upper end of the second partition 22. The functional area 3 and the water outlet area 4 are separated by a third partition 23, and a third water outlet 12 for connecting the functional area 3 and the water outlet area 4 is provided at the lower end of the third partition 23. The first water outlet 6, the second water outlet 8 and the third water outlet 12 are all composed of a folded-line porous partition, which is evenly covered with through holes with an aperture of 2 mm. A water inlet 5 is provided at the upper left of the water inlet area 1, and a fourth water outlet 13 is provided at the upper right of the water outlet area 4. The fourth water outlet 13 is at the same height as the water inlet 5.

[0080] The interior of the pretreatment area 2 is covered with nitrification fillers 7, on which aerobic nitrification biofilm is attached; the nitrification fillers 7 used in this embodiment are zeolite fillers with a particle size of 5-8 mm.

[0081] In the functional area 3, a sulfur-free barrier filler layer 9, a sulfur autotrophic denitrification filler layer 10 and a sulfate removal filler layer 11 are arranged in sequence from top to bottom, wherein: the sulfur-free barrier filler layer 9 is composed of a zeolite filler with a particle size of 5-8 mm; the sulfur autotrophic denitrification filler layer 10 is composed of a sulfur filler layer 25 and a limestone filler layer 26, the limestone filler layer 26 is located above the sulfur filler layer 25, and a sulfur autotrophic denitrification biofilm is attached to the sulfur filler layer 25, the particle size of the sulfur filler is 5-8 mm, and the particle size of the limestone filler is 20-30 mm; the sulfate removal filler layer 11 is composed of square stone with a particle size of 20-30 mm, and is attached with a sulfate-reducing microbial film, and the top of the third water outlet 12 is lower than the top of the sulfate removal filler layer 11.

[0082] A denitrification plant area is provided above the pretreatment area 2 and the functional area 3. The denitrification plant area is composed of a soil layer 20 and denitrification plants 14 planted therein; the thickness of the soil layer 20 is 5 cm; the denitrification plant used in this embodiment is calamus, and the planting density is 8 plants / m 2 .

[0083] A water pump 17 is provided at the bottom of the water outlet area 4, and a flushing pipe 15 is provided at the top of the pretreatment area 2 and the functional area 3 and below the soil layer 20. The water pump 17 and the flushing pipe 15 are connected through a flushing water inlet pipe 24, and a first valve 16 is provided on the flushing water inlet pipe 24; the first valve 16 and the flushing water inlet pipe 24 are both located in the water outlet area 4; a water distribution port with a diameter of 3 mm is evenly opened on the lower surface of the flushing pipe 15. A sewage pipe 18 is provided at the bottom of the water inlet area 1, the pretreatment area 2 and the functional area 3, and a sewage outlet with a diameter of 4 mm is evenly opened on its upper surface; one end of the sewage pipe 18 is located in the functional area 3, and the other end passes through the pretreatment area 2 and the water inlet area 1, opens outside the water inlet area 1, and is provided with a second valve 19.

[0084] Example 3

[0085] A constructed wetland anti-clogging deep nitrogen removal device, such as Figure 4 As shown, it is composed of a water inlet area 1, a pretreatment area 2, a functional area 3 and a water outlet area 4 which are adjacent to each other from left to right.

[0086] The water inlet area 1 and the pretreatment area 2 are separated by a first partition 21, and a first water outlet 6 for connecting the water inlet area 1 and the pretreatment area 2 is provided at the lower end of the first partition 21. The pretreatment area 2 and the functional area 3 are separated by a second partition 22, and a second water outlet 8 for connecting the pretreatment area 2 and the functional area 3 is provided at the upper end of the second partition 22. The functional area 3 and the water outlet area 4 are separated by a third partition 23, and a third water outlet 12 for connecting the functional area 3 and the water outlet area 4 is provided at the lower end of the third partition 23. The first water outlet 6, the second water outlet 8 and the third water outlet 12 are all composed of a folded line porous partition, wherein: the porous partition at the first water outlet 6 is evenly covered with through holes with a hole diameter of 2 mm; the porous partition at the second water outlet 8, the upper half is evenly covered with through holes with a hole diameter of 2.5 mm, and the lower half is evenly covered with through holes with a hole diameter of 1.5 mm; the porous partition at the third water outlet 12, the upper half is evenly covered with through holes with a hole diameter of 1.5 mm, and the lower half is evenly covered with through holes with a hole diameter of 2.5 mm. A water inlet 5 is provided at the upper left of the water inlet area 1, and a fourth water outlet 13 is provided at the upper right of the water outlet area 4, and the fourth water outlet 13 is at the same height as the water inlet 5.

[0087] The interior of the pretreatment area 2 is covered with nitrification fillers 7, on which aerobic nitrification biofilm is attached; the nitrification fillers 7 used in this embodiment are zeolite fillers with a particle size of 5-8 mm.

[0088] In the functional area 3, a sulfur-free barrier filler layer 9, a sulfur autotrophic denitrification filler layer 10 and a sulfate removal filler layer 11 are arranged in sequence from top to bottom, wherein: the sulfur-free barrier filler layer 9 is composed of a zeolite filler with a particle size of 5-8 mm; the sulfur autotrophic denitrification filler layer 10 is composed of a uniform mixture of limestone filler and sulfur filler, and a sulfur autotrophic denitrification biofilm is attached thereto, the particle size of the sulfur filler is 5-8 mm, and the particle size of the limestone filler is 20-30 mm; the sulfate removal filler layer 11 is composed of square stone with a particle size of 20-30 mm, and a sulfate-reducing microbial film is attached thereto, and the top of the third water outlet 12 is lower than the top of the sulfate removal filler layer 11.

[0089] A denitrification plant area is provided above the pretreatment area 2 and the functional area 3. The denitrification plant area is composed of a soil layer 20 and denitrification plants 14 planted therein; the thickness of the soil layer 20 is 5 cm; the denitrification plants used in this embodiment are cannas, and the planting density is 10 plants / m 2 .

[0090] A water pump 17 is provided at the bottom of the water outlet area 4, and a flushing pipe 15 is provided at the top of the pretreatment area 2 and the functional area 3 and below the soil layer 20. The water pump 17 and the flushing pipe 15 are connected through a flushing water inlet pipe 24, and a first valve 16 is provided on the flushing water inlet pipe 24; the first valve 16 and the flushing water inlet pipe 24 are both located in the water outlet area 4; a water distribution port with a diameter of 4 mm is evenly opened on the lower surface of the flushing pipe 15. A sewage pipe 18 is provided at the bottom of the water inlet area 1, the pretreatment area 2 and the functional area 3, and a sewage outlet with a diameter of 4 mm is evenly opened on its upper surface; one end of the sewage pipe 18 is located in the functional area 3, and the other end passes through the pretreatment area 2 and the water inlet area 1, opens outside the water inlet area 1, and is provided with a second valve 19.

[0091] Example 4

[0092] An artificial wetland anti-clogging deep nitrogen removal device, which differs from Example 2 only in the shape of the porous partitions at the first water outlet 6, the second water outlet 8 and the third water outlet 12. Specifically, the first water outlet 6, the second water outlet 8 and the third water outlet 12 are all composed of linear porous partitions. The rest of the structure is the same as that of Example 2.

[0093] Example 5

[0094] An anti-clogging deep nitrogen removal device for artificial wetlands, the difference from Example 2 is only in the aperture of the through holes on the porous partition at the second water outlet 8 and the third water outlet 12, specifically: on the porous partition at the second water outlet 8, the upper half is evenly covered with through holes with an aperture of 2.5 mm, and the lower half is evenly covered with through holes with an aperture of 1.5 mm; on the porous partition at the third water outlet 12, the upper half is evenly covered with through holes with an aperture of 1.5 mm, and the lower half is evenly covered with through holes with an aperture of 2.5 mm. The rest of the structure is the same as Example 2.

[0095] Unless otherwise specified, the devices, connection structures and methods involved in the present invention are all devices, connection structures and methods well known in the art.

[0096] The above description is only a preferred embodiment of the present invention and does not constitute any limitation to the present invention. Any simple modification, change and equivalent structural transformation made to the above embodiments according to the technical essence of the present invention shall still fall within the protection scope of the technical solution of the present invention.

Claims

1. An artificial wetland anti-clogging deep nitrogen removal device, characterized in that: The invention comprises a pretreatment area (2) and a functional area (3) which are interconnected; the pretreatment area (2) is filled with a nitrification filler (7), and an aerobic nitrification biofilm is attached to the nitrification filler (7); the functional area (3) is provided with a sulfur-free barrier filler layer (9), a sulfur autotrophic denitrification filler layer (10) and a sulfate removal filler layer (11) from top to bottom, and a sulfur autotrophic denitrification biofilm is attached to the sulfur autotrophic denitrification filler layer (10); and a denitrification plant area is provided above the pretreatment area (2) and the functional area (3).

2. The artificial wetland anti-clogging deep nitrogen removal device according to claim 1 is characterized in that: It also comprises a flushing pipe (15) and a sewage pipe (18); the flushing pipe (15) is arranged at the top of the pretreatment area (2) and the functional area (3), and is located below the denitrification plant area; the sewage pipe (18) is arranged at the bottom of the pretreatment area (2) and the functional area (3); a plurality of water distribution ports are arranged below the flushing pipe (15); and a plurality of sewage outlets are arranged above the sewage pipe (18).

3. The artificial wetland anti-clogging deep nitrogen removal device according to claim 2 is characterized in that: It also includes a water pump (17) for pumping the outlet water of the functional area (3) to the flushing pipe (15); the water pump (17) is connected to the flushing pipe (15) via a flushing water inlet pipe (24); and a first valve (16) is provided on the flushing water inlet pipe (24).

4. The artificial wetland anti-clogging deep nitrogen removal device according to claim 1 is characterized in that: It also comprises a water inlet area (1) and a water outlet area (4); the water inlet area (1) is interconnected with the pretreatment area (2); and the water outlet area (4) is interconnected with the functional area (3).

5. The artificial wetland anti-clogging deep nitrogen removal device according to claim 4 is characterized in that: The water inlet area (1) and the pretreatment area (2), the pretreatment area (2) and the functional area (3), and the functional area (3) and the water outlet area (4) are separated by a first partition plate (21), a second partition plate (22), and a third partition plate (23), respectively.

6. The artificial wetland anti-clogging deep nitrogen removal device according to claim 5 is characterized in that: The lower end of the first partition plate (21) is provided with a first water outlet (6) connecting the water inlet area (1) and the pretreatment area (2); the upper end of the second partition plate (22) is provided with a second water outlet (8) connecting the pretreatment area (2) and the functional area (3); and the lower end of the third partition plate (23) is provided with a third water outlet (12) connecting the functional area (3) and the water outlet area (4).

7. The artificial wetland anti-clogging deep nitrogen removal device according to claim 6 is characterized in that: The top of the third water outlet (12) is not higher than the top of the sulfate removal filler layer (11).

8. The artificial wetland anti-clogging deep nitrogen removal device according to claim 6, characterized in that: The first water outlet (6), the second water outlet (8) and the third water outlet (12) are all formed by porous partitions.

9. The artificial wetland anti-clogging deep nitrogen removal device according to claim 8, characterized in that: The porous partition is in a folded line shape; in the porous partition at the second water outlet (8), the aperture of the through hole at the upper end is larger than the aperture of the through hole at the lower end; in the porous partition at the third water outlet (12), the aperture of the through hole at the upper end is smaller than the aperture of the through hole at the lower end.

10. The artificial wetland anti-clogging deep nitrogen removal device according to claim 1, characterized in that: The sulfur autotrophic denitrification filler layer (10) is filled with limestone fillers, and sulfur fillers are dispersed between the limestone fillers; or, the sulfur autotrophic denitrification filler layer (10) comprises a sulfur filler layer (25) and a limestone filler layer (26) arranged above the sulfur filler.

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