CN215327545U

CN215327545U - Rural sewage treatment plant

Info

Publication number: CN215327545U
Application number: CN202120368415.XU
Authority: CN
Inventors: 何睦盈; 吴小龙; 朱凯; 李奇蓬
Original assignee: Guangzhou Meiya Energy Saving And Environmental Protection Co ltd
Current assignee: Guangzhou Meiya Energy Saving And Environmental Protection Co ltd
Priority date: 2021-02-08
Filing date: 2021-02-08
Publication date: 2021-12-28
Anticipated expiration: 2031-02-08

Abstract

The utility model relates to the technical field of water treatment, and discloses a rural sewage treatment device which comprises a slag separation tank, a drop ecosystem and an artificial wetland, wherein the drop ecosystem comprises a water storage tank, a water distribution tank, a circulating pump and a plurality of drop plates, the water distribution tank, the drop plates and the water storage tank are sequentially arranged from top to bottom, the circulating pump is arranged in the water storage tank, the circulating pump is communicated with the water distribution tank through a pipeline, the drop plates are obliquely and downwards arranged, a first biological packing layer is paved on the drop plates, the water storage tank is provided with a water inlet and a water outlet, the water inlet is communicated with the slag separation tank, and the water outlet is communicated with the artificial wetland, so that good conditions are provided for removing pollutants such as COD (chemical oxygen demand), total nitrogen and the like. When passing through the water drop plate, the sewage can be fully contacted with the first biological filler layer and the oxygen, the flow is kept, the purification efficiency is improved, and the ecological process is adopted, so that equipment is not needed, and the operation cost is reduced.

Description

Rural sewage treatment plant

Technical Field

The utility model relates to the technical field of water treatment, in particular to a rural sewage treatment device.

Background

Rural domestic sewage is discharged to peripheral water bodies randomly under the condition of not being effectively treated, so that the environmental sanitation condition is deteriorated, and the peripheral surface water, underground water and soil are seriously polluted, and further the rural drinking water safety is threatened. In order to accelerate the construction of beautiful villages, promote the sustainable development of the villages and meet the demand of farmers on good life, a feasible treatment technology is required to be adopted for the treatment of rural domestic sewage.

The domestic sewage treatment adopts two treatment methods, biological treatment and ecological treatment. Compared with biological treatment, the ecological treatment process has the characteristics of simple operation and maintenance and low operation cost, and is more suitable for remote areas with insufficient expenditure. The distributed ecological treatment process mainly comprises the artificial wetland, and the artificial wetland can remove pollutants through the combined action of plant absorption, microbial reaction, filler adsorption and the like. The removal of ammonia nitrogen requires the existence of oxygen, and compared with a horizontal flow artificial wetland, the vertical flow artificial wetland has better ammonia nitrogen removal effect; but the removal rate of Total Nitrogen (TN) is about 10-20%. At present, the total nitrogen removal effect is improved by increasing power equipment to provide backflow or building a horizontal flow artificial wetland after the backflow, but the operation cost and the occupied area are increased to different degrees.

Chinese utility model patent CN209740821U (published as 2019, 12 and 06) discloses a composite artificial wetland system for rural domestic sewage treatment, which comprises an inlet channel, an anaerobic baffling regulation tank, a vertical flow artificial wetland tank, a water receiving channel and an outlet well, which are connected in sequence and integrally constructed; a slag separation net is obliquely arranged in the water inlet channel; the bottom of the anaerobic baffling adjusting tank is provided with a bucket-shaped structure; a slag separation plate is arranged between the anaerobic baffling adjusting tank and the vertical flow artificial wetland tank; and the sewage purified by the vertical flow artificial wetland pool is converged into a water outlet well through the water collecting channel. This patent is through separating the sediment net with sewage, the anaerobism baffling equalizing basin, the artifical wetland pond of vertical current purifies, the anaerobism baffling equalizing basin is though can get rid of partly total nitrogen, but because the oxygen of above-mentioned system lacks, it is poor to lead to the ammonia nitrogen to get rid of the effect, and nitrate nitrogen produces inadequately, it is not good to cause anaerobism baffling equalizing basin denitrification denitrogenation effect, and the biochemical treatment time of anaerobism pond is very long moreover, the time that sewage need stop in the anaerobism pond is longer, inefficiency.

SUMMERY OF THE UTILITY MODEL

The utility model aims to provide a rural sewage treatment device with good purification effect and high efficiency.

In order to achieve the purpose, the utility model provides a rural sewage treatment device which comprises a slag separation tank, a drop ecosystem and an artificial wetland, wherein the drop ecosystem comprises a water storage tank, a water distribution tank, a circulating pump and a plurality of drop plates, the water distribution tank, the drop plates and the water storage tank are sequentially arranged from top to bottom, the circulating pump is arranged in the water storage tank, the circulating pump is communicated with the water distribution tank through a pipeline, the drop plates are obliquely arranged downwards, a first biological packing layer is paved on the drop plates, the water storage tank is provided with a water inlet and a water outlet, the water inlet is communicated with the slag separation tank, and the water outlet is communicated with the artificial wetland.

As preferred scheme, the drop board includes a plurality of first drop boards and second drop board, and a plurality of first drop boards are parallel arrangement from top to bottom in proper order, and is a plurality of second drop board is parallel arrangement from top to bottom in proper order, first drop board with the crisscross setting of second drop board, the bottom of first drop board is located rather than adjacent the clearance that sewage can pass through in order to form in the top of second drop board, the extension line of first drop board with rather than adjacent the second drop board is crossing.

Preferably, the drop ecosystem further comprises a second biological packing layer, the second biological packing layer is arranged in the water storage tank, the second biological packing layer divides the water storage tank into a first water storage tank and a second water storage tank, the circulating pump is arranged in the second water storage tank, and sewage flows into the first water storage tank through the water inlet and enters the second water storage tank through the second biological packing layer.

As a preferred scheme, a baffle is further arranged in the reservoir, two ends of the baffle are respectively connected with the inner wall of the reservoir, two side faces of the baffle, which are back to back, are respectively opposite to the water inlet and the water outlet, the baffle is close to the water outlet, and the circulating pump is located between the water inlet and the baffle, so that sewage between the water inlet and the baffle enters the space between the baffle and the water outlet from the lower part of the baffle.

Preferably, the artificial wetland comprises an ecological pool and at least one water purification unit, the ecological pool is provided with a water inlet and a water outlet, the water inlet is positioned at the top of the ecological pool, the water outlet is positioned at the bottom of the ecological pool, and the water purification unit is arranged in the ecological pool, so that sewage enters from the water inlet and flows through the water purification unit and then flows out from the water outlet.

According to a preferable scheme, the water purification unit comprises a filter material layer, a transition layer and a vent pipe, the filter material layer and the transition layer are arranged up and down, the vent pipe is arranged in the transition layer and communicated with the outside of the ecological pool, and a plurality of vent holes are formed in a pipe body of the vent pipe.

Preferably, the artificial wetland comprises two or more water purification units, and the water purification units are sequentially arranged in the ecological pool from top to bottom.

Preferably, the constructed wetland further comprises a covering layer, the covering layer is positioned above the water purification unit, and plants are planted on the covering layer.

As a preferred scheme, the artificial wetland also comprises a plurality of drain pipes, the drain pipes are uniformly laid in the ecological pool and are positioned above the water purification unit, and a plurality of drain holes are arranged on the pipe body of the drain pipes.

Preferably, the water inlet is provided with a switch valve.

Compared with the prior art, the utility model has the beneficial effects that:

the utility model leads sewage to be discharged after sequentially passing through the slag separating tank, the drop ecosystem and the artificial wetland by communicating the slag separating tank, the drop ecosystem and the artificial wetland, the slag separating tank can intercept large-particle pollutants, the artificial wetland can further intercept the pollutants and consume organic matters, the drop ecosystem lifts the sewage in the water storage tank into the water distribution tank through the circulating pump and then flows onto the drop plate from the water distribution tank, when the sewage passes through the drop plate, the water surface is contacted with air, oxygen is dissolved in the water flow, the surface layer, the middle layer and the bottom layer of the water flow form an aerobic, facultative and anaerobic relatively stable area which is matched with aerobic, facultative and COD microorganisms attached to the first biological packing layer, good conditions are provided for removing the pollutants such as denitrification, total nitrogen and the like, particularly good conditions are provided for biological denitrification, and the three-layer dissolved oxygen gradient is favorable for nitrification and denitrification, The aged thallus autolysis and anaerobic degradation products provide rich carbon sources for denitrification, guarantee the restrictive link of biological denitrification, and the denitrification is smoothly carried out. When passing through the water drop plate, the sewage can be fully contacted with the first biological filler layer and the oxygen, the flow is kept, the purification efficiency is improved, and the ecological process is adopted, so that equipment is not needed, and the operation cost is reduced.

Drawings

FIG. 1 is a schematic structural diagram of a rural sewage treatment plant according to an embodiment of the present invention.

Fig. 2 is a schematic structural diagram of a drop ecosystem according to an embodiment of the utility model.

Fig. 3 is a schematic structural view of the constructed wetland in the embodiment of the utility model.

In the figure, 100-slag removal tank; 200-a drop ecosystem; 210-a water reservoir; 211-a water inlet; 212-water outlet; 220-water distribution tank; 230-a circulating pump; 240-first bio-filler layer; 250-a first drop plate; 260-second drop plate; 270-a second bio-filler layer; 280-a baffle; 300-constructed wetland; 310-an ecological pool; 311-water inlet; 312-a drain opening; 320-a water purification unit; 321-a filter material layer; 322-a transition layer; 323-gas permeable tube; 330-a cover layer; 340-plants; 350-a drain pipe.

Detailed Description

The following detailed description of embodiments of the present invention is provided in connection with the accompanying drawings and examples. The following examples are intended to illustrate the utility model but are not intended to limit the scope of the utility model.

In the description of the present invention, it should be noted that the terms "center", "longitudinal", "lateral", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc., indicate orientations or positional relationships based on those shown in the drawings, and are only for convenience of description and simplicity of description, but do not indicate or imply that the referred device or element must have a specific orientation, be constructed and operated in a specific orientation, and thus, should not be construed as limiting the present invention.

In the description of the present invention, it should be noted that, unless otherwise explicitly specified or limited, the terms "mounted," "connected," and "connected" are to be construed broadly, e.g., as meaning either a fixed connection, a removable connection, or an integral connection; can be mechanically or electrically connected; they may be connected directly or indirectly through intervening media, or they may be interconnected between two elements. The specific meanings of the above terms in the present invention can be understood in specific cases to those skilled in the art.

In addition, in the description of the present invention, "a plurality" means two or more unless otherwise specified.

As shown in fig. 1 to 3, a rural sewage treatment apparatus according to a preferred embodiment of the present invention includes a slag trap 100, a drop ecosystem 200 and an artificial wetland 300, the drop ecosystem 200 includes a water storage tank 210, a water distribution tank 220, a circulation pump 230 and a plurality of drop plates, the water distribution tank 220, the drop plates and the water storage tank 210 are sequentially arranged from top to bottom, the circulation pump 230 is disposed in the water storage tank 210, the circulation pump 230 is communicated with the water distribution tank 220 through a pipeline, the drop plates are arranged obliquely downward, a first biological filler layer 240 is laid on the drop plates, the water storage tank 210 is provided with a water inlet 211 and a water outlet 212, the water inlet 211 is communicated with the slag trap 100, and the water outlet 212 is communicated with the artificial wetland 300. In the embodiment, the slag separating tank 100, the drop ecosystem 200 and the artificial wetland 300 are communicated, so that sewage is discharged after sequentially passing through the slag separating tank 100, the drop ecosystem 200 and the artificial wetland 300, the slag separating tank 100 can intercept large-particle pollutants, the artificial wetland 300 can further intercept pollutants and consume organic matters, the drop ecosystem 200 lifts the sewage in the water storage tank 210 to the water distribution tank 220 through the circulating pump 230 and then flows to the drop plate from the water distribution tank 220, when the sewage passes through the drop plate, the water surface is in contact with air to dissolve oxygen in the water flow, the surface layer, the middle layer and the bottom layer of the water flow form an aerobic, facultative and anaerobic relatively stable area, and the water flow cooperates with aerobic, facultative and anaerobic microorganisms attached to the first biological packing layer 240 to provide good conditions for removing pollutants such as COD, total nitrogen and the like, particularly for biological denitrification, and the three-layer dissolved oxygen gradient is beneficial to nitrification and denitrification, autolysis of aged thalli and providing rich carbon sources for denitrification by anaerobic degradation products, so that the restrictive link of biological denitrification is ensured, the denitrification is smoothly carried out, and in addition, the biological membrane can utilize natural light, so that the production of algae and photosynthetic bacteria is facilitated, and the decontamination effect is promoted. The sewage of this embodiment is when the board falls, and the surface of water is spread on the board falls, and the thickness of water layer is little, can be fully with first biological packing layer 240 and oxygen contact, keeps flowing, improves purification efficiency to all adopt ecological technology, need not equipment, reduce running cost. The first biological filler layer 240 of this embodiment is a rattan cotton layer, and three-layer rattan cotton piece from top to bottom superposes and forms first filter material layer, and three rattan cotton piece from top to bottom is good oxygen, facultative, anaerobic microorganisms in proper order and adheres to, and the rattan cotton can improve water quality and filter cleanly, and is the hotbed of nitrobacteria culture, is favorable to nitrifying and denitrification, has physics and biochemical filter effect concurrently.

Furthermore, the drop plate comprises a plurality of first drop plates 250 and a plurality of second drop plates 260, the plurality of first drop plates 250 are sequentially arranged in parallel from top to bottom, the plurality of second drop plates 260 are sequentially arranged in parallel from top to bottom, the first drop plates 250 and the second drop plates 260 are arranged in a staggered manner, the bottom ends of the first drop plates 250 are positioned above the adjacent second drop plates 260 to form gaps through which sewage can pass, the extension lines of the first drop plates 250 are intersected with the adjacent second drop plates 260, and first biological packing layers 240 are respectively paved on the first drop plates 250 and the second drop plates 260, so that multistage drop can be realized, oxygen is fully dissolved in the sewage, the distribution of aerobic organisms is improved, the flow path of the sewage is prolonged, and the purification is more sufficient.

In addition, drop ecosystem 200 still includes second bio-packing layer 270, second bio-packing layer 270 is located in cistern 210, second bio-packing layer 270 divide into first cistern and second cistern with cistern 210, the circulating pump is established 230 in the second cistern, make sewage flow into first cistern through water inlet 211 and get into in the second cistern through second bio-packing layer 270, it is limited to promote the sewage volume in water distribution groove 220 through circulating pump 230, it has most sewage to dwell in cistern 210, should second bio-packing layer 270 can purify the sewage in cistern 210, purifying effect and efficiency are improved. In addition, a baffle 280 is further arranged in the water reservoir 210, two ends of the baffle 280 are respectively connected with the inner wall of the water reservoir 210, two opposite side surfaces of the baffle 280 are respectively opposite to the water inlet 211 and the water outlet 212, the baffle 280 is arranged close to the water outlet 212, the circulating pump 230 is positioned between the water inlet 211 and the baffle 280, so that sewage positioned between the water inlet 211 and the baffle 280 enters between the baffle 280 and the water outlet 212 from the lower part of the baffle 280, the sewage can circulate in the water reservoir 210 and can be fully contacted with the second biological packing layer 240, and the purification effect is improved.

The artificial wetland 300 of the embodiment comprises an ecological pool 310 and at least one water purification unit 320, wherein the ecological pool 310 is provided with a water inlet 311 and a water outlet 312, the water inlet 311 is positioned at the top of the ecological pool 310, the water outlet 312 is positioned at the bottom of the ecological pool 310, and the water purification unit 320 is arranged in the ecological pool 310, so that sewage enters from the water inlet 311 and flows out from the water outlet 312 after flowing through the water purification unit 320, and as the water purification unit 320 in the ecological water purification system 300 has a large thickness, more facultative and anaerobic microorganisms are distributed, and less aerobic microorganisms are distributed, the arrangement of the water drop ecological system 200 can compensate for the problem, and is helpful for reducing the floor area of the artificial wetland 300. The water purification unit 320 comprises a filter material layer 321, a transition layer 322 and a vent pipe 323, the filter material layer 321 and the transition layer 322 are arranged up and down, the vent pipe 323 is arranged in the transition layer 322, the vent pipe 323 is communicated with the outside of the ecological pool 310, a plurality of vent holes are arranged on the pipe body of the vent pipe 323, so that air in the external environment can enter the transition layer 322 through the vent pipe 323, a multi-layer oxygen environment layer area of 'aerobic-anoxic-anaerobic-aerobic' is formed in the water purification unit 320 from top to bottom, the distribution of aerobic organisms is improved, a corresponding internal oxygen environment is provided for efficient degradation of pollutants by microorganisms of matrix fillers in each layer area, soil blocks can be avoided, and the breathing and growth of plants are facilitated. The precoat layer 321 of this embodiment includes inert organic components, sandy soil, loam, modifiers, and special fillers (trace elements). Further, the artificial wetland 300 comprises two or more water purification units 320, and each water purification unit 320 is arranged in the ecological pool 310 from top to bottom in sequence, so that multi-layer purification can be realized, and the purification effect is improved. Regarding the single water purification unit 320, after water inflow stops, water slowly infiltrates under the action of gravity, the main water level of the water surface also descends along with the water infiltration, when the water level falls below the filter material layer 321, certain negative pressure exists in the upper filter material layer at the upper main water level, and external fresh air slowly enters the soil layer under the action of the negative pressure. And positive pressure is formed in the lower layer filter material at the lower liquid level under the action of water pressure, so that gas products generated by decomposition in the lower layer soil at the lower liquid level are slowly discharged out through the built-in gas permeable pipe 323. When the upper liquid level drops to the second water purification unit 320, the above process is repeated, except that the external fresh air enters the soil layer through the built-in ventilation pipe 323. The oxygen content in the soil layer is effectively increased through the processes, good conditions are provided for rapid digestion of microorganisms in the filler and respiration of the plant root system, the problem of discharge of decomposed gas is solved, and the problems that the purification efficiency is reduced due to the influences of phenomena such as system blockage, reduction of microbial activity and plant root system poisoning caused by siltation in the filler are avoided. Further, the ecological water purification system 300 further includes a cover layer 330, the cover layer 330 is located above the water purification unit 320, the cover layer 330 is planted with plants 340, and a certain direct economic benefit is obtained by planting crops with a certain economic value. In the constructed wetland 300, the main purification functions are the abundant and huge types of microorganisms and substrate enzymes in the filter material, the adsorption and interception of the filter material substrate are performed, and the purification of the plants 340 plays an auxiliary role.

In addition, the constructed wetland 300 further comprises a plurality of drain pipes 350, the drain pipes 350 are uniformly laid in the ecological pool 310, the drain pipes 350 are positioned above the water purification unit 320, and a plurality of drain holes are arranged on the pipe body of the drain pipes 350, so that the wastewater can be uniformly distributed on the surface of the covering layer 330 and uniformly seeps into the water purification unit 320, and the utilization efficiency is improved. Furthermore, the water inlet is provided with a switch valve which can control the water inlet of the ecological water purification system, the water can be fed in for a period of time and stopped for a period of time, the dry-wet alternative water inlet mode is adopted, the phenomena of breeding a large amount of mosquitoes and causing stink which are common in a submerged artificial wetland system with continuous water inlet are avoided, and the plant maintenance and the residue collection are very convenient.

To sum up, the embodiment of the present invention provides a rural sewage treatment apparatus, which communicates a slag trap 100, a drop ecosystem 200 and an artificial wetland 300, so that sewage is discharged after sequentially passing through the slag trap 100, the drop ecosystem 200 and the artificial wetland 300, the slag trap 100 can intercept large-particle pollutants, the artificial wetland 300 can further intercept pollutants and consume organic matters, the drop ecosystem 200 lifts the sewage in a reservoir 210 to a water distribution tank 220 through a circulating pump 230, and then flows from the water distribution tank 220 to a drop plate, when the sewage passes through the drop plate, the water surface contacts with air, oxygen is dissolved in the water flow, the surface layer, the middle layer and the bottom layer of the water flow form a relatively stable area of aerobic, facultative and anaerobic, and the relatively stable area is matched with aerobic, microbial and aerobic microorganisms attached to a first biological filler layer 240, so as to provide good conditions for removing pollutants such as anaerobic COD, total nitrogen and the like, especially, good conditions are provided for biological denitrification, the three-layer dissolved oxygen gradient is favorable for nitrification and denitrification, the aged thallus autolysis and anaerobic degradation products provide rich carbon sources for denitrification, the restrictive link of biological denitrification is ensured, the denitrification is smoothly carried out, in addition, the biological membrane can utilize natural light, the production of algae and photosynthetic bacteria is favorable, and the decontamination effect is promoted. The sewage of this embodiment can be fully when falling the water board, keeps flowing with first biological packing layer 240 and oxygen contact, improves purification efficiency to all adopt ecological technology, need not equipment, reduce running cost.

The above description is only a preferred embodiment of the present invention, and it should be noted that, for those skilled in the art, various modifications and substitutions can be made without departing from the technical principle of the present invention, and these modifications and substitutions should also be regarded as the protection scope of the present invention.

Claims

1. A rural sewage treatment device is characterized by comprising a slag separating tank (100), a drop ecosystem (200) and an artificial wetland (300), the water drop ecosystem (200) comprises a water storage tank (210), a water distribution tank (220), a circulating pump (230) and a plurality of water drop plates, the water distribution groove (220), the water dropping plate and the water storage tank (210) are sequentially arranged from top to bottom, the circulating pump (230) is arranged in the water storage tank (210), the circulating pump (230) is communicated with the water distribution tank (220) through a pipeline, the water dropping plate is arranged downwards in an inclined way, a first biological packing layer (240) is paved on the water dropping plate, the water reservoir (210) is provided with a water inlet (211) and a water outlet (212), the water inlet (211) is communicated with the slag separating tank (100), and the water outlet (212) is communicated with the artificial wetland (300).

2. The rural sewage treatment device according to claim 1, wherein the water dropping plate comprises a plurality of first water dropping plates (250) and second water dropping plates (260), the plurality of first water dropping plates (250) are arranged in parallel from top to bottom, the plurality of second water dropping plates (260) are arranged in parallel from top to bottom, the first water dropping plates (250) and the second water dropping plates (260) are arranged in a staggered manner, the bottom end of each first water dropping plate (250) is positioned above the adjacent second water dropping plate (260) to form a gap through which sewage can pass, and the extension line of each first water dropping plate (250) is intersected with the adjacent second water dropping plate (260).

3. The rural sewage treatment plant according to claim 1, wherein the drop ecosystem (200) further comprises a second bio-packing layer (270), the second bio-packing layer (270) is disposed in the water reservoir (210), the second bio-packing layer (270) divides the water reservoir (210) into a first water reservoir (210) and a second water reservoir (210), and the circulation pump (230) is disposed in the second water reservoir (210) to allow sewage to flow into the first water reservoir (210) through the water inlet (211) and to enter the second water reservoir (210) through the second bio-packing layer (270).

4. The rural sewage treatment device according to claim 1, wherein a baffle (280) is further disposed in the water reservoir (210), two ends of the baffle (280) are respectively connected to an inner wall of the water reservoir (210), two opposite sides of the baffle (280) are respectively opposite to the water inlet (211) and the water outlet (212), the baffle (280) is disposed near the water outlet (212), and the circulation pump (230) is disposed between the water inlet (211) and the baffle (280) so that sewage between the water inlet (211) and the baffle (280) enters between the baffle (280) and the water outlet (212) from below the baffle (280).

5. The rural sewage treatment device according to claim 1, wherein the artificial wetland (300) comprises an ecological pool (310) and at least one water purification unit (320), the ecological pool (310) is provided with a water inlet (311) and a water outlet (312), the water inlet (311) is positioned at the top of the ecological pool (310), the water outlet (312) is positioned at the bottom of the ecological pool (310), and the water purification unit (320) is arranged in the ecological pool (310), so that sewage enters from the water inlet (311) and flows through the water purification unit (320) and then flows out from the water outlet (312).

6. The rural sewage treatment device according to claim 5, wherein the water purification unit (320) comprises a filter material layer (321), a transition layer (322) and a vent pipe (323), the filter material layer (321) and the transition layer (322) are arranged up and down, the vent pipe (323) is arranged in the transition layer (322), the vent pipe (323) is communicated with the outside of the ecological pool (310), and a plurality of vent holes are arranged on a pipe body of the vent pipe (323).

7. The rural sewage treatment plant according to claim 5, wherein the artificial wetland (300) comprises two or more water purification units (320), and each water purification unit (320) is arranged in the ecological pool (310) from top to bottom in sequence.

8. The rural sewage treatment plant according to claim 5, wherein the constructed wetland (300) further comprises a cover layer (330), the cover layer (330) is positioned above the water purification unit (320), and the cover layer (330) is planted with plants (340).

9. The rural sewage treatment device according to claim 5, wherein the constructed wetland (300) further comprises a plurality of drainage pipes (350), the drainage pipes (350) are uniformly laid in the ecological pool (310), the drainage pipes (350) are positioned above the water purification unit (320), and a plurality of drainage holes are arranged on the pipe body of the drainage pipes (350).

10. The rural sewage treatment plant according to claim 5, wherein a switch valve is arranged at the water inlet (311).