CN212025107U - Artificial wetland system of high-efficient undercurrent - Google Patents

Abstract

The utility model provides an artificial wetland system of high-efficiency undercurrent, which comprises a multifunctional combined pool and a wetland unit, wherein sewage firstly intercepts suspended matters and floating impurities in the multifunctional combined pool and carries out hydrolytic acidification on a water body; and then filtering and biodegrading in the wetland unit, uniformly distributing water by adopting a drip irrigation system, dredging by adopting a membrane guide system, and purifying the water body.The utility model discloses an artificial wetland system can be adapted to villages and small towns domestic sewage discharge's characteristics, carries out sewage purification, is applicable to the treatment scale and is not higher than 500m³A/d efficient undercurrent artificial wetland treatment system for treating sewage in villages and towns.

Description

An Efficient Underwater Constructed Wetland System

technical field

The utility model relates to the technical field of high-efficiency subsurface flow artificial wetlands, in particular to a high-efficiency subsurface flow artificial wetland system used for village sewage treatment.

Background technique

Domestic sewage in villages and towns has the characteristics of scattered discharge sources, weak people's awareness of environmental protection, insufficient facilities and economic conditions, large regional differences, large changes in villages and towns sewage, and difficult operation of biochemical processes. Therefore, it is of great theoretical and practical significance to develop and popularize the village sewage treatment system that adapts to the characteristics and economic strength of the villages and towns in my country.

Constructed wetland is a sewage treatment technology developed in the late 1970s. Its characteristics are: good effluent quality, strong nitrogen and phosphorus treatment capacity, convenient operation and maintenance, simple management, and low investment and operating costs. According to relevant data, the investment and operating costs of constructed wetlands only account for 10% to 50% of the traditional secondary biochemical treatment technology. It is more suitable for small and medium-sized towns and villages with less capital, energy shortage and lack of technical personnel, and small communities with uncompleted sewage pipe networks at the junction of urban and suburban areas.

Constructed wetland treatment system is a system in which sewage is put into wetlands in a controlled manner, so that sewage flows in a certain direction, and through the physical, chemical and biological interaction of soil, artificial media, plants and microorganisms, to achieve sewage purification. The body of water flows out at the terminal. Constructed wetlands in the traditional sense are generally operated as advanced treatment after biochemical systems. The constructed wetland of this utility model can be independently used as a technical system for efficient water pollution control, not just as advanced treatment application technology. The application of sewage in villages and towns in my country is maturing.

The water flow state of the constructed wetland system is an important factor to maintain the normal operation of the system and enable the system to give full play to the purification effect. However, after the blockage occurs, the permeability coefficient of the matrix will drop sharply, and the water passing capacity will also decrease. A large amount of sewage is introduced into the wetland system. It is directly accumulated on the wetland surface, and the long-term accumulation of water will cause foul odor, lead to the breeding of mosquitoes and flies, and deteriorate the operating environment; Yongshui also blocks the diffusion of oxygen into the matrix layer, thereby reducing the removal effect of pollutants (especially organic matter and ammonia nitrogen), making the effluent water The indicators do not meet the design standards, and at the same time, the operating life of the constructed wetland is shortened.

Constructed wetlands generally cover a large area, with low hydraulic load and poor operation in winter. The patented technology developed in this utility model mainly solves the problem of large area of constructed wetlands, poor adjustment ability, easy blockage, and poor operation effect of wetlands in winter. question.

In response to the above difficulties, based on in-depth research on traditional constructed wetlands, we have developed a high-efficiency subsurface-flow constructed wetland treatment system suitable for the treatment of villages and towns with a scale of not more than 500m ³ /d according to the characteristics of the composition of sewage.

Utility model content

The purpose of the present utility model is to solve the above problems, and provide a high-efficiency subsurface-flow constructed wetland system that can adapt to the characteristics of sewage treatment of villagers and towns.

In order to achieve the above purpose, the technical scheme adopted by the present utility model is as follows:

A high-efficiency subsurface constructed wetland system includes a multifunctional combined pool and a wetland unit. The sewage first intercepts suspended solids and floating impurities in the multifunctional combined pool, and hydrolyzes and acidifies the water body; Degradation, the drip irrigation system is used to distribute water evenly, and the membrane guide system is used to discharge silt and purify the water body.

Further, the multifunctional combined pool is divided into upper and lower two-layer structures, the upper layer structure is a grid pool with two grids, one grid is a mechanical grid, and the other grid is an artificial grid, which retains suspended matter and floating matter impurities; the lower layer structure is In the hydrolysis and acidification adjustment tank, the effluent from the upper grille tank flows to the bottom of the hydrolysis and acidification tank by gravity through the baffle plate in the tank, and is hydrolyzed by the acidic bacteria in the tank. There is a lift pump in 2/3 of the multi-functional combined tank to extract sewage.

Further, a three-dimensional elastic composite filler is arranged in the hydrolysis and acidification adjustment tank, and the agitated waste water is hydraulically cut, and the filler material is polypropylene and/or polyethylene.

Further, a plurality of funnel-shaped collectors are arranged at the bottom of the multifunctional combined tank to discharge the collected sludge regularly.

Further, a suction self-cleaning mesh filter is arranged between the multi-functional combined pool and the wetland unit, including the filter body, the coarse filter, the fine filter chamber, the flush valve and the flush controller. After the suction self-cleaning mesh filter The sewage is first filtered through the coarse filter screen and the fine filter screen, and the pollutants larger than 100 μm are retained on the filter screen, and the effluent enters the wetland unit. The backwash water is sucked in to wash the filter screen dirt by the change of pressure difference, and it is discharged through the flush valve.

Further, a polyethylene geotextile layer, a first coarse sand layer, a first gravel layer, a steel mesh layer, a second gravel layer, a second coarse sand layer, and a planting soil layer are sequentially laid in the wetland unit from bottom to top.

Further, the polyethylene geotextile layer is laid with a polyethylene plastic film with a thickness of 0.5mm, and a geotextile with a density of 500g/m2 is lined on both sides; the thickness of the first coarse sand layer is 100mm, and the first The thickness of the gravel layer is 500mm, and the particle size of the gravel is φ100-150mm; the diameter of the wire mesh layer is 10*10mm, and the diameter of the steel wire is 0.6mm; the thickness of the second gravel layer is 200mm, and the particle size of the gravel is φ10-15mm ; The thickness of the second coarse sand layer is 200mm; the thickness of the planting soil layer is 200mm, and the planting soil layer is used for planting aquatic plants.

Further, the constructed wetland system is sequentially connected by several wetland units.

Further, the drip irrigation system of the wetland unit is laid on the second gravel layer, a water distribution main pipe enters the wetland unit, and two water distribution branch pipes are laid in parallel in the wetland unit, and the water distribution branch pipes use a patch type drip irrigation belt. The patch-type drip irrigation tape includes patches, turbulent channels, and filter windows that are connected in sequence.

Further, the guide membrane system of the wetland unit is that the Fengzi water collection pipes are laid on the first gravel layer, the diameter of the water collection holes is φ20mm, and the spacing between the parallel water collection pipes is 150mm.

Further, the constructed wetland system is used for the purification treatment of domestic sewage in villages and towns.

A sewage treatment method, the domestic sewage is flowed into the multifunctional combined pool, the mechanical grille or the artificial grille works at intervals according to the needs of scouring, and the lifting pump cleans the sewage in the combined pool once every 3 hours;

The number of wetland units used is selected according to the requirements of the liquid level height. In summer, high liquid level operation is selected, and the liquid level reaches the plants on the planting soil layer. In spring and autumn, medium liquid level operation is selected, and the liquid level reaches the second coarse sand layer. In winter Select low liquid level operation in section, and the liquid level reaches the second gravel layer;

In the initial stage of operation of the wetland unit, open the outlet valve of the water collection pipe, and the accumulated materials adsorbed by each layer of sewage are discharged through the water collection pipe;

In the late stage of operation of the wetland unit, close the outlet valve of the water collection pipe, the hydraulic retention time of sewage in the wetland unit is 24 hours, the aging biofilm of each layer falls off into the water, and the outlet valve of the water collection pipe is opened instantly, and the aging biofilm falls off and enters the guiding membrane system. Discharge from the constructed wetland system.

Adopting the above-mentioned technical scheme, the utility model has the following beneficial effects:

First, the constructed wetland system of the present utility model can adapt to the characteristics of domestic sewage discharge in villages and towns for sewage purification treatment, and is suitable for a high-efficiency subsurface flow constructed wetland treatment system for village sewage treatment with a treatment scale of not more than 500 m ³ /d.

Second, the multifunctional combined pool of the present utility model can adjust the instantaneous change of water quality and quantity; improve the biodegradability of wastewater, and convert macromolecular organic matter into small molecules; the design flexibility of the pool body is high, and the water quality can be adjusted according to the quality of the incoming water. Requirement combination, transformed into other functional pools.

Third, the wetland unit of the present invention can flexibly adjust the number of wetland units used, and the wetland unit occupies a small area and has a high hydraulic load, which can adapt to the environmental problems of overwintering in winter, effectively prevent the blockage of the wetland, keep the wetland water unobstructed, and purify the wetland. strong ability.

Fourth, this patent uses a drip irrigation system to distribute water evenly, improve the efficiency of wetland treatment, ensure that the pollution load placed on the wetland is consistent, prevent the occurrence of short-circuit flow and dead water area, and slow down the blockage of the wetland. The guiding membrane system can regularly discharge the sediment, retentate and peeling biofilm produced during the operation of the wetland to the wetland unit to ensure the smooth flow of water in the wetland.

Description of drawings

Fig. 1 is the structural representation of the artificial wetland system of the present invention;

2 is a schematic structural diagram of the drip irrigation system and the film guiding system of the wetland unit of the present invention;

3 is a schematic diagram of the laying structure of the wetland unit of the present invention;

4 is a schematic structural diagram of the drip irrigation belt of the present invention.

Among them, 1. Multifunctional combined pool, 2. Suction self-cleaning mesh filter, 3. Wetland unit, 4. Grille pool, 5. Hydrolysis and acidification adjustment pool, 6. Drip irrigation system, 61. Patch, 62. Turbulence Flow channel, 63, filter window, 7, film guide system

In order to make the purpose, technical solutions and advantages of the present utility model more clearly understood, the present utility model will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the structural diagrams and specific embodiments described herein are only used to explain the present invention, and are not intended to limit the present invention.

Detailed ways

Example 1

As shown in Figure 1, a high-efficiency subsurface constructed wetland system includes a multi-functional combined pool 1 and a wetland unit 3. The sewage first intercepts suspended solids and floating impurities in the multi-functional combined pool, and hydrolyzes and acidifies the water body; The wetland unit is filtered and biodegraded, the drip irrigation system 6 is used to distribute water evenly, and the membrane guide system 7 is used to discharge silt and purify the water body.

The multi-functional combined pool is divided into upper and lower two-layer structures. The upper structure is a grid pool 4 with two grids. One grid is a mechanical grid and the other is an artificial grid, which retains suspended solids and floating impurities. The lower layer structure is hydrolysis and acidification adjustment. Pool 5, the effluent from the upper grid pool flows to the bottom of the hydrolysis and acidification pool by gravity through the baffles in the pool, so that the whole pool is in a state of complete mixing, and the residence time and rising flow rate of the hydrolysis and acidification pool are controlled, so that the reaction is in the acidification stage, and the hydrolysis reaction relies on acidification. The extracellular enzymes of bacteria are completed, and 2/3 of the multi-functional combined pool is equipped with a lift pump to extract sewage.

A three-dimensional elastic composite filler is arranged in the hydrolysis and acidification adjustment tank, and the agitated waste water is hydraulically cut, and the filler material is polypropylene and/or polyethylene. The agitated wastewater is hydraulically cut to prolong the hydraulic retention time, so that the suspended sludge can be fully mixed with water. Provide favorable conditions for the growth of hydrolytic acidification bacteria. The combined filler is fixed in the hydrolysis and acidification adjustment tank through the outer frame welded by angle steel, and the filler is fixed at a position 1m away from the bottom of the tank.

Preferably, a plurality of funnel-shaped collectors are also arranged at the bottom of the multifunctional combined tank to discharge the collected sludge regularly.

A suction self-cleaning mesh filter 2 is arranged between the multi-functional combined pool and the wetland unit, including a filter body, a coarse filter, a fine filter chamber, a flush valve and a flush controller. After the suction self-cleaning mesh filter The sewage is first filtered through the coarse filter screen and the fine filter screen, and the pollutants larger than 100μm are retained on the filter screen, and the effluent enters the wetland unit. When the pressure difference between the inside and outside of the filter screen is greater than the preset value, the controller opens the flushing valve, and the flow through the The change of pressure difference sucks in backwash water to wash the filter screen dirt and discharges it through the flush valve.

After the water flow enters the suction self-cleaning mesh filter, it first passes through the coarse filter screen, and then enters the fine filter chamber. The fine filter screen intercepts pollutants larger than 100um, and the effluent is purified water. The use of this filter reduces the use of constructed wetlands. The blockage of the constructed wetland will delay the replacement cycle of the constructed wetland filler.

Dirt collects on the fine screen, creating a pressure difference between the inner and outer surfaces of the screen. When the differential pressure reaches the preset value, the self-cleaning cycle starts. The differential pressure sensor transmits the signal to the controller to trigger it to open the flush valve, so that the pressure in the hydraulic motor chamber, the dirt collector and the suction nozzle is reduced to be open to the atmosphere. Causes the pressure difference between the inner surface of the fine filter screen (sewage) opposite the suction nozzle and the outside of the fine filter screen (clean water), and generates a strong suction backwash water to clean the dirt on the filter screen opposite the suction nozzle. Flush valve drains.

When the backwash water passes through the hydraulic motor, it drives the dirt collector to rotate, so that the suction nozzle can suck up and clean the dirt on the entire filter screen. When the filter screen is cleaned, the controller closes the flush valve, and the equipment automatically returns to the full filter state. The entire backwashing process takes only a few seconds, and the main flow is uninterrupted during this period, and there is no need to replace the filter element. The flushing water is only 1% of the mainstream.

Example 2

As shown in Figures 2 and 3, polyethylene geotextile layer, first coarse sand layer, first gravel layer, steel mesh layer, second gravel layer, second coarse sand layer, and planting soil layer are laid in the wetland unit from bottom to top. .

Wherein, the polyethylene geotextile layer is laid with polyethylene plastic film with a thickness of 0.5mm, and a geotextile with a density of 500g/m2 is lined on both sides; the thickness of the first coarse sand layer is 100mm, and the first gravel layer is The thickness of the second gravel layer is 500mm, and the particle size of the gravel is φ100-150mm; the diameter of the steel mesh layer is 10*10mm, and the diameter of the steel wire is 0.6mm; the thickness of the second gravel layer is 200mm, and the particle size of the gravel is φ10-15mm; The thickness of the second coarse sand layer is 200mm; the thickness of the planting soil layer is 200mm, and the planting soil layer is used for planting aquatic plants.

The constructed wetland system is sequentially connected by a number of wetland units. In the traditional sense, the hydraulic retention time of the submerged vertical flow constructed wetland is 3-5d. The hydraulic retention time of the wetland unit of the present invention is 1d, which greatly reduces the floor space and greatly increase the hydraulic load.

The drip irrigation system of the wetland unit is laid on the second gravel layer. A water distribution main pipe enters the wetland unit, and two water distribution branch pipes are laid in parallel in the wetland unit. The water distribution branch pipes use a patch type drip irrigation belt. It includes patches 61 , turbulent channels 62 , and filter windows 63 that are connected in sequence.

The water in the drip irrigation belt first flows through the patch, and after flowing through the turbulent channel, it enters the filter window and then exits through the dripper. The dripper flow channel is a turbulent flow channel, as shown in Figure 4, the water drips uniformly from one stable state to another stable state, which can achieve uniform irrigation, and the dripper has a filter window, which has good anti-blocking performance. Different crops and different soils can be obtained by replacing the dripper mold. Drip irrigation belts with different dripping properties are easy to achieve refined and precise irrigation. Drip irrigation belts use plastic pipes to send water to the roots of crops through orifices or drippers on capillary tubes with a diameter of about 10mm for local irrigation. The patch type drip irrigation belt is an integrated drip irrigation belt with a flat-shaped dripper embedded on the inner wall of the pipe belt. The drip hole of the patch type drip irrigation belt is completed by a mechanical punching method. No residue residue. Dripper, pipeline integrity is strong.

At the same time, when the drip irrigation belt is laid, the water outlet of the dripper can be artificially turned upward. After the water is passed through, the proportion of impurities contained in the water is greater than that of the water, and the impurities will sink at the bottom of the drip irrigation belt. Can cause the dripper to clog. It can not only ensure the reliability of the system operation, but also simplify the structure of the filter device and reduce the high cost of water quality treatment.

The guiding membrane system of the wetland unit is a Fengzi water collection pipe laid on the first gravel layer. The diameter of the water collection hole is φ20, and the distance between the water collection pipes arranged in parallel is 150mm. The guiding film system discharges silt for water purification.

The constructed wetland system is used for the purification and treatment of domestic sewage in villages and towns. In view of the non-uniformity of residents' water use at the junction of villages and towns and suburban areas, a multi-functional combined pool is set up to adjust the amount of sewage. From 6:00 to 8:00 and from 17:00 to 20:00 in the afternoon, the flow rate is the largest, and the water consumption time at the maximum time point generally does not exceed 3 hours. The design adjustment time of this multi-functional combined pool is 3 hours, so as to timely alleviate the pollution of sewage during peak water consumption. Collection, a lift pump is installed in the combined tank, and the sewage in the adjustment tank can be emptied in time before the peak time of water consumption.

The inlet water of the constructed wetland system of the utility model is the outlet water after the suction self-cleaning mesh filter, the water quality parameters are pH 6-7.2, DO is 0.01-0.05, TSS is 45-62mg/L, and CODcr is 124-200mg /L, BOD5 is 66-96mg/L, TN is 65-75mg/L, NH4-N is 30.5-45mg/L, TP is 4.8-5.3mg/L.

During the operation of the system, the continuous water inflow method was adopted, and the wetland unit was operated for more than 12 months. The effects of effluent pH and DO were 6.9-7.2 and 3.9-4.9 mg/L, respectively. Among them, TSS removal rate is 50-70%, CODcr removal rate is 52.3-72.5%, BOD5 removal rate is 51-70.4%, TN removal rate is 26.3-43.9%, NH4-N removal rate is 56.4-85.4%, TP removal rate is 85- 94.8%.

Example 3

In the early stage of the operation of the constructed wetland, the fine clay particles in the filler and many deposited SS together form a dense and impermeable layer, and the extracellular polymer continuously coagulates and adsorbs the suspended or colloidal substrates of different particle sizes, thereby forming a large particle size. The floc-like accumulation causes the co-accumulation of organic matter and inorganic matter, which blocks the pores of the filler. It is necessary to export the aging and falling off biofilm system in time. The biofilm is discharged from the wetland unit to ensure the smooth flow of water in the wetland. When the membrane guide device is activated, close the valve on the outlet pipe in the water collection tank of the constructed wetland, so that the filler in the wetland is in a state of full water infiltration, and the hydraulic infiltration time is 24h, so that the aging biofilm on the filler is more likely to fall off into the water, and then open the valve instantly, Under the impact of the pressurized water flow in the constructed wetland, the aging biofilm falls off into the guiding membrane system, that is, the water collection system, and is introduced into the water collection tank and discharged from the constructed wetland system.

The utility model provides a sewage treatment method using a constructed wetland system: the domestic sewage is flowed into the multifunctional combined pool, the mechanical grille or the artificial grille works at intervals according to the needs of cleaning, and the lifting pump is combined at an interval of 3 hours. The sewage in the pool is pumped once;

The number of wetland units used is selected according to the requirements of the liquid level height. In summer, high liquid level operation is selected, and the liquid level reaches the plants on the planting soil layer. In spring and autumn, medium liquid level operation is selected, and the liquid level reaches the second coarse sand layer. In winter Select low liquid level operation in section, and the liquid level reaches the second gravel layer;

In the initial stage of operation of the wetland unit, open the outlet valve of the water collection pipe, and the accumulated materials adsorbed by each layer of sewage are discharged through the water collection pipe;

In the late stage of operation of the wetland unit, close the outlet valve of the water collection pipe, the hydraulic retention time of sewage in the wetland unit is 24 hours, the aging biofilm of each layer falls off into the water, and the outlet valve of the water collection pipe is opened instantly, and the aging biofilm falls off and enters the guiding membrane system. Discharge from the constructed wetland system.

The influent of this high-efficiency subsurface constructed wetland system is municipal sewage in a suburb of Liaoning City, with water quality parameters of pH 7.2-8.0 and DO of 0.03-0.13. Sewage treatment is carried out using the above method.

In the high-efficiency subsurface constructed wetland system running for more than 12 months, the effects of effluent pH and DO are: 6.9-7.2, 3.9-4.9mg/L. Among them, the removal rate of TSS is 85-92.2%, the removal rate of CODcr is 86.7-94.6%, the removal rate of BOD5 is 83.2-90.3%, the removal rate of TN is 35%, the removal rate of NH4-N is 78.6-86.2%, and the removal rate of TP is 85-95%. .

The above-mentioned embodiments only represent the embodiments of the present invention, and the descriptions thereof are specific and detailed, but should not be construed as limiting the scope of the present invention. It should be pointed out that for those of ordinary skill in the art, some modifications and improvements can be made without departing from the concept of the present invention, which all belong to the protection scope of the present invention. Therefore, the protection scope of the patent for this utility model shall be subject to the appended claims.

Claims (11)

1. An artificial wetland system with high-efficiency subsurface flow comprises a multifunctional combined pool and wetland units, and is characterized in that sewage firstly intercepts suspended matters and floating impurities in the multifunctional combined pool and carries out hydrolytic acidification on a water body; and then filtering and biodegrading in the wetland unit, uniformly distributing water by adopting a drip irrigation system, dredging by adopting a membrane guide system, and purifying the water body.

2. The constructed wetland system of claim 1, wherein the multifunctional combined tank is divided into an upper layer structure and a lower layer structure, the upper layer structure is a two-lattice grating tank, one lattice is a mechanical grating, the other lattice is an artificial grating, and suspended matters and floating impurities are intercepted; the lower structure is a hydrolysis acidification adjusting tank, the effluent of the upper grid tank flows to the bottom of the hydrolysis acidification tank through the gravity of a baffle plate in the tank, the effluent is hydrolyzed through acidic bacteria in the tank, and a lifting pump is arranged at 2/3 of the position in the multifunctional combined tank to pump sewage.

3. The constructed wetland system of claim 2, wherein a three-dimensional elastic combined filler is arranged in the hydrolysis acidification adjusting tank to perform hydraulic cutting on the stirred wastewater, and the filler is made of polypropylene and/or polyethylene.

4. The constructed wetland system of claim 2, wherein a plurality of funnel-shaped collectors are provided at the bottom of the multipurpose composite tank, and the collected sludge is periodically discharged.

5. The constructed wetland system of claim 2, wherein a suction self-cleaning screen filter is disposed between the multifunctional assembled tank and the wetland unit, and comprises a filter body, a coarse filter screen, a fine filter chamber, a flushing valve and a flushing controller, wherein the sewage passing through the suction self-cleaning screen filter is firstly filtered by the coarse filter screen and the fine filter screen in two stages, the pollutants larger than 100 μm are trapped on the filter screen, the effluent enters the wetland unit, and when the pressure difference between the inside and the outside on the filter screen is larger than a preset value, the controller opens the flushing valve, so that the sewage is flushed by the backwashing water through the filter screen and is discharged through the flushing valve.

6. The constructed wetland system of claim 1, wherein the wetland unit is sequentially paved with a polyethylene geotextile layer, a first coarse sand layer, a first gravel layer, a steel wire mesh layer, a second gravel layer, a second coarse sand layer and a planting soil layer from bottom to top.

7. The constructed wetland system of claim 6, wherein the polyethylene geotextile layer is laid with a polyethylene plastic film having a thickness of 0.5mm and a liner density of 500g/m on both sides²The geotextile of (1); the thickness of the first coarse sand layer is 100mm, the thickness of the first gravel layer is 500mm, and the particle diameter of gravel is phi 100-150 mm; the aperture of the steel wire mesh layer is 10 x 10mm, and the diameter of the steel wire is 0.6 mm; the thickness of the second gravel layer is 200mm, and the particle size of the gravel is phi 10-15 mm; the thickness of the second coarse sand layer is 200 mm; the thickness of planting the soil layer is 200mm, plants aquatic plants in the soil layer.

8. The constructed wetland system of claim 6, wherein the constructed wetland system is composed of a plurality of wetland units which are connected in sequence.

9. The constructed wetland system of claim 8, wherein the drip irrigation system of the wetland unit is laid on the second gravel layer, enters the wetland unit from a main water distribution pipe, and is laid in the wetland unit in parallel from two branch water distribution pipes, the branch water distribution pipes are patch-type drip irrigation belts, and each patch-type drip irrigation belt comprises a patch, a turbulent flow channel and a filter window which are sequentially communicated.

10. The constructed wetland system of claim 9, wherein the membrane guide system of the wetland unit is a Chinese character feng water collecting pipe laid on the first gravel layer, the aperture of the water collecting hole is phi 20mm, and the distance between the water collecting pipes arranged in parallel is 150 mm.

11. The constructed wetland system of any one of claims 1 to 10, wherein the constructed wetland system is used for purifying domestic sewage in villages and towns.

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