CN110540298A - A Constructed Wetland System Using Dredging Tubes to Prevent Blockage - Google Patents

Abstract

The invention discloses an anti-clogging submerged flow artificial wetland system. The water inlet pipe is connected with the water distribution area, the wetland treatment area is connected with the water distribution area, the water outlet pipe is connected with the water collection area, and the mud discharge pipe is respectively connected with the wetland treatment area and the mud discharge area. A valve is installed at one end of the mud discharge pipe. The blockage drainage pipe is connected with the wetland treatment area and the mud discharge canal respectively. The mud discharge canal is connected with the mud storage tank. The mud discharge pipe is connected with the blockage dredging pipe. The treatment area and the anti-seepage layer are connected, and aquatic plants are planted on the surface of the wetland treatment area; the filling matrix in the water distribution area is pebbles, and the wetland treatment area is followed by mud drainage, anti-seepage layer, guide The water layer and the wetland treatment area, where aquatic plants are planted on the surface of the wetland treatment area. It alleviates the technical problem that the constructed wetland system is easy to block, prolongs its service life, and reduces its operating cost. The system is simple to operate, has high engineering practical value, and is convenient for popularization and application.

Description

A Constructed Wetland System Using Dredging Tubes to Prevent Blockage

technical field

The invention belongs to the technical field of constructed wetland sewage treatment, and in particular relates to an anti-clogging constructed wetland system. Specifically, the concept of "drainage" is proposed for the first time in the constructed wetland system. , by placing a blockage dredging pipe, it can discharge the blockage inside the wetland and have the effect of oxygenation, and at the same time, monitor the physical and chemical properties of the wetland water quality during the operation of the wetland.

Background technique

Constructed wetlands (CWs) is a sewage treatment process that emerged in the 1970s. By simulating the ecosystem of natural wetlands, the process utilizes the joint action of wetland matrix, plants and microorganisms to achieve the purpose of purifying sewage. According to the form of water flow, constructed wetlands can be roughly divided into surface flow constructed wetlands and subsurface flow constructed wetlands, while subsurface flow constructed wetlands can be further divided into horizontal subsurface flow and vertical subsurface flow constructed wetlands, and composite vertical flow constructed wetlands. It has been widely used at home and abroad because of its low investment, simple process, and low operating costs.

However, a large number of engineering practices have shown that with the increase of operating time of the constructed wetland, different degrees of blockage will occur inside it. The U.S. Environmental Protection Agency published a survey report on hundreds of constructed wetlands in 1999, showing that about half of the wetlands will experience various blockage problems within five years of operation; there are also many domestic researches on artificial wetlands. Wetland clogging phenomenon reports, such as my country's earliest constructed wetland sewage treatment system - Shenzhen Bainikeng Constructed Wetland has various clogging problems. Chinese patent document CN 207468300U discloses a method for discharging sludge and preventing clogging in a horizontal flow artificial wetland, that is, using the principle of sludge discharge in a V-shaped sedimentation tank in a sewage treatment plant, a V-shaped sludge collection tank is set in the wetland treatment area, and the sludge collection tank and The sludge discharge pipe is connected, and the sludge discharge pipe leads to the sludge discharge channel, and finally the blockage enters the sludge storage tank through the sludge discharge channel. The method in this patent does not consider the horizontal force of the water flow. Under the action of the water flow, the blockage cannot be smoothly deposited into the mud collection tank, so the blockage inside the wetland cannot be collected in time, and the wetland will still be blocked. Chinese patent Chinese patent document CN106430597A discloses an anti-clogging artificial wetland system, including a flushing system and a pollutant collection system, but the whole process requires an external power drainage pump, and can only clean the filter block in the water spray area, and cannot discharge bottom sewage. Mud failed to effectively solve the problem of wetland blockage. The invention provides a new method for alleviating blockage in constructed wetlands, which can more economically and effectively remove blockages inside the wetlands.

Contents of the invention

The purpose of the present invention is to provide an anti-clogging subsurface flow constructed wetland system, which can regularly discharge the sludge inside the wetland filler, increase the dissolved oxygen inside the wetland, alleviate the technical problem that the constructed wetland system is easy to clog, and prolong its life. service life, reducing its operating costs. The system is simple to operate, has high engineering practical value, and is convenient for popularization and application.

In order to achieve the above object, the present invention adopts the following technical solutions:

An anti-clogging constructed wetland system, comprising a water inlet pipe, a water distribution area, a wetland treatment area, an anti-seepage layer, a water collection area, a water outlet pipe, a mud discharge pipe, a mud discharge channel, a mud storage tank, and a blockage dredging pipe. The relationship is: the water inlet pipe is connected to the water distribution area, the wetland treatment area is connected to the water distribution area, the outlet pipe is connected to the water collection area, and the mud discharge pipe is connected to the wetland treatment area and the mud discharge channel respectively, and a valve is installed at one end of the mud discharge pipe , the blockage dredging pipe is connected with the wetland treatment area and the mud discharge channel respectively, the mud discharge channel is connected with the mud storage tank, the mud discharge pipe is connected with the blockage dredging pipe, and the aquifer is connected with the wetland treatment area and the anti-seepage layer respectively. Aquatic plants are planted on the surface of the area; the filling matrix in the water distribution area is pebbles with a particle size range of 30-50mm; while the filling matrix in the wetland treatment area is gravel with a particle size range of 4-8mm. From bottom to top, the wetland treatment area is followed by mud drain, anti-seepage layer, aquifer layer, wetland treatment area (core purification matrix layer), and aquatic plants are planted on the surface of the wetland treatment area. As a preferred technical solution of the present invention, the wetland system is a horizontal subsurface flow artificial wetland, and along the direction of water flow, there are water distribution area, wetland treatment area, and water collection area in sequence.

Using the above-mentioned anti-clogging artificial wetland system, a method for alleviating wetland clogging, the steps are:

A. The sewage enters the water distribution area 2 from the water inlet pipe 1, and then flows into the wetland treatment area 3. The sewage enters the water collection area 4 after purification treatment, and finally flows out of the wetland system through the outlet pipe 5;

B. Several blockage dredging pipes 6 are arranged in the wetland treatment area 3. During the operation of the wetland, the blockage between the substrates enters the pipe through the hole 11 on the upper part of the blocked dredging pipe under the impact of the water flow, and flows into the mud discharge pipe by its own gravity 7 in;

C. The mud discharge pipe 7 is provided with a certain slope. During the bed rest stage before each water intake, by opening the valve 12, the blockage flows into the mud discharge channel 8 along the slope. The sludge discharge channel is provided with a certain slope, and the blockage can be removed. It flows into the mud storage tank along the mud drain.

By using the blocked dredging pipe, the sludge inside the wetland filler can be regularly discharged, the dissolved oxygen inside the wetland can be increased, its service life can be extended, and its operating cost can be reduced. The system is simple to operate, has high engineering practical value, and is convenient for popularization and application.

As a preferred technical solution of the present invention, the filling matrix in the water distribution area is pebbles with a particle size range of 30-50mm; while the filling matrix in the wetland treatment area is gravel with a particle size range of 4-8mm.

As a preferred technical solution of the present invention, the end of the mud discharge pipe close to the mud discharge channel is provided with a control valve.

As a preferred technical solution of the present invention, the two wetland treatment area units can share one mud drain, or can use two mud drains separately.

As a preferred technical solution of the present invention, the wetland treatment area includes a mud drainage channel, an anti-seepage layer, a water-conducting layer, and a core purification matrix layer from bottom to top, and aquatic plants are planted on the surface of the core purification matrix layer.

As a preferred technical solution of the present invention, the construction of the anti-seepage layer and the water-conducting layer are all designed according to the design code of the constructed wetland.

As a preferred technical solution of the present invention, the diameters of the blockage dredging pipe and the mud discharge pipe in the wetland treatment area are both DN200-300mm.

As a preferred technical solution of the present invention, the blockage dredging pipe and the mud discharge pipe in the wetland treatment area can be connected through bends and tees.

As a preferred technical solution of the present invention, the blockage dredging pipe is provided with a certain height reserved section according to the height of the wetland filler, and the reserved section is connected with the mud discharge pipe, and its function is to store the blockage, while the remaining length of the dredged pipe is uniformly distributed with small holes , the pore size is slightly larger than the particle size of the matrix and the pore size on the upstream side is smaller than that on the back side and they are staggered with each other, so that it has the function of secondary water distribution; Its exterior is lined with a layer of 100-mesh nylon gauze or a custom-made sleeve of the same material.

As a preferred technical solution of the present invention, the mud discharge pipe is arranged along a direction perpendicular to the water flow, with a slope of 2% to 10%.

As a preferred technical solution of the present invention, the mud discharge channel is parallel to the water flow direction, and the slope is set at 2% to 10%.

As a preferred technical solution of the present invention, the number of blocked dredging pipes and mud discharge pipes is determined according to the scale and treatment capacity of the wetland.

This invention introduces the concept of "dredging" for the first time, and constructs a new type of anti-clogging constructed wetland system by adding a blocked dredging pipe. Compared with prior art, the beneficial effect of the present invention is:

(1) The present invention transforms the traditional constructed wetland by adding a blockage dredging pipe system. This system not only has the function of secondary water distribution, but also can regularly discharge the blockage inside the wetland to prolong the service life of the wetland;

(2) Wetland blockage dredging pipe can be used as the first choice for monitoring various physical and chemical parameters inside the wetland. The probe of the water quality tester can be directly inserted into the pipe, so as to conduct online monitoring of the physical and chemical properties inside the wetland, so as to take maintenance measures;

(3) Blocking the dredging pipe can play the role of oxygen circulation when the wetland is empty, increasing the dissolved oxygen at the bottom of the wetland, which is conducive to the growth of aerobic microorganisms at the bottom, thereby improving the COD removal efficiency of the wetland. According to the structure of the present invention, two small-scale horizontal subsurface flow artificial wetlands were constructed. Between May 10 and June 20, 2019, the dissolved oxygen at the bottom of the wetland was measured by inserting the probe of the YSL water quality online instrument into the blocked dredging pipe. , it was found that the dissolved oxygen at the bottom of the wetland was only 0.16-0.20mg/L during operation, and it was in a state of severe hypoxia. After the wetland was emptied, the air quickly entered the bottom of the wetland through the blocked dredging pipe, so that the dissolved oxygen returned to the atmospheric level. This will help the nitrification and denitrification reactions inside the wetland, and improve the denitrification rate of the wetland to a certain extent.

(4) The horizontal underflow constructed wetland system of the present invention is simpler to relieve blockage, has high engineering practical value, and is convenient for popularization and application.

Description of drawings

Fig. 1 is a kind of anti-clogging subsurface flow constructed wetland system plan layout;

Fig. 2 is a front sectional view of an anti-clogging subsurface flow constructed wetland system;

Fig. 3 is a left-side sectional view of an anti-clogging subsurface flow constructed wetland system;

Fig. 4 is a kind of schematic diagram of blockage dredging pipe structure;

Fig. 5 is a kind of structure schematic diagram of mud discharge pipe;

In the figure: 1-water inlet pipe, 2-water distribution area, 3-wetland treatment area, 4-water collection area, 5-outlet pipe, 6-blockage dredging pipe, 7-mud discharge pipe, 8-mud discharge channel, 9 - mud storage tank, 10 - wetland plants, 11 - hole, 12 - valve, 13 - anti-seepage layer, 14 - water guiding layer.

Detailed ways

Example 1:

The present invention will be described in further detail below in conjunction with embodiment.

According to Fig. 1, Fig. 2, Fig. 3 and Fig. 4, it can be seen that an anti-clogging subsurface flow constructed wetland system, the horizontal subsurface flow constructed wetland system includes: water inlet pipe 1, water distribution area 2, wetland treatment area 3, anti-seepage layer 13 , water collection area 4, and water outlet pipe 5, the connection relationship is: water inlet pipe 1 is connected to water distribution area 2, wetland treatment area 3 is connected to water distribution area 2, water outlet pipe 5 is connected to water collection area 4, and mud discharge pipe 7 They are respectively connected to the wetland treatment area 3 and the mud discharge channel 8, and a valve 12 is installed at one end of the sludge discharge pipe 7. The blockage dredging pipe 6 is respectively connected to the wetland treatment area 3 and the mud discharge channel 8. Connected, the mud discharge pipe 7 is connected with the blockage dredging pipe 6, the water-conducting layer 14 is connected with the wetland treatment area 3 and the anti-seepage layer 13 respectively, and aquatic plants 10 are planted on the surface of the wetland treatment area 3; the matrix is filled in the water distribution area 2 It is cobblestone with a particle size range of 30 or 35 or 41 or 46 or 50 mm; while the matrix filled in the wetland treatment area 3 is gravel with a particle size range of 4 or 6 or 8 mm. From bottom to top, the wetland treatment area includes mud drain 8, anti-seepage layer 13, aquifer 14, wetland treatment area 3 (core purification matrix layer), and aquatic plants 10 are planted on the surface of the wetland treatment area 3.

The sewage in the wetland treatment area 3 enters the water distribution area 2 from the water inlet pipe 1, and then flows into the wetland treatment area 3. The sewage enters the water collection area 4 after purification treatment, and finally flows out of the wetland system through the outlet pipe 5. Referring to Fig. 2 is a sectional view of a wetland unit in Fig. 1 in the direction of vertical water flow, referring to Fig. 3 is a sectional view of a wetland unit in Fig. 1 along the direction of water flow, in which several blockage dredging pipes 6 are arranged in the wetland treatment area 3 , the specific number is preferably 4-8 per square meter; during wetland operation, the blockage between the substrates enters the pipe through the hole 11 on the upper part of the blocking dredging pipe 6 under the impact of the water flow, and flows down into the mud discharge pipe In 7, the mud discharge pipe 7 is provided with a certain slope, and the slope range is 2% to 10%; in the bed rest stage before each water intake, by opening the valve 12, the blockage flows into the mud discharge channel 8 along the slope, and the discharge The slope of the mud ditch is set at 2% to 10%, and the blockage flows into the mud storage tank 9 along the mud ditch.

During the operation of the horizontal pushing flow constructed wetland of the present invention, the sludge discharge pipe valve 12 in the sludge discharge channel 8 is opened periodically, and the sludge inside the constructed wetland treatment area 3 is discharged to the sludge discharge channel 8 by using hydrostatic pressure, and finally discharged into the sludge storage tank 9 Medium; sludge can be used for subsequent resource utilization.

Referring to Fig. 1, in the present embodiment, the specific number of dredging pipes 6 in the horizontal subsurface flow constructed wetland is advisable to be 4-8 per square meter, but it can be flexibly designed according to the treatment scale and terrain in practical applications, so that Its construction costs are minimal.

Referring to Fig. 1 and Fig. 2, the construction of the anti-seepage layer 13 and the water-guiding layer 14 are designed according to the design code of the constructed wetland.

Referring to Fig. 4 and Fig. 5, the diameters of the blockage dredging pipe 6 and the mud discharge pipe 7 in the wetland treatment area 3 are both DN200-300mm.

Referring to Fig. 1 and Fig. 2, the blockage dredging pipe 6 and the mud discharge pipe 7 in the wetland treatment area 3 can be connected by bends and tees.

As an embodiment of the present invention, the blockage dredging pipe 6 is provided with a reserved section of a certain height according to the height of the wetland filler, and the reserved section is connected with the mud discharge pipe 7, and its function is to store blockages, while the remaining length of the dredged pipe is evenly distributed. Small holes are distributed, the pore diameter is slightly larger than the particle size of the matrix, and the pore diameter on the upstream surface is smaller than that on the backwater surface, and they are staggered from each other, so that they have the function of secondary water distribution; , lay a layer of 100-mesh nylon gauze on the outside or customize a pipe sleeve of the same material.

As an embodiment of the present invention, the mud discharge pipe 7 is arranged along a direction perpendicular to the water flow, with a slope of 2%-10%.

As an embodiment of the present invention, the mud discharge channel 8 is parallel to the water flow direction, and the slope is set at 2%-10%.

Through the above specific technical measures, the following technical problems and difficulties have been solved and the following effects have been achieved:

(1) In actual engineering, after a period of operation of constructed wetlands, different degrees of clogging will occur. The constructed wetland system can not only discharge the blockage inside the wetland regularly, but also has the function of secondary water distribution, which makes the water distribution more uniform, alleviates the problem of wetland blockage from the root, and prolongs the service life of the constructed wetland;

(2) The constructed wetland area in the actual project is large, and some physical and chemical parameters inside the wetland are not easy to monitor. The wetland blockage dredging tube can be used as the preferred point for monitoring various physical and chemical parameters inside the wetland. The probe of the water quality tester can be directly inserted into the tube, so as to monitor the physical and chemical properties inside the wetland online, so as to take maintenance measures in time;

(3) The hypoxia at the bottom of the constructed wetland in the actual project is serious. The blockage dredging pipe can play the role of oxygen flow when the wetland is empty, increasing the dissolved oxygen at the bottom of the wetland, which is beneficial to the growth of aerobic microorganisms at the bottom, thereby improving the COD removal efficiency of the wetland; Improve the denitrification rate of wetlands to a certain extent.

(4) The horizontal underflow constructed wetland system of the present invention is simpler to relieve blockage, has high engineering practical value, and is convenient for popularization and application.

Claims (7)

1. the utility model provides a prevent undercurrent constructed wetland system of jam, this constructed wetland system includes inlet tube (1), water distribution district (2), wetland treatment area (3), catchment area (4), outlet pipe (5), barrier layer (13), its characterized in that: the water inlet pipe (1) is connected with the water distribution area (2), the wetland treatment area (3) is connected with the water distribution area (2), the water outlet pipe (5) is connected with the water collection area (4), the sludge discharge pipe (7) is respectively connected with the wetland treatment area (3) and the sludge discharge channel (8), a valve (12) is arranged at one end of the sludge discharge pipe (7), the blocking dredging pipe (6) is respectively connected with the wetland treatment area (3) and the sludge discharge channel (8), the sludge discharge channel (8) is connected with the sludge storage pool (9), the sludge discharge pipe (7) is connected with the blocking dredging pipe (6), the water guide layer (14) is respectively connected with the wetland treatment area (3) and the impermeable layer (13), and aquatic plants (10) on the surface of the wetland treatment area (3).

2. The anti-clogging subsurface flow constructed wetland system of claim 1, wherein: the filling substrate in the water distribution area (2) is cobblestone, and the particle size range is 30-50 mm; the substrate filled in the wetland treatment area (3) is gravel with the grain diameter ranging from 4 mm to 8 mm.

3. The anti-clogging subsurface flow constructed wetland system of claim 1, wherein: the wetland treatment area is sequentially provided with a mud discharge channel (8), an impermeable layer (13), a water guide layer (14) and the wetland treatment area 3 from bottom to top.

4. the anti-clogging subsurface flow constructed wetland system of claim 1, wherein: the pipe diameters of the blocking dredging pipe and the mud discharging pipe in the wetland treatment area (3) are DN 200-300 mm.

5. The anti-clogging subsurface flow constructed wetland system of claim 1, wherein: the sludge discharge pipe (7) is arranged along the direction vertical to the water flow, and the gradient is 2-10%.

6. The anti-clogging subsurface flow constructed wetland system of claim 1, wherein: the mud discharge channel (8) is parallel to the water flow direction, and the gradient is set to be 2% -10%.

7. The anti-clogging subsurface flow constructed wetland system of claim 1, wherein: 4-8 dredging pipes (6) are arranged per square meter.