Bidirectional cross-flow subsurface wetland system

Abstract

The utility model discloses a bidirectional cross flow subsurface flow wetland system, which comprises a first water inlet system, a first water outlet system, a second water inlet system, a second water outlet system, a wetland system and a gate control system, the first water inlet system comprises a first water inlet valve, a first water inlet main pipe and an upper water distribution branch pipe; the second water inlet system comprises a second water inlet valve, a second water inlet main pipe and a lower water distribution branch pipe; the wetland system comprises emergent aquatic plants, a first filler layer, a second filler layer, a supporting layer, a partition wall, a wetland bed body and a bottom channel; according to the utility model, the interior of the wetland bed body is divided into a plurality of wetland units through the partition walls, and each wetland unit is switched to form an up-flow wetland unit and a down-flow wetland unit by switching on and off of the upper gate and the lower gate. Daily, frequent and automatic backwashing operation of the filler layer is realized, so that the blockage risk of the filler layer is reduced.

Description

Technical Field

[0001] The utility model belongs to the field of sewage treatment, and specifically relates to a bidirectional cross-flow submerged flow wetland system. Background Art

[0002] In recent years, subsurface artificial wetlands have been widely used in sewage treatment, especially in the treatment of micro-polluted water bodies, due to their high removal efficiency of ammonia nitrogen and organic matter, high stability and resistance to shock loads. Subsurface wetlands purify pollutants mainly through the fillers in the wetlands and the microorganisms growing on them. The fillers mainly intercept pollutants in sewage through physical filtration, and the microorganisms growing on them mainly remove pollutants through absorption and degradation.

[0003] With the operation of the wetland system, non-filterable substances such as organic and inorganic suspended solids in sewage, insoluble precipitates formed by reactions between some ions, etc. gradually accumulate in the pores of the filler and occupy the pores. In addition, a large number of microorganisms and their secreted extracellular polymers accumulate on the surface of the filler, which will form high-water-content, low-density colloidal silt with organic matter in the water body, causing the porosity of the wetland to decrease. Then the wetland will be blocked. When the wetland is blocked, the smooth flow and stability of the internal sewage will be destroyed and water will be stagnant, which will greatly reduce its decontamination effect and bring the risk of periodic exceeding of the effluent standard.

[0004] Regular flushing of fillers can reduce the frequency of wetland blockage, but flushing will inevitably affect the normal operation of the wetland. At the same time, the flushing operation is complicated and the overall cost is high. Regular replacement of fillers can also avoid wetland blockage to a certain extent, but the operation is large in engineering. At the same time, the wetland purification function is lost during the replacement of fillers, and the sewage discharge problem is difficult to solve. Utility Model Content

[0005] The purpose of the utility model is to provide a bidirectional cross-flow submerged flow wetland system in view of the above-mentioned problems existing in the prior art.

[0006] In order to solve the above technical problems, the technical solution adopted by the utility model is:

[0007] A two-way cross-flow submerged wetland system comprises a wetland bed, a supporting layer is arranged at the bottom of the wetland bed, a bottom channel is formed between the supporting layer and the bottom of the wetland bed, a packing layer is arranged on the supporting layer, two opposite sides of the wetland bed are respectively a water inlet side and a water outlet side, a first water inlet main pipe is arranged on the supporting layer and one end extends out of the water inlet side, a second water inlet main pipe is arranged at the bottom channel and one end extends out of the water inlet side, a second water outlet pipe connected to the upper part of the packing layer is arranged on the water outlet side, a first water outlet pipe connected to the bottom channel is also arranged on the water outlet side, the wetland bed is divided by a plurality of partition walls from the water inlet side to the water outlet side in sequence, the first water inlet main pipe runs through the upper part of each partition wall and an upper gate is arranged near each partition wall, the second water inlet main pipe runs through the lower part of each partition wall and a lower gate is arranged near each partition wall.

[0008] As mentioned above, the top of the partition wall extends out of the top surface of the filler layer, and the bottom of the partition wall is connected to the bottom of the wetland bed.

[0009] As described above, the first water inlet pipe is provided with a first water inlet valve at the end extending out of the water inlet side, the second water inlet pipe is provided with a second water inlet valve at the end extending out of the water inlet side, the first water outlet pipe is provided with a first water outlet valve, and the second water outlet pipe is provided with a second water outlet valve.

[0010] As mentioned above, emergent plants are arranged on the top surface of the packing layer.

[0011] As mentioned above, the emergent plant is a water lily or a reed.

[0012] As mentioned above, the supporting layer is a perforated steel plate.

[0013] As mentioned above, the packing layer includes a first packing layer and a second packing layer laid from top to bottom, the first packing layer is ceramsite with a particle size of 15-25 mm, the second packing layer is gravel with a particle size of 25-35 mm, and the thickness of the first packing layer is greater than that of the second packing layer.

[0014] Compared with the prior art, the utility model has the following beneficial effects:

[0015] The utility model divides the wetland bed into a plurality of wetland units by partition walls, and switches the upper gate on the first water inlet pipe and the lower gate on the second water inlet pipe to form an upflow wetland unit and a downflow wetland unit for each wetland unit. The wetland unit realizes daily, frequent and automatic backwashing of the packing layer by alternating upflow and downflow (bidirectional flow) operation, thereby reducing the risk of packing layer blockage. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 It is a structural schematic diagram of the utility model;

[0017] Wherein: 1-first water inlet system; 101-first water inlet valve; 102-first water inlet main pipe; 103-upper water distribution branch pipe;

[0018] 2-first water outlet system; 201-first water outlet valve; 202-first water outlet pipe;

[0019] 3-second water inlet system; 301-second water inlet valve; 302-second water inlet main pipe; 303-lower water distribution branch pipe;

[0020] 4-second water outlet system; 401-second water outlet valve; 402-second water outlet pipe;

[0021] 5-wetland system; 501-emergent plants; 502-first filler layer; 503-second filler layer; 504-support layer; 505-partition wall; 506-wetland bed; 507-bottom channel;

[0022] 6-gate control system; 601-first gate; 602-second gate; 603-third gate; 604-fourth gate; 605-fifth gate; 606-sixth gate. DETAILED DESCRIPTION

[0023] In order to facilitate those skilled in the art to understand and use the present invention, the present invention is further described in detail below in conjunction with embodiments. It should be understood that the implementation examples described herein are only used to illustrate and explain the present invention and are not used to limit the present invention.

[0024] Embodiment 1:

[0025] A bidirectional cross-flow submerged wetland system comprises a first water inlet system 1, a first water outlet system 2, a second water inlet system 3, a second water outlet system 4, a wetland system 5, and a gate control system 6;

[0026] The first water inlet system 1 includes a first water inlet valve 101, a first water inlet main pipe 102, and an upper water distribution branch pipe 103;

[0027] The first water outlet system 2 includes a first water outlet valve 201 and a first water outlet pipe 202;

[0028] The second water inlet system 3 includes a second water inlet valve 301, a second water inlet main pipe 302, and a lower water distribution branch pipe 303;

[0029] The second water outlet system 4 includes a second water outlet valve 401 and a second water outlet pipe 402;

[0030] The wetland system 5 includes emergent plants 501, a first filler layer 502, a second filler layer 503, a supporting layer 504, a partition wall 505, a wetland bed 506, and a bottom channel 507;

[0031] The gate control system 6 includes a first gate 601 , a second gate 602 , a third gate 603 , a fourth gate 604 , a fifth gate 605 , and a sixth gate 606 .

[0032] A supporting layer 504 is provided at the bottom of the wetland bed, and a bottom channel 507 is formed between the supporting layer 504 and the bottom of the wetland bed 506. The supporting layer 504 is a perforated steel plate, and a filler layer is provided on the supporting layer 504. In the vertical direction, the bottom channel 507 and the filler layer are interconnected, and the two opposite sides of the wetland bed 506 are respectively the water inlet side and the water outlet side.

[0033] like Figure 1 In the embodiment, the left side of the wetland bed 506 is the water inlet side, and the right side is the water outlet side. A first water inlet main pipe 102 is arranged on the supporting layer 504, and one end thereof extends out of the water inlet side. A first water inlet valve 101 is arranged at the end of the first water inlet main pipe 102 extending out of the water inlet side. The flow rate and water volume entering the first water inlet main pipe 102 are adjusted by the first water inlet valve 101. A plurality of upper water distribution branches 103 are arranged in sequence along the first water inlet main pipe 102. Water distribution holes are arranged on the first water inlet main pipe 102 and the upper water distribution branches 103. Preferably, each upper water distribution branch pipe 103 has a plurality of upper water distribution branches 103. Perpendicular to the first water inlet main pipe 102, the bottom channel 507 is provided with a second water inlet main pipe 302 and one end extends out of the water inlet side. The end of the second water inlet main pipe 302 extending out of the water inlet side is provided with a second water inlet valve 301. The flow rate and water volume of the second water inlet main pipe 302 are adjusted by the second water inlet valve 101. A plurality of lower water distribution branches 303 are provided along the second water inlet main pipe 302. Water distribution holes are provided on the second water inlet main pipe 302 and the lower water distribution branches 303. Preferably, each lower water distribution branch pipe 303 is provided perpendicular to the second water inlet main pipe 302.

[0034] A second water outlet pipe 402 connected to the upper part of the packing layer is provided on the water outlet side, and a second water outlet valve 401 is provided on the second water outlet pipe 402. A first water outlet pipe 202 connected to the bottom channel 507 is also provided on the water outlet side, and a first water outlet valve 201 is provided on the first water outlet pipe 202. The wetland bed 506 is divided by multiple partition walls 505 from the water inlet side to the water outlet side in sequence. The partition walls 505 are solid wall panels with a certain strength. The top of the partition walls 505 extends out of the top surface of the packing layer, and the bottom of the partition walls 505 is connected to the bottom of the wetland bed 506. Each partition wall 505 divides the wetland bed 506 from the water inlet side to the water outlet side into multiple wetland units. The first water inlet main pipe 102 runs through the upper part of each partition wall 505 and an upper gate is provided near each partition wall 505. The second water inlet main pipe 302 runs through the lower part of each partition wall 505 and a lower gate is provided near each partition wall 505.

[0035] Only one of the upper gate and the lower gate at the corresponding position of the partition wall 505 is opened, the upper gates at the corresponding positions of each partition wall 505 are opened at intervals, and the lower gates at the corresponding positions of each partition wall 505 are opened at intervals.

[0036] like Figure 1 As shown, in this embodiment, from the water inlet side to the water outlet side, the partition walls 505 are respectively the first partition wall, the second partition wall and the third partition wall, and the wetland units are respectively the first wetland unit, the second wetland unit, the third wetland unit and the fourth wetland unit.

[0037] In the first operating state, the upper gates (first gate 601 and fifth gate 605) near the first partition wall and the third partition wall are opened, and the lower gate (third gate 603) near the second partition wall is opened; the lower gates (second gate 602 and sixth gate 606) near the first partition wall and the third partition wall are closed, and the upper gate (fourth gate 604) near the second partition wall is closed; the second inlet valve 301 is opened, and the first inlet valve 101 is closed; the first outlet valve 201 is opened, and the second outlet valve 401 is closed. The first wetland unit is an upflow wetland unit, the second wetland unit is a downflow wetland unit, the third wetland unit is an upflow wetland unit, and the fourth wetland unit is a downflow wetland unit.

[0038] In the second operating state, the lower gates (second gate 602 and sixth gate 606) near the first partition wall and the third partition wall are opened, and the upper gate (fourth gate 604) near the second partition wall is opened; the upper gates near the first partition wall and the third partition wall are closed (first gate 601 and fifth gate 605), and the lower gate (third gate 603) near the second partition wall is closed; the second inlet valve 301 is closed, and the first inlet valve 101 is opened; the second outlet valve 201 is closed, and the second outlet valve 401 is opened. The first wetland unit is a downstream wetland unit, the second wetland unit is an upstream wetland unit, the third wetland unit is a downstream wetland unit, and the fourth wetland unit is an upstream wetland unit.

[0039] By switching the upper gate and the lower gate, the upflow and downflow switching of each wetland unit can be realized, and the daily, frequent and automatic backwashing operation of the packing layer can be realized, thereby reducing the risk of clogging of the packing layer.

[0040] The packing layer includes a first packing layer 502 and a second packing layer 503 laid from top to bottom. The packing of the first packing layer 502 and the second packing layer 503 is ceramsite, crushed stone or pebbles. An emergent plant 501 is arranged on the top surface of the second packing layer 503. The emergent plant 501 is a water lily or reed with strong tolerance and high oxygen transport capacity.

[0041] Embodiment 2:

[0042] Based on Example 1, the wetland bed is 4m long, 1m wide, 0.9m high, and has an effective water depth of 0.6m. The first filler layer is 0.4m thick, and the filler is ceramsite with a particle size of 15-25mm; the second filler layer is 0.2m thick, and the filler is gravel with a particle size of 25-35mm. A partition wall 505 is set every 1m in the wetland bed, and the partition wall 505 is a dense steel plate, including a first partition wall, a second partition wall, and a third partition wall.

[0043] The emergent plant is the plant of the genus Zephyranthes.

[0044] The supporting layer 504 is a water-permeable steel plate, on which mesh holes with a diameter of 5 mm are opened, and the opening rate of the water-permeable steel plate is 70%.

[0045] With 15 days as a cycle, the first operating state and the second operating state are switched alternately. During the two and a half years of stable operation of this embodiment, no plugging of the filler occurred. At the same time, the filler was taken out for observation and it was found that no insoluble sediments, microorganisms and their secreted extracellular polymers and other materials that reduce the porosity of the filler were found on the filler. Therefore, the utility model can effectively avoid the problem of filler plugging during the operation of the wetland.

[0046] The specific embodiments described herein are merely examples of the spirit of the present invention. Those skilled in the art may make various modifications or additions to the specific embodiments described or replace them in similar ways, but they will not deviate from the spirit of the present invention or exceed the scope defined by the appended claims.

Claims

1. A bidirectional cross-flow subsurface wetland system, comprising a wetland bed (506), characterized in that: A supporting layer (504) is provided at the bottom of the wetland bed body, a bottom channel (507) is formed between the supporting layer (504) and the bottom of the wetland bed body (506), a packing layer is provided on the supporting layer (504), two opposite sides of the wetland bed body (506) are respectively a water inlet side and a water outlet side, a first water inlet main pipe (102) is provided on the supporting layer (504) and one end extends out of the water inlet side, a second water inlet main pipe (302) is provided on the bottom channel (507) and one end extends out of the water inlet side, and a packing layer connected to the packing layer is provided on the water outlet side. The second water outlet pipe (402) is connected to the water inlet side, and the first water outlet pipe (202) connected to the bottom channel (507) is also provided on the water outlet side. The wetland bed (506) is divided by a plurality of partition walls (505) from the water inlet side to the water outlet side in sequence. The first water inlet main pipe (102) passes through the upper part of each partition wall (505) and an upper gate is provided near each partition wall (505). The second water inlet main pipe (302) passes through the lower part of each partition wall (505) and a lower gate is provided near each partition wall (505).

2. A bidirectional cross-flow submerged wetland system according to claim 1, characterized in that: The top of the partition wall (505) extends out of the top surface of the filler layer, and the bottom of the partition wall (505) is connected to the bottom of the wetland bed (506).

3. A bidirectional cross-flow submerged wetland system according to claim 2, characterized in that: A first water inlet valve (101) is provided at the end of the first water inlet main pipe (102) extending out of the water inlet side, a second water inlet valve (301) is provided at the end of the second water inlet main pipe (302) extending out of the water inlet side, a first water outlet valve (201) is provided on the first water outlet pipe (202), and a second water outlet valve (401) is provided on the second water outlet pipe (402).

4. A bidirectional cross-flow submerged wetland system according to claim 3, characterized in that: Emergent plants (501) are arranged on the top surface of the packing layer.

5. A bidirectional cross-flow submerged wetland system according to claim 4, characterized in that: The emergent plant (501) is a water lily or a reed.

6. A bidirectional cross-flow submerged wetland system according to claim 4, characterized in that: The supporting layer (504) is a perforated steel plate.

7. A bidirectional cross-flow submerged wetland system according to claim 4, characterized in that: The packing layer comprises a first packing layer (502) and a second packing layer (503) laid from top to bottom, the first packing layer (502) is ceramsite with a particle size of 15-25 mm, the second packing layer (503) is gravel with a particle size of 25-35 mm, and the thickness of the first packing layer (502) is greater than that of the second packing layer (503).

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