Composite circulating type constructed wetland tail water treatment system and method thereof

Abstract

The invention discloses a compound circulating type constructed wetland tail water treatment system and a method thereof, and belongs to the technical field of water treatment systems. The system comprises a vertical subsurface flow wetland, a horizontal subsurface flow wetland and a surface flow wetland which are sequentially connected in series, tail water firstly passes through a water distribution unit of the vertical subsurface flow wetland, passes through a first multi-layer filler from bottom to top, collects the tail water subjected to primary purification, and then enters a perforated pipe water distribution unit of the horizontal subsurface flow wetland; according to the invention, the three wetland systems are compounded, and are strengthened in the circulating plug-flow surface flow wetland, the function division is reasonable, the tail water firstly enters the vertical subsurface flow wetland and the horizontal subsurface flow wetland, various types of pollutants such as organic matters, nitrogen, phosphorus and the like are strengthened to be removed, and the tail water is discharged into the circulating plug-flow surface flow wetland. Subsequent water enters the surface flow wetland, the submerged plants at the water bottom and the emergent aquatic plants on the water surface act together, the purified water quality is enhanced, and the tail water purification effect is improved.

Description

Technical Field

[0001] The present invention relates to the technical field of water treatment systems, and more specifically to a composite circulating artificial wetland tailwater treatment system and method thereof. Background Art

[0002] In wetland systems, insoluble organic particles in sewage are mainly removed through the interception, filtration and sedimentation of substrates and plants, while soluble organic matter is mainly absorbed by microorganisms in wetlands and decomposed, removed or utilized through anaerobic and aerobic biological metabolism of microorganisms. The purification effect of artificial wetlands on organic pollutants is related to factors such as the type of system, substrate type, reoxygenation conditions, residence time, and influent water quality. A treatment method that uses aerobic microorganisms (including facultative microorganisms) to carry out biological metabolism in the presence of oxygen to degrade organic matter and make it stable and harmless. Microorganisms use organic pollutants in water as substrates for aerobic metabolism, and after a series of biochemical reactions, they release energy step by step, and finally stabilize as low-energy inorganic matter to achieve the requirements of harmlessness. The main removal pathways of nitrogen in artificial wetland systems include: assimilation and absorption storage by plants and microorganisms, adsorption by substrates, deposition of organic nitrogen, and the production and release of nitrogen gas formed by nitrification and denitrification pathways of microorganisms. The removal of phosphorus in wetland systems mainly relies on the combined action of the matrix, plants and microorganisms, and is achieved through a series of complex chemical, physical and biological processes. Among them, microorganisms such as polyphosphate bacteria mineralize and decompose organic phosphorus compounds and oxidize and reduce inorganic phosphorus compounds and change their solubility through enzymatic reactions. Wetland plants absorb and enrich phosphorus pollutants in sewage directly and transform them into plant bodies. At the same time, plants affect the growth environment of microorganisms through the oxygen transport of roots and stems, indirectly promoting the purification of phosphorus.

[0003] Plants in artificial wetlands can also deliver oxygen to water bodies and increase water activity. Wetland plants also play an important role in controlling water pollution and degrading harmful substances.

[0004] The artificial wetland treatment system has the characteristics of large buffer capacity, good treatment effect, simple process, low investment and low operating cost, which is very suitable for further purification of tailwater from sewage treatment plants. According to the flow mode of sewage, artificial wetlands can be divided into surface flow artificial wetlands, horizontal subsurface flow artificial wetlands and vertical subsurface flow artificial wetlands. However, traditional wetlands cannot enhance the removal of nitrogen and phosphorus and organic matter. Summary of the invention

[0005] 1. Technical problem to be solved by the invention

[0006] In view of the defects and shortcomings of the prior art, the present invention provides a composite circulating artificial wetland tailwater treatment system and method. The present invention combines three wetland systems and strengthens them in a circulating surface flow wetland. The functional zoning is reasonable. The tailwater first enters the vertical submerged flow wetland and the horizontal submerged flow wetland to strengthen the removal of various types of organic matter, nitrogen, phosphorus and other pollutants, and then enters the surface flow wetland. The submerged plants on the bottom of the water and the emergent plants on the surface of the water work together to strengthen the purification of water quality and improve the tailwater purification effect.

[0007] 2. Technical solution

[0008] In order to achieve the above object, the technical solution provided by the present invention is:

[0009] A composite circulating artificial wetland tailwater treatment system of the present invention comprises a vertical subsurface flow wetland, a horizontal subsurface flow wetland and a surface flow wetland, wherein the input end of the vertical subsurface flow wetland is provided with a water inlet pipe, the output end of the water inlet pipe is connected with a water distribution main pipe, the water distribution main pipe is laid at the bottom of the vertical subsurface flow wetland, the output end of the water distribution main pipe is connected with a water distribution perforated pipe, a first multi-layer filler is provided in the vertical subsurface flow wetland, a collecting pipe is provided at the output end of the vertical subsurface flow wetland, the output end of the collecting pipe is connected with a collecting channel, and the output end of the collecting channel is provided with a horizontal subsurface flow wetland;

[0010] The input end of the horizontal subsurface flow wetland is connected to the collection channel through a water distribution through-pipe, a second multi-layer filler is arranged in the horizontal subsurface flow wetland, the output end of the horizontal subsurface flow wetland is connected to the water collection channel through a perforated collection pipe, and an outlet pipe is arranged at the output end of the water collection channel, one end of which extends into the surface flow wetland;

[0011] Submerged plants are planted at the bottom of the surface flow wetland, flow pushers are arranged at intervals inside the surface flow wetland, and a tailwater discharge main pipe is arranged at the output end of the surface flow wetland.

[0012] Furthermore, the vertical subsurface flow wetland, horizontal subsurface flow wetland and surface flow wetland are all planted with surface emergent plants.

[0013] Furthermore, the output end of the perforated collecting pipe is provided with an adjustable water outlet.

[0014] Furthermore, the surface flow wetland is annular.

[0015] Furthermore, the vertical subsurface flow wetlands and horizontal subsurface flow wetlands can be arranged in multiple groups in parallel in the inner circle of the surface flow wetland.

[0016] Furthermore, the total thickness of the first multi-layer filler is 150 cm, and from bottom to top, the pebble layer with a particle size of 50-80 mm is 40 cm thick, the biomass filler layer with a particle size of 30-50 mm is 60 cm thick, the biomass filler layer with a particle size of 10-30 mm is 30 cm thick, and the flake stone layer with a particle size of 5-8 mm is 20 cm thick.

[0017] Furthermore, the total thickness of the second multi-layer filler is 140 cm, which includes, from bottom to top, a 40 cm thick gravel layer with a particle size of 20-40 mm, a 40 cm thick biomass filler layer with a particle size of 10-30 mm, a 40 cm thick zeolite layer with a particle size of 20-40 mm, and a 20 cm thick gravel layer with a particle size of 5-10 mm.

[0018] A method for treating tailwater of a composite circulating artificial wetland system, comprising the following steps:

[0019] Step 1: The tail water to be treated is input into the water distribution main pipe through the water inlet pipe arranged in front of the vertical submerged flow wetland, and then the water is evenly distributed through the water distribution perforated pipe. The water flows upward through the first multi-layer filler to the surface of the vertical submerged flow wetland, and then after the surface water surface emergent plants act on it, the tail water enters the collection channel through the collection pipe;

[0020] Step 2: The tail water in the collection channel is evenly distributed through the water distribution through-pipe into the horizontal subsurface flow wetland. The water flows horizontally through the second multi-layer filler. Under the joint action of the surface emergent plants, the water flows to the vicinity of the terminal water collection channel. The tail water is then collected by the perforated collection pipe and enters the water collection channel through the adjustable outlet. The tail water then enters the surface flow wetland through the outlet pipe.

[0021] Step 3: The tailwater entering the surface flow wetland of the circulation channel is pushed by the flow pusher, and the submerged plants on the bottom of the water and the emergent plants on the surface work together to finally be discharged into the designated water body through the tailwater discharge main.

[0022] 3. Beneficial effects

[0023] Compared with the prior art, the technical solution provided by the present invention has the following beneficial effects:

[0024] The vertical subsurface flow wetland, horizontal subsurface flow wetland and surface flow wetland of the present invention are connected in series in sequence. The tail water first passes through the water distribution unit of the vertical subsurface flow wetland, passes through the first multi-layer filler from bottom to top, collects the tail water after the initial purification, and then enters the perforated pipe water distribution unit of the horizontal subsurface flow wetland, flows horizontally through the second multi-layer filler, and the tail water after purification is discharged to the circulating plug flow type surface flow wetland. The tail water is further purified under the action of emergent water, submerged plants and aquatic animals in the surface flow wetland. The present invention compounds the three wetland systems and strengthens them in the circulating surface flow wetland to improve the tail water purification effect.

[0025] The composite circulating artificial wetland process of the present invention is short and the functional zoning is reasonable. The tail water first enters the vertical submerged flow wetland and the horizontal submerged flow wetland to strengthen the removal of various types of organic matter, nitrogen, phosphorus and other pollutants, and then enters the surface flow wetland. The submerged plants on the bottom of the water and the emergent plants on the water surface work together to strengthen the purification of water quality. The water surface is large, the plant community is rich, and the landscape creation effect is good. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 A top view of the present invention;

[0027] Figure 2 It is a cross-sectional view of the present invention.

[0028] In the figure: 1. Vertical subsurface flow wetland; 101. Water inlet pipe; 102. Water distribution main pipe; 103. Water distribution perforated pipe; 104. First multi-layer filler; 105. Collecting pipe; 106. Collecting channel; 2. Horizontal subsurface flow wetland; 201. Water distribution through-pipe; 202. Second multi-layer filler; 203. Perforated collecting pipe; 2031. Adjustable water outlet; 204. Water collection channel; 205. Outlet pipe; 3. Surface flow wetland; 301. Submerged plants; 302. Flow pusher; 303. Tailwater discharge main pipe; 4. Surface emergent plants. DETAILED DESCRIPTION

[0029] The present invention will be further described below in conjunction with the accompanying drawings and embodiments:

[0030] Example 1

[0031] from Figure 1-2 It can be seen that a composite circulating artificial wetland tailwater treatment system of the present embodiment includes a vertical subsurface flow wetland 1, a horizontal subsurface flow wetland 2 and a surface flow wetland 3, the input end of the vertical subsurface flow wetland 1 is provided with a water inlet pipe 101, the output end of the water inlet pipe 101 is connected to a water distribution main pipe 102, the water distribution main pipe 102 is laid at the bottom of the vertical subsurface flow wetland 1, the output end of the water distribution main pipe 102 is connected to a water distribution perforated pipe 103, a first multi-layer filler 104 is provided in the vertical subsurface flow wetland 1, the output end of the vertical subsurface flow wetland 1 is provided with a collecting pipe 105, the output end of the collecting pipe 105 is connected to a collecting channel 106, and the output end of the collecting channel 106 is provided with a horizontal subsurface flow wetland 2;

[0032] The input end of the horizontal submerged flow wetland 2 is connected to the collecting channel 106 through a water distribution through-tube 201, a second multi-layer filler 202 is arranged in the horizontal submerged flow wetland 2, and the output end of the horizontal submerged flow wetland 2 is connected to the water collecting channel 204 through a perforated collecting pipe 203, an adjustable water outlet 2031 is arranged at the output end of the perforated collecting pipe 203, and a water outlet pipe 205 is arranged at the output end of the water collecting channel 204, and one end of the water outlet pipe 205 extends into the surface flow wetland 3;

[0033] Submerged plants 301 are planted at the bottom of the surface flow wetland 3 , flow pushers 302 are arranged at intervals inside the surface flow wetland 3 , and a tailwater discharge main pipe 303 is arranged at the output end of the surface flow wetland 3 .

[0034] The vertical subsurface flow wetland 1, the horizontal subsurface flow wetland 2 and the surface flow wetland 3 are all planted with surface emergent plants 4.

[0035] The surface flow wetland 3 is in a ring shape, and multiple groups of vertical subsurface flow wetlands 1 and horizontal subsurface flow wetlands 2 can be arranged in parallel in the inner circle of the surface flow wetland 3 .

[0036] The total thickness of the first multi-layer filler 104 is 150 cm, which includes, from bottom to top, a 40 cm thick pebble layer with a particle size of 50-80 mm, a 60 cm thick biomass filler layer with a particle size of 30-50 mm, a 30 cm thick biomass filler layer with a particle size of 10-30 mm, and a 20 cm thick flake stone layer with a particle size of 5-8 mm.

[0037] The total thickness of the second multi-layer filler 202 is 140 cm, which includes, from bottom to top, a 40 cm thick gravel layer with a particle size of 20-40 mm, a 40 cm thick biomass filler layer with a particle size of 10-30 mm, a 40 cm thick zeolite layer with a particle size of 20-40 mm, and a 20 cm thick gravel layer with a particle size of 5-10 mm.

[0038] Example 2

[0039] from Figure 1-2 It can be seen that the method of a composite circulating artificial wetland tailwater treatment system in this embodiment comprises the following steps:

[0040] Step 1: The tail water to be treated is input into the water distribution main pipe 102 through the water inlet pipe 101 arranged in front of the vertical submerged flow wetland 1, and then the water is evenly distributed through the water distribution perforated pipe 103. The water flows upward through the first multi-layer filler 104 to the surface of the vertical submerged flow wetland 1, and then after the surface water surface emergent plants 4 act on the tail water, the tail water enters the collection channel 106 through the collection pipe 105;

[0041] Step 2: The tail water in the collection channel 106 is evenly distributed through the water distribution through-tube into the horizontal subsurface flow wetland 2, and the water flows horizontally through the second multi-layer filler 202. Under the joint action of the surface emergent plants 4, the water flows to the vicinity of the terminal water collection channel 204, and then the tail water is collected by the perforated collection pipe 203 and enters the water collection channel 204 through the adjustable outlet 2031, and then the tail water enters the surface flow wetland 3 through the outlet pipe 205;

[0042] Step 3: The tailwater entering the circulation channel surface flow wetland 3 is pushed by the flow pusher 302, the submerged plants 301 on the bottom of the water and the emergent plants 4 on the surface of the water work together, and is finally discharged to the designated water body through the tailwater discharge main 303.

[0043] In view of the shortcomings of the current single vertical flow or horizontal subsurface flow artificial wetland technology or surface flow wetland technology, the present invention provides a vertical subsurface flow + horizontal subsurface flow + circulating surface flow artificial wetland composite treatment system with strong nitrogen and phosphorus removal capabilities, high organic matter removal efficiency, and strong impact load resistance.

[0044] The vertical subsurface flow wetland 1, the horizontal subsurface flow wetland 2 and the surface flow wetland 3 are connected in series in sequence. The tail water first passes through the water distribution unit of the vertical subsurface flow wetland 1, passes through the first multi-layer filler 104 from bottom to top, collects the tail water after the initial purification, and then enters the perforated pipe water distribution unit of the horizontal subsurface flow wetland 2, flows horizontally through the second multi-layer filler 202, and the tail water after purification is discharged to the circulating plug flow surface flow wetland 3. The tail water is further purified in the surface flow wetland 3 under the action of emergent water, submerged plants and aquatic animals. The present invention combines the three wetland systems and strengthens them in the circulating surface flow wetland to improve the tail water purification effect.

[0045] The composite circulating artificial wetland process of the present invention is relatively short and has reasonable functional zoning. The tail water first enters the vertical submerged flow wetland 1 and the horizontal submerged flow wetland 2 to enhance the removal of various types of organic matter, nitrogen, phosphorus and other pollutants, and then enters the surface flow wetland 3. The submerged plants 301 at the bottom of the water and the emergent plants 4 on the water surface work together to enhance the purification of water quality. The water surface is large, the plant community is rich, and the landscape creation effect is good.

[0046] The present invention and its embodiments are described schematically above, and the description is not restrictive. The drawings show only one embodiment of the present invention, and the actual structure is not limited thereto. Therefore, if a person skilled in the art is inspired by it and designs a structural method and an embodiment similar to the technical solution without creativity without departing from the purpose of the invention, they shall all fall within the protection scope of the present invention.

Claims

1. A composite circulating artificial wetland tailwater treatment system, comprising a vertical subsurface flow wetland (1), a horizontal subsurface flow wetland (2) and a surface flow wetland (3), characterized in that: The vertical subsurface flow wetland (1) is provided with a water inlet pipe (101) at the input end, the water inlet pipe (101) is connected to a water distribution main pipe (102) at the output end, the water distribution main pipe (102) is laid at the bottom of the vertical subsurface flow wetland (1), the water distribution main pipe (102) is connected to a water distribution perforated pipe (103) at the output end, a first multi-layer filler (104) is provided in the vertical subsurface flow wetland (1), a collecting pipe (105) is provided at the output end of the vertical subsurface flow wetland (1), the collecting pipe (105) is connected to a collecting channel (106), and a horizontal subsurface flow wetland (2) is provided at the output end of the collecting channel (106); The input end of the horizontal subsurface flow wetland (2) is connected to the collection channel (106) via a water distribution through-tube (201), a second multi-layer filler (202) is arranged in the horizontal subsurface flow wetland (2), the output end of the horizontal subsurface flow wetland (2) is connected to the water collection channel (204) via a perforated collection pipe (203), the output end of the water collection channel (204) is provided with a water outlet pipe (205), and one end of the water outlet pipe (205) extends into the surface flow wetland (3); Submerged plants (301) are planted at the bottom of the surface flow wetland (3), flow pushers (302) are arranged at intervals inside the surface flow wetland (3), and a tailwater discharge main pipe (303) is arranged at the output end of the surface flow wetland (3).

2. A composite circulating artificial wetland tailwater treatment system according to claim 1, characterized in that: The vertical subsurface flow wetland (1), the horizontal subsurface flow wetland (2) and the surface flow wetland (3) are all planted with surface emergent plants (4).

3. A composite circulating artificial wetland tailwater treatment system according to claim 2, characterized in that: The output end of the perforated collecting pipe (203) is provided with an adjustable water outlet (2031).

4. A composite circulating artificial wetland tailwater treatment system according to claim 3, characterized in that: The surface flow wetland (3) is ring-shaped.

5. A composite circulating artificial wetland tailwater treatment system according to claim 4, characterized in that: The vertical subsurface flow wetland (1) and the horizontal subsurface flow wetland (2) can be arranged in multiple groups in parallel in the inner circle of the surface flow wetland (3).

6. The composite circulating artificial wetland tailwater treatment system according to claim 1, characterized in that: The total thickness of the first multi-layer filler (104) is 150 cm, and from bottom to top, the thickness of the pebble layer with a particle size of 50-80 mm is 40 cm, the thickness of the biomass filler layer with a particle size of 30-50 mm is 60 cm, the thickness of the biomass filler layer with a particle size of 10-30 mm is 30 cm, and the thickness of the flake stone layer with a particle size of 5-8 mm is 20 cm.

7. The composite circulating artificial wetland tailwater treatment system according to claim 1 is characterized by: The second multi-layer filler (202) has a total thickness of 140 cm, which includes, from bottom to top, a 40 cm thick gravel layer with a particle size of 20-40 mm, a 40 cm thick biomass filler layer with a particle size of 10-30 mm, a 40 cm thick zeolite layer with a particle size of 20-40 mm, and a 20 cm thick gravel layer with a particle size of 5-10 mm.

8. The method of a composite circulating artificial wetland tailwater treatment system according to claim 5, characterized in that: The steps are: Step 1: The tail water to be treated is input into the water distribution main pipe (102) through the water inlet pipe (101) arranged in front of the vertical submerged flow wetland (1), and then the water is evenly distributed through the water distribution perforated pipe (103). The water flows upward through the first multi-layer filler (104) to the surface of the vertical submerged flow wetland (1), and then after being acted on by the surface emergent plants (4), the tail water enters the collection channel (106) through the collection pipe (105); Step 2: The tail water in the collection channel (106) is evenly distributed through the water distribution through-tube and enters the horizontal subsurface flow wetland (2). The water flows horizontally through the second multi-layer filler (202). Under the joint action of the surface emergent plants (4), the water flows to the vicinity of the terminal water collection channel (204). The tail water is then collected through the perforated collection pipe (203) and enters the water collection channel (204) through the adjustable outlet (2031). The tail water then enters the surface flow wetland (3) through the outlet pipe (205); Step 3: The tailwater entering the circulation channel surface flow wetland (3) is pushed by the flow pusher (302), and the submerged plants (301) on the bottom of the water and the emergent plants (4) on the surface of the water work together to finally be discharged to the designated water body through the tailwater discharge main (303).

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