Unpowered composite subsurface flow constructed wetland capable of effectively removing pollutants

Abstract

The utility model relates to an unpowered composite subsurface flow constructed wetland capable of effectively removing pollutants, which is characterized in that a slow-release carbon source is arranged in a water distribution channel, a water outlet of the water distribution channel is communicated with a water distribution main pipe of an upstream subsurface flow constructed wetland through a water inlet pipe, and a plurality of water distribution main pipes are arranged on a downstream subsurface flow constructed wetland; sewage in the upstream subsurface flow constructed wetland flows into a water distribution main canal on the downstream subsurface flow constructed wetland through a water collection main pipe, and water distribution branch pipes are arranged on the two sides of the water distribution main canal in a crossed mode. The device has the beneficial effects that by adopting the organic combination of the upstream subsurface flow constructed wetland and the downstream subsurface flow constructed wetland, the composite reaction process of anoxic treatment and aerobic treatment is realized, and a carbon source is supplied before sewage enters an anoxic stage, so that denitrifying bacteria can fully utilize the carbon source to perform denitrification reaction in the anoxic stage, and the denitrification efficiency is improved. Phosphorus-accumulating bacteria absorb energy in the anoxic and anaerobic stages, so that phosphorus pollution is better reduced in the aerobic stage, and organic pollutants and ammonia nitrogen are more effectively removed in the aerobic stage.

Description

Technical Field

[0001] The utility model relates to the technical field of sewage treatment, in particular to a non-powered composite subsurface flow artificial wetland which can effectively remove pollutants. Background Art

[0002] In recent years, artificial wetlands have played an increasingly important role in sewage treatment plant tailwater treatment, reclaimed water reuse, and rural domestic sewage treatment due to their good pollutant removal effects, ecological properties, and low construction and operation costs. Artificial wetlands are divided into surface flow artificial wetlands and subsurface flow artificial wetlands. Among them, subsurface flow artificial wetlands are widely used because of their good pollutant removal effect and small footprint. Subsurface flow artificial wetlands are divided into horizontal subsurface flow artificial wetlands, downward subsurface flow artificial wetlands, and upward subsurface flow artificial wetlands according to the direction of water flow. Due to their good oxygen enrichment effect and anti-clogging effect, downward subsurface flow artificial wetlands have received continuous attention in recent years. However, the downward subsurface flow artificial wetlands lack the anoxic environment required for denitrification, and the problem of low carbon-nitrogen ratio of wetland influent leads to the inability of downward subsurface flow artificial wetlands to efficiently play the role of pollutant removal. As the matrix of the upward subsurface flow artificial wetland has been in a flooded environment, the wetland has a good anoxic environment, which is conducive to denitrification by denitrifying bacteria. As a solid carbon source, the slow-release carbon source can continuously provide carbon source for the wetland to make up for the low denitrification efficiency caused by the low carbon-nitrogen ratio of the wetland influent. At the same time, it can provide energy and electron donors for other microorganisms to promote biochemical reactions. Utility Model Content

[0003] The technical problem to be solved by the utility model is to provide a non-powered composite subsurface flow artificial wetland which can effectively remove pollutants, so as to overcome the deficiencies in the above-mentioned prior art.

[0004] The technical solution of the utility model for solving the above-mentioned technical problems is as follows: a non-powered composite subsurface flow artificial wetland that can effectively remove pollutants, comprising: a water distribution channel, a slow-release carbon source is arranged in the water distribution channel, the water outlet of the water distribution channel is connected with the water distribution main pipe of the ascending subsurface flow artificial wetland through an inlet pipe, a descending subsurface flow artificial wetland is arranged on the water outlet side of the ascending subsurface flow artificial wetland, a plurality of water distribution main channels are arranged on the descending subsurface flow artificial wetland, the sewage in the ascending subsurface flow artificial wetland flows into the water distribution main channel on the descending subsurface flow artificial wetland through a water collection main pipe, and water distribution branches are arranged on both sides of the water distribution main channel.

[0005] The beneficial effects of the utility model are:

[0006] 1) Let the sewage enter the water distribution channel with slow-release carbon source first, so that the sewage is mixed with the slow-release carbon source before being sent to the upward subsurface flow artificial wetland, which can effectively improve the carbon-nitrogen ratio of the wetland;

[0007] 2) The organic combination of the ascending subsurface flow constructed wetland and the descending subsurface flow constructed wetland is adopted to realize the composite reaction process of anoxic first and aerobic later, and the carbon source is replenished before the sewage enters the anoxic stage, so that the denitrifying bacteria can fully utilize the carbon source for denitrification reaction in the anoxic stage, and the polyphosphate bacteria absorb energy in the anoxic anaerobic stage, so as to better reduce phosphorus pollution in the aerobic stage, and more effectively remove organic pollutants and ammonia nitrogen in the aerobic stage, and effectively improve the removal rate of pollutants by the composite subsurface flow constructed wetland;

[0008] 3) It can realize non-powered operation, which reduces the operation cost and difficulty of operation and maintenance, improves the removal rate of pollutants, and is environmentally friendly.

[0009] On the basis of the above technical solution, the present invention can also be improved as follows.

[0010] Furthermore, the water distribution channel has a mixing zone, a mixing zone and a water distribution zone which are connected in sequence along the water flow direction, a slow-release carbon source is arranged in the mixing zone, and the outlet of the water distribution zone is connected to the water distribution main pipe of the ascending submerged flow artificial wetland through an inlet pipe.

[0011] A further beneficial effect of the above is that the water distribution channel of this structure can mix the sewage and the slow-release carbon source evenly.

[0012] Furthermore, partitions are arranged in the water distribution channel along the water flow direction, and hollow baffles are arranged in the water distribution channel at the tail end of the partitions along the water flow direction. The inner cavity of the water distribution channel is divided into a mixing zone, a mixing zone and a water distribution zone by the partitions and the hollow baffles. The mixing zone is connected with the mixing zone through the holes on the hollow baffles, and the mixing zone is connected with the water distribution zone through the holes on the hollow baffles.

[0013] Furthermore, the highest point of the water distribution main channel is lower than the lowest point of the water collection main pipe in the ascending subsurface flow artificial wetland.

[0014] The above-mentioned further beneficial effect is as follows: since there is a height difference between the water collection main pipe and the water distribution main channel, the sewage from the ascending submerged flow artificial wetland will flow into the water distribution main channel of the descending submerged flow artificial wetland in a falling manner. In this process, the waterfall oxygenation process from the ascending submerged flow artificial wetland to the descending submerged flow artificial wetland is realized, and it has a certain landscape beautification effect, and is connected with the atmosphere, so that the sewage entering the descending submerged flow artificial wetland has more dissolved oxygen.

[0015] Furthermore, the water distribution branch pipes on both sides of the water distribution main channel are cross-distributed, and the lowest point of the water distribution branch pipe is 10cm to 15cm away from the bottom of the water distribution main channel.

[0016] The above further beneficial effect is that the water distribution branch pipe is arranged at a certain height from the bottom of the water distribution main channel. After the water flow is evenly mixed in the water distribution main channel, it flows into the downward submerged flow artificial wetland through the water distribution branch pipe, thereby enhancing the uniformity of water distribution.

[0017] Furthermore, the uppermost end of the water distribution main channel is 10 cm to 15 cm higher than the planting soil layer of the downward subsurface flow artificial wetland.

[0018] A further beneficial effect of adopting the above method is that solid matter can be prevented from entering the water distribution main channel and blocking the downward submerged flow artificial wetland.

[0019] Furthermore, a hollow grate is installed on the water distribution main channel, and a dense wire mesh is fixed under the hollow grate.

[0020] A further beneficial effect of the above is that the structure formed by the hollow grate and the dense wire mesh allows air to enter, but prevents other solid matter from entering the water distribution canal, thereby preventing pollutants from entering the water distribution canal and blocking the downward subsurface flow artificial wetland.

[0021] Furthermore, the thickness of the filler layer of the ascending submerged flow artificial wetland is 60 cm to 80 cm, and the thickness of the filler layer of the descending submerged flow artificial wetland is 30 cm to 50 cm.

[0022] The above further beneficial effects are: an ascending submerged flow artificial wetland with a filler layer of this thickness facilitates the full carrying out of anoxic biochemical reactions, while a descending submerged flow artificial wetland with a filler layer of this thickness facilitates atmospheric oxygen enrichment, placing the entire filler layer in an aerobic environment.

[0023] Furthermore, a microbial migration slow-release layer is arranged below the water distribution layer of the ascending submerged flow artificial wetland and below the water collection layer of the descending submerged flow artificial wetland, and the microbial migration slow-release layer has microorganisms and a slow-release carbon source.

[0024] The above further beneficial effects are: the microbial migration slow-release layer, on the one hand, acts as a bio-affinity material, providing a good growth and reproduction carrier for microorganisms; on the other hand, it continuously and slowly releases carbon sources, providing energy and electron donors for microbial biochemical reactions in a targeted manner, thereby strengthening biochemical reactions.

[0025] Furthermore, the microorganisms added into the microbial migration slow-release layer below the ascending submerged flow artificial wetland are anaerobic and anoxic bacteria, and the microorganisms added into the microbial migration slow-release layer below the descending submerged flow artificial wetland are aerobic bacteria. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 It is a top view of the non-powered composite subsurface flow artificial wetland in the utility model that can effectively remove pollutants;

[0027] Figure 2 It is a front view of the non-powered composite subsurface flow artificial wetland in the utility model which can effectively remove pollutants.

[0028] In the accompanying drawings, the components represented by the reference numerals are listed as follows:

[0029] 1. Water distribution channel, 110. Mixing zone, 120. Mixing zone, 130. Water distribution zone, 2. Water inlet pipe, 3. Upward subsurface flow artificial wetland, 310. Water distribution main pipe, 320. Water collection main pipe, 4. Downward subsurface flow artificial wetland, 410. Water distribution main channel, 411. Water distribution branch pipe, 420. Hollow grate, 5. Microbial migration slow-release layer. DETAILED DESCRIPTION

[0030] The principles and features of the present invention are described below in conjunction with the accompanying drawings. The examples given are only used to explain the present invention and are not used to limit the scope of the present invention.

[0031] Example 1

[0032] like Figure 1 , Figure 2 As shown, a non-powered composite subsurface artificial wetland that can effectively remove pollutants comprises: a water distribution channel 1, a slow-release carbon source is arranged in the water distribution channel 1, the water outlet of the water distribution channel 1 is connected to the water distribution main pipe 310 of the ascending subsurface artificial wetland 3 through the water inlet pipe 2, in addition, a descending subsurface artificial wetland 4 is arranged on the water outlet side of the ascending subsurface artificial wetland 3, a plurality of water distribution main channels 410 are arranged on the descending subsurface artificial wetland 4, sewage in the ascending subsurface artificial wetland 3 flows into the water distribution main channel 410 on the descending subsurface artificial wetland 4 through the water collecting main pipe 320, and water distribution branch pipes 411 are arranged on both sides of the water distribution main channel 410;

[0033] The workflow is as follows:

[0034] The sewage to be treated is first introduced into the water distribution channel 1, and the sewage will be mixed with the slow-release carbon source in the water distribution channel 1. The sewage mixed with the slow-release carbon source will flow into the water distribution main pipe 310 of the ascending submerged flow artificial wetland 3 through the water inlet pipe 2, and after the pollutants are removed by the ascending submerged flow artificial wetland 3, it will flow into the water distribution main pipe 410 on the descending submerged flow artificial wetland 4 through the water collection main pipe 320, and the water will be evenly distributed to the downward submerged flow artificial wetland 4 by the water distribution branch pipe 411 on the water distribution main channel 410.

[0035] The slow-release carbon source in the utility model is formed by mixing and melting agricultural waste and high-density polymer, the agricultural waste is one or more of corn cobs, peanut shells, straws, and rice husks, and the high-density polymer is one or more of PVA, PBS, PLA, and PHBV. This type of slow-release carbon source has the advantages of good carbon release effect, stable carbon release rate, etc., and can continuously provide carbon source for sewage.

[0036] Example 2

[0037] like Figure 1 , Figure 2As shown, this embodiment is a further improvement on the basis of embodiment 1, and the details are as follows:

[0038] The water distribution channel 1 has a mixing zone 110, a mixing zone 120 and a water distribution zone 130 connected in sequence along the water flow direction. A slow-release carbon source is arranged in the mixing zone 110. The outlet of the water distribution zone 130 is connected to the water distribution main pipe 310 of the upward submerged flow artificial wetland 3 through the water inlet pipe 2. The sewage to be treated is first introduced into the mixing zone 110 of the water distribution channel 1. The sewage will be mixed with the slow-release carbon source in the mixing zone 110, and then the sewage mixed with the slow-release carbon source enters the mixing zone 120. After the water flow direction of the sewage is reversed in the mixing zone 120, it flows to the water distribution zone 130. Finally, the sewage evenly mixed with the slow-release carbon source in the water distribution zone 130 flows into the water distribution main pipe 310 of the upward submerged flow artificial wetland 3 through the water inlet pipe 2. The water distribution channel 1 with this structure can mix the sewage and the slow-release carbon source evenly.

[0039] As a further optimization of the above technical solution:

[0040] Partitions are arranged along the water flow direction in the water distribution channel 1, and hollow baffles are arranged at the tail ends of the partitions along the water flow direction in the water distribution channel 1. The inner cavity of the water distribution channel 1 is divided into a mixing zone 110, a mixing zone 120 and a water distribution zone 130 by the partitions and the hollow baffles. The mixing zone 110 is connected with the mixing zone 120 through the holes on the hollow baffles, and the mixing zone 120 is connected with the water distribution zone 130 through the holes on the hollow baffles. The sewage first enters the mixing zone 110 to mix with the slow-release carbon source, and then flows into the mixing zone 120 through the holes on the hollow baffles, and then the water flow direction is reversed after passing through the mixing zone 120 and flows from the holes on the hollow baffles to the water distribution zone 130.

[0041] Example 3

[0042] like Figure 2 As shown, this embodiment is a further improvement on the basis of Embodiment 1 or 2, and the details are as follows:

[0043] The highest point of the water distribution main channel 410 is lower than the lowest point of the water collection main pipe 320 in the ascending submerged flow artificial wetland 3. Since there is a height difference between the water collection main pipe 320 and the water distribution main channel 410, the sewage of the ascending submerged flow artificial wetland 3 will fall into the water distribution main channel 410 of the descending submerged flow artificial wetland 4. In this process, the waterfall oxygenation process from the ascending submerged flow artificial wetland 3 to the descending submerged flow artificial wetland 4 is realized, and it has a certain landscape beautification effect. It is connected with the atmosphere, so that the sewage entering the descending submerged flow artificial wetland 4 contains more dissolved oxygen.

[0044] Example 4

[0045] like Figure 2 As shown, this embodiment is a further improvement on any one of Embodiments 1 to 3, and the details are as follows:

[0046] The water distribution branches 411 on both sides of the water distribution main channel 410 are cross-distributed. In addition, the lowest point of the water distribution branch pipes 411 is 10 cm to 15 cm away from the bottom of the water distribution main channel 410, so that the water distribution of the entire downward submerged flow artificial wetland 4 is more uniform.

[0047] Example 5

[0048] like Figure 2 As shown, this embodiment is a further improvement on any one of Embodiments 1 to 4, and the details are as follows:

[0049] The top of the water distribution main channel 410 is 10 cm to 15 cm higher than the planting soil layer of the downward submerged flow artificial wetland 4 , which can prevent solid matter from entering the water distribution main channel 410 and clogging the downward submerged flow artificial wetland 4 .

[0050] Example 6

[0051] like Figure 1 As shown, this embodiment is a further improvement on any one of Embodiments 1 to 5, and the details are as follows:

[0052] A hollow grate 420 is installed on the water distribution main channel 410, and a dense wire mesh is fixed under the hollow grate 420. The material of the hollow grate 420 can be plastic. The structure formed by the hollow grate 420 and the dense wire mesh can allow air to enter, but will prevent other solid substances from entering the water distribution main channel 410, so as to prevent pollutants from entering the water distribution main channel 410 and blocking the downward subsurface flow artificial wetland.

[0053] Example 7

[0054] like Figure 2 As shown, this embodiment is a further improvement on any one of Embodiments 1 to 6, and the details are as follows:

[0055] The packing layer thickness of the upward submerged flow artificial wetland 3 is 60cm-80cm, which is convenient for the full anaerobic biochemical reaction, while the packing layer thickness of the downward submerged flow artificial wetland 4 is 30cm-50cm, which is convenient for atmospheric oxygen enrichment, so that the entire packing layer is in an aerobic environment.

[0056] Example 8

[0057] like Figure 2 As shown, this embodiment is a further improvement on any one of Embodiments 1 to 7, and the details are as follows:

[0058] The ascending submerged flow artificial wetland 3 arranges a microbial migration slow-release layer 5 below the water distribution layer, and the descending submerged flow artificial wetland 4 arranges a microbial migration slow-release layer 5 below the water collection layer. The microbial migration slow-release layer 5 is a mixture of microorganisms, slow-release carbon sources and fine sand. Among them, the microorganisms added to the microbial migration slow-release layer 5 below the ascending submerged flow artificial wetland 3 are mainly anaerobic and anoxic bacteria, while the microorganisms added to the microbial migration slow-release layer 5 below the descending submerged flow artificial wetland 4 are mainly aerobic bacteria. The slow-release carbon source of the microbial migration slow-release layer 5 can further provide energy to the microorganisms in a directionally slow manner, and serve as a bio-friendly carrier for the microorganisms to enhance the biochemical reaction.

[0059] Although the embodiments of the present invention have been shown and described above, it can be understood that the above embodiments are exemplary and cannot be understood as limitations of the present invention. Ordinary technicians in the field can change, modify, replace and modify the above embodiments within the scope of the present invention.

Claims

1. A non-powered composite subsurface artificial wetland that can effectively remove pollutants, characterized in that: include: A water distribution channel (1) is provided in which a slow-release carbon source is arranged; the water outlet of the water distribution channel (1) is connected to a water distribution main pipe (310) of an ascending submerged flow artificial wetland (3) via a water inlet pipe (2); a descending submerged flow artificial wetland (4) is arranged on the water outlet side of the ascending submerged flow artificial wetland (3); a plurality of water distribution main channels (410) are arranged on the descending submerged flow artificial wetland (4); sewage in the ascending submerged flow artificial wetland (3) flows into the water distribution main channel (410) on the descending submerged flow artificial wetland (4) via a water collection main pipe (320); and water distribution branch pipes (411) are provided on both sides of the water distribution main channel (410).

2. According to claim 1, a non-powered composite subsurface flow artificial wetland capable of effectively removing pollutants is characterized in that: The water distribution channel (1) has a mixing zone (110), a mixing zone (120) and a water distribution zone (130) which are connected in sequence along the water flow direction; a slow-release carbon source is arranged in the mixing zone (110); and the water outlet of the water distribution zone (130) is connected to a water distribution main pipe (310) of an upward submerged flow artificial wetland (3) via a water inlet pipe (2).

3. According to claim 2, a non-powered composite subsurface flow artificial wetland capable of effectively removing pollutants is characterized in that: A partition is arranged in the water distribution channel (1) along the water flow direction, and a hollow baffle is arranged in the water distribution channel (1) at the tail end of the partition along the water flow direction. The inner cavity of the water distribution channel (1) is divided into a mixing zone (110), a mixing zone (120) and a water distribution zone (130) by the partition and the hollow baffle. The mixing zone (110) is connected to the mixing zone (120) via holes on the hollow baffle, and the mixing zone (120) is connected to the water distribution zone (130) via holes on the hollow baffle.

4. According to claim 1, a non-powered composite subsurface flow artificial wetland capable of effectively removing pollutants is characterized in that: The highest point of the water distribution main channel (410) is lower than the lowest point of the water collection main pipe (320) in the upward submerged flow artificial wetland (3).

5. According to claim 1, a non-powered composite subsurface flow artificial wetland capable of effectively removing pollutants is characterized in that: The water distribution branch pipes (411) on both sides of the water distribution main channel (410) are cross-distributed, and the lowest point of the water distribution branch pipes (411) is 10 cm to 15 cm away from the bottom of the water distribution main channel (410).

6. The non-powered composite subsurface flow artificial wetland capable of effectively removing pollutants according to claim 1, characterized in that: The uppermost end of the water distribution main channel (410) is 10 cm to 15 cm higher than the planting soil layer of the downward subsurface flow artificial wetland (4).

7. The non-powered composite subsurface flow artificial wetland capable of effectively removing pollutants according to claim 1, characterized in that: The water distribution main channel (410) is provided with a hollow grate (420), and a dense wire mesh is fixed under the hollow grate (420).

8. The non-powered composite subsurface flow artificial wetland capable of effectively removing pollutants according to claim 1, characterized in that: The thickness of the packing layer of the upward submerged flow artificial wetland (3) is 60 cm to 80 cm, and the thickness of the packing layer of the downward submerged flow artificial wetland (4) is 30 cm to 50 cm.

9. The non-powered composite subsurface flow artificial wetland capable of effectively removing pollutants according to claim 1, characterized in that: A microbial migration slow-release layer (5) is arranged below the water distribution layer of the upward submerged flow artificial wetland (3) and below the water collection layer of the downward submerged flow artificial wetland (4), respectively. The microbial migration slow-release layer (5) contains microorganisms and a slow-release carbon source.

10. The non-powered composite subsurface flow artificial wetland capable of effectively removing pollutants according to claim 9, characterized in that: The microorganisms added into the microorganism migration slow-release layer (5) below the upward submerged flow artificial wetland (3) are anaerobic anoxic bacteria, and the microorganisms added into the microorganism migration slow-release layer (5) below the downward submerged flow artificial wetland (4) are aerobic bacteria.

Images