Vertical flow constructed wetland for strengthening treatment of agricultural non-point source pollution in narrow waterfront space

Abstract

The utility model relates to a vertical flow constructed wetland for strengthening treatment of agricultural non-point source pollution in a narrow waterfront space, which comprises an ecological interception ditch, an ecological filter tank and a sunken subsurface flow constructed wetland which are sequentially arranged on a lakeside shoreline zone from top to bottom and are communicated in a self-flowing manner, and the proportion of an unsaturated region of the sunken subsurface flow constructed wetland is 50-100%; and rope-shaped artificial aquatic plants are arranged in an unsaturated region in the sunken subsurface flow constructed wetland. The device has the beneficial effects that the narrow environment of a lakeside shoreline zone is fully utilized to treat non-point source pollution, the engineering land can be reduced, the ecological filter tank is arranged before sewage enters the sunken subsurface flow constructed wetland, suspended matters can be intercepted, the blockage of the sunken subsurface flow constructed wetland is slowed down, and the device is energy-saving, green and ecological, and has a good application prospect. The rope-shaped artificial aquatic plants are added into the artificial wetland and a certain unsaturated region is arranged, so that the removal of NH4 < + >-N and COD (Chemical Oxygen Demand) can be improved.

Description

Technical Field

[0001] The utility model relates to the technical field of agricultural non-point source pollution treatment, in particular to a vertical-flow constructed wetland for strengthening the treatment of agricultural non-point source pollution in a narrow waterfront space. Background Technique

[0002] Agricultural non-point source pollution is one of the most intractable problems in environmental pollution control in countries around the world today. Its pollutants mainly come from three major pollution sources: livestock and poultry breeding, aquaculture production, and rural life in the urban-rural fringe. They mainly include COD, N, P, etc. in manure and urine, and nitrogen and phosphorus in farmland flowing into water bodies with precipitation or irrigation through soil erosion, runoff, leaching, etc., causing water pollution. Agricultural non-point source pollution has large spatio-temporal variability, complex generation mechanisms, and strong randomness. If not treated in time, it is extremely easy to cause problems such as water body blackening, odor, and eutrophication. To control farmland runoff pollution, physical, chemical, and biological methods are mainly used to construct interception or purification projects to control farmland runoff pollution. According to investigations, residences and farmlands are generally near rivers, resulting in non-point source pollution easily entering rivers, causing high NH4 + -N and COD in rivers. Coupled with the generally narrow shoreline belts of lakes in waterfront spaces, traditional methods for treating non-point source pollution (such as large land occupation and unsatisfactory pollutant treatment) will no longer apply. The Ministry of Water Resources has also proposed that dike projects should pay attention to ecological protection, prevent overly hardened, whitened, and canalized slopes, and should actively adopt ecological technologies for slope protection and bank protection. Therefore, how to deal with sewage with a small repair space and excessive content of pollutants such as NH4 + -N and COD has become the key to controlling agricultural non-point source pollution in narrow waterfront spaces. Content of the Utility Model

[0003] The technical problem to be solved by the utility model is to provide a vertical-flow constructed wetland for strengthening the treatment of agricultural non-point source pollution in a narrow waterfront space to overcome the above-mentioned deficiencies in the prior art.

[0004] The technical solution of the utility model to solve the above technical problem is as follows: A vertical-flow constructed wetland for strengthening the treatment of agricultural non-point source pollution in a narrow waterfront space, including: an ecological interception ditch, an ecological filtration pond, and a subsurface-flow constructed wetland arranged in sequence from top to bottom along the lakeshore line belt and connected in a self-flow manner. The proportion of the unsaturated zone in the subsurface-flow constructed wetland is 50% - 100%, and rope-shaped artificial aquatic plants are arranged in the unsaturated zone in the subsurface-flow constructed wetland.

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

[0006] The ecological interception ditch is used for water distribution of sewage, increasing the dissolved oxygen in the sewage, enhancing the ammonia oxidation effect, and strengthening the removal of ammonia nitrogen. Then the sewage enters the ecological filtration pond by gravity flow. The ecological filtration pond filters the suspended solids and further degrades the pollutants. Subsequently, the sewage enters the subsurface flow constructed wetland. The subsurface flow constructed wetland has an unsaturated zone of 50% - 100%, which can enhance the ammonia oxidation reaction and denitrification reaction in the wetland, and synchronously strengthen the removal of nitrate nitrogen and ammonia nitrogen. The rope-shaped artificial aquatic plants arranged in the unsaturated zone of the subsurface flow constructed wetland can extend the hydraulic retention time, improve the biofilm formation rate of organisms, and increase the dissolved oxygen of the influent. At the same time, it can also strengthen the reduction of NH4 + -N and COD in the subsurface flow constructed wetland, reduce the project land area, and make the sewage meet the discharge standards;

[0007] The lakeshore line zone is generally narrow. In the present utility model, the subsurface flow constructed wetland is used as the main body of the lakeshore line zone to fully utilize the narrow environment of the lakeshore line zone to treat non-point source pollution, which can not only reduce the project land area but also enhance the reduction of non-point source pollutants;

[0008] By means of the ecological interception ditch and setting a certain unsaturated zone in the subsurface flow constructed wetland, it is beneficial to increase the dissolved oxygen in the influent and enhance the removal rate of NH4 + -N;

[0009] Before the sewage enters the subsurface flow constructed wetland, an ecological filtration pond is set up to intercept the suspended solids and slow down the blockage of the subsurface flow constructed wetland;

[0010] When the wetland operates, the influent only needs to rely on the action of gravity, and the pollutants are gradually reduced when passing through the constructed wetland, achieving the purpose of water purification. The whole process requires no other energy consumption, and is green and ecological.

[0011] On the basis of the above technical solutions, the present utility model can also be improved as follows.

[0012] Further, amphibious plants are planted at the bottom of the ecological interception ditch.

[0013] The beneficial effect of adopting the above is: using plants to initially degrade pollutants.

[0014] Further, amphibious plants are planted on the ecological filtration pond.

[0015] Further, the density of the rope-shaped artificial aquatic plants arranged in the unsaturated zone of the subsurface flow constructed wetland is 4 plants / m 2 ~8 plants / m 2 .

[0016] Further, the substrate filled in the ecological filtration pond is a mixture of gravel, volcanic rock, and limestone.

[0017] The further beneficial effects are as follows: it can not only stabilize the slope body, but also reduce non-point source pollution.

[0018] Furthermore, the substrate filled in the subsurface flow constructed wetland is a mixture of gravel, volcanic rock, and limestone.

[0019] The further beneficial effects are as follows: it can not only stabilize the slope body, but also reduce non-point source pollution.

[0020] Furthermore, emergent plants are planted on the subsurface flow constructed wetland.

[0021] The further beneficial effects are as follows: the emergent plants are used for soil fixation and absorption of pollutants for their own growth and reproduction.

[0022] Furthermore, the outer frame of the ecological interception ditch adopts a brick-concrete structure, the outer frame of the ecological filtration pond adopts a brick-concrete structure, and the outer frame of the subsurface flow constructed wetland adopts a brick-concrete structure.

[0023] The further beneficial effects are as follows: it can stabilize the slope body and prevent the collapse of the lakeside bank zone.

[0024] Furthermore, a number of stones are arranged at the outlet of the subsurface flow constructed wetland.

[0025] The further beneficial effects are as follows: it is used to buffer the water body and increase the beauty. Description of the Drawings

[0026] Figure 1 It is a side view of the vertical flow constructed wetland for treating agricultural non-point source pollution by strengthening the narrow waterfront space in the present utility model;

[0027] Figure 2 It is a top view of the vertical flow constructed wetland for treating agricultural non-point source pollution by strengthening the narrow waterfront space in the present utility model;

[0028] Figure 3 It is the influent and effluent concentrations and removal rates of each treatment group in Example 1.

[0029] In the drawings, the list of components represented by each reference numeral is as follows:

[0030] 1. Ecological interception ditch, 110. Amphibious plants, 2. Ecological filtration pond, 210. Hydrophytes, 3. Subsurface flow constructed wetland, 310. Emergent plants, 4. Rope-shaped artificial aquatic plants, 5. Stones. Detailed Embodiments

[0031] The principles and features of the present utility model are described below in conjunction with the drawings. The examples given are only for explaining the present utility model and are not intended to limit the scope of the present utility model.

[0032] Example 1

[0033] As Figure 1 , Figure 2 shown, a vertical flow constructed wetland for enhancing the treatment of agricultural non - point source pollution in narrow waterfront spaces includes: an ecological interception ditch 1, an ecological filtration pond 2, and a sunken subsurface flow constructed wetland 3, which are arranged in sequence from top to bottom in the lakeside shoreline zone and are connected by gravity flow. The proportion of the unsaturated zone in the sunken subsurface flow constructed wetland 3 is 50% - 100%, that is, a certain liquid level (0 - 50%) is set in the sunken subsurface flow constructed wetland 3, and rope - shaped artificial aquatic plants 4 are arranged in the unsaturated zone of the sunken subsurface flow constructed wetland 3.

[0034] The ecological interception ditch 1 is used for water distribution of sewage, increasing the dissolved oxygen in the sewage, enhancing the ammonia oxidation effect, and strengthening the removal of ammonia nitrogen. Then the sewage enters the ecological filtration pond 2 by gravity flow. The ecological filtration pond 2 filters the suspended solids and further degrades the pollutants. Subsequently, the sewage enters the sunken subsurface flow constructed wetland 3. The sunken subsurface flow constructed wetland 3 has an unsaturated zone of 50% - 100%, which can enhance the ammonia oxidation reaction and denitrification reaction in the wetland, and synchronously strengthen the removal of nitrate nitrogen and ammonia nitrogen. The rope - shaped artificial aquatic plants 4 arranged in the unsaturated zone of the sunken subsurface flow constructed wetland 3 can extend the hydraulic retention time, improve the bio - film formation rate of organisms, and increase the dissolved oxygen of the influent. At the same time, it can also strengthen the reduction of NH4 + -N and COD, reduce the project land area, and make the sewage meet the discharge standards.

[0035] The lakeside shoreline zone is generally narrow. In the present utility model, the sunken subsurface flow constructed wetland 3 is used as the main body of the lakeside shoreline zone to make full use of the narrow environment of the lakeside shoreline zone to treat non - point source pollution, which can not only reduce the project land area but also enhance the reduction of non - point source pollutants;

[0036] By the ecological interception ditch 1 and setting a certain unsaturated zone in the sunken subsurface flow constructed wetland 3, it is beneficial to increase the dissolved oxygen in the influent and enhance the removal rate of NH4 + -N;

[0037] An ecological filtration pond 2 is set before the sewage enters the sunken subsurface flow constructed wetland 3, which can intercept the suspended solids and slow down the blockage of the sunken subsurface flow constructed wetland 3;

[0038] When the wetland operates, the influent only needs to rely on the action of gravity, and gradually reduces the pollutants when passing through the constructed wetland, achieving the purpose of water purification. The whole process requires no other energy consumption, and is green and ecological.

[0039] The test data of pollutant reduction in the sunken subsurface flow constructed wetland 3 are shown in Table 1:

[0040] Table 1 COD and NH4 in each treatment group + - Influent and effluent concentrations and removal rates of N

[0041]

[0042] It can be seen from the experimental data that adding an unsaturated zone (100%) to the subsurface flow constructed wetland 3 can significantly improve the removal rate of NH4 + - N compared with the blank control group (45.45%), and the removal rate is increased by 54.55%. Adding a certain amount of rope-shaped artificial aquatic plants (79.14%) to the unsaturated subsurface flow constructed wetland 3 can improve the removal rate of COD compared with not adding rope-shaped artificial aquatic plants (57.41%), and the removal rate is increased by 21.73%. That is, adding rope-shaped artificial aquatic plants and a certain flooding depth in the unsaturated zone of the subsurface flow constructed wetland 3 can significantly improve the removal of NH4 + - N and COD, as Figure 3 shown.

[0043] The ecological intercepting ditch 1 preferably uses upper-end water outlet, and the ecological filtration pond 2 preferably uses upper-end water inlet and lower-end water outlet. The water outlet at the upper end of the ecological intercepting ditch 1 is connected to the water inlet at the upper end of the ecological filtration pond 2 through a pipeline, and the water outlet at the lower end of the ecological filtration pond 2 is connected to the water inlet of the water distribution pipe in the subsurface flow constructed wetland 3.

[0044] Example 2

[0045] As Figure 1 、 Figure 2 shown, this example is a further improvement on the basis of Example 1, specifically as follows:

[0046] Amphibious plants 110 are planted at the bottom of the ecological intercepting ditch 1 to initially degrade pollutants by using the amphibious plants 110.

[0047] Furthermore: Amphibious plants 210 are planted on the ecological filtration pond 2.

[0048] Example 3

[0049] As Figure 1 、 Figure 2 shown, this example is a further improvement on the basis of Example 1 or 2, specifically as follows:

[0050] The density of the rope-shaped artificial aquatic plants 4 arranged in the unsaturated zone of the subsurface flow constructed wetland 3 is 4 roots / m 2 ~8 roots / m 2 .

[0051] Example 4

[0052] As Figure 1 、Figure 2 As shown, this embodiment is a further improvement based on any one of Embodiments 1 to 3, specifically as follows:

[0053] The substrate filled in the ecological filtration pond 2 is a mixture of gravel, volcanic rock, and limestone, which can not only stabilize the slope but also reduce non-point source pollution. Furthermore, the substrate filled in the subsurface flow constructed wetland 3 is a mixture of gravel, volcanic rock, and limestone, which can not only stabilize the slope but also reduce non-point source pollution.

[0054] Embodiment 5

[0055] As Figure 1 , Figure 2 shown, this embodiment is a further improvement based on any one of Embodiments 1 to 4, specifically as follows:

[0056] Emergent plants 310 are planted on the subsurface flow constructed wetland 3, and the emergent plants 310 are used for soil fixation and absorption of pollutants for their own growth and reproduction.

[0057] Embodiment 6

[0058] As Figure 1 , Figure 2 shown, this embodiment is a further improvement based on any one of Embodiments 1 to 5, specifically as follows:

[0059] The outer frame of the ecological interception ditch 1 adopts a brick-concrete structure, the outer frame of the ecological filtration pond 2 adopts a brick-concrete structure, and the outer frame of the subsurface flow constructed wetland 3 adopts a brick-concrete structure, which can stabilize the slope.

[0060] Embodiment 7

[0061] As Figure 1 shown, this embodiment is a further improvement based on any one of Embodiments 1 to 6, specifically as follows:

[0062] A number of stones 5 are arranged at the outlet of the subsurface flow constructed wetland 3 to buffer the water body and increase the beauty.

[0063] In addition, water-drought plants can be planted on the upper part of the constructed wetland to prevent soil erosion and slope collapse.

[0064] Although the embodiments of the present invention have been shown and described above, it can be understood that the above embodiments are exemplary and should not be construed as limiting the present invention. Those of ordinary skill in the art can make changes, modifications, substitutions, and variations to the above embodiments within the scope of the present invention.

Claims

1. A vertical flow artificial wetland for strengthening narrow waterfront space to treat agricultural non-point source pollution, characterized in that: include: An ecological interception ditch (1), an ecological filtration pool (2) and a submerged submerged flow artificial wetland (3) are arranged in sequence from top to bottom on the lake shoreline and connected by gravity, wherein the unsaturated area ratio of the submerged submerged flow artificial wetland (3) is 50% to 100%, and rope-shaped artificial aquatic plants (4) are arranged in the unsaturated area of ​​the submerged submerged flow artificial wetland (3).

2. The vertical flow artificial wetland for strengthening narrow waterfront space to treat agricultural non-point source pollution according to claim 1 is characterized in that: Aquatic and amphibious plants (110) are planted at the bottom of the ecological interception ditch (1).

3. The vertical flow artificial wetland for strengthening narrow waterfront space to treat agricultural non-point source pollution according to claim 1 is characterized in that: Aquatic and drought-resistant plants (210) are planted on the ecological filtration pool (2).

4. The vertical flow artificial wetland for strengthening narrow waterfront space to treat agricultural non-point source pollution according to claim 1 is characterized in that: The density of the rope-shaped artificial waterweed (4) arranged in the unsaturated zone of the submerged submerged artificial wetland (3) is 4 roots / m 2 ~8 pieces / m 2 .

5. The vertical flow artificial wetland for strengthening narrow waterfront space to treat agricultural non-point source pollution according to claim 1, characterized in that: The matrix filled in the ecological filtration pool (2) is a mixture of crushed stone, volcanic rock and limestone.

6. The vertical flow artificial wetland for strengthening narrow waterfront space to treat agricultural non-point source pollution according to claim 1 is characterized in that: The matrix filled in the sunken subsurface flow artificial wetland (3) is a mixture of crushed stone, volcanic rock and limestone.

7. The vertical flow artificial wetland for strengthening narrow waterfront space to treat agricultural non-point source pollution according to claim 1, characterized in that: Emergent plants (310) are planted on the sunken submerged flow artificial wetland (3).

8. The vertical flow artificial wetland for strengthening narrow waterfront space to treat agricultural non-point source pollution according to claim 1, characterized in that: The outer frame of the ecological interception ditch (1) adopts a brick-concrete structure, the outer frame of the ecological filtration pool (2) adopts a brick-concrete structure, and the outer frame of the sunken submerged flow artificial wetland (3) adopts a brick-concrete structure.

9. The vertical flow artificial wetland for strengthening narrow waterfront space to treat agricultural non-point source pollution according to claim 1, characterized in that: A plurality of stones (5) are arranged outside the sinking submerged flow artificial wetland (3) at its water outlet.

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