A cascade water multi-hole wetland purification system and purification method

Abstract

The application discloses a stacked water type porous wetland purification system, which comprises multiple-stage falling water wetlands with decreasing height in sequence, and the multiple-stage falling water wetlands are connected in series, wherein the number of the falling water wetlands is not less than 3; each falling water wetland comprises a gradient shallow water zone, an ecological restoration area and two filter dam falling water units; the ecological restoration area is located downstream of the gradient shallow water zone; and the two filter dam falling water units are respectively arranged at the water inlet of the gradient shallow water zone and the water outlet of the ecological restoration area on each falling water wetland. The stacked water type porous wetland purification system is provided, the multiple-stage falling water wetlands are used in series by continuous stacked water, the respective advantages of the wetlands are utilized, and the wetlands are designed in different depths and porous islets, so that the landscape effect is improved, the water reoxygenation and water flow retention time are increased, the water quality purification effect is greatly improved, and the area of the wetland is reduced.

Description

A cascading porous wetland purification system and purification method Technical Field

[0001] This invention belongs to the field of constructed wetland purification technology, and particularly relates to a cascading porous wetland purification system and purification method. Background Technology

[0002] Currently, common measures for river and lake water pollution control include in-situ ecological restoration technology and integrated equipment treatment technology. However, conventional measures are difficult to stably construct and cannot guarantee the treatment effect when dealing with flood channels and situations with large river flow, fast flow velocity, and large water area.

[0003] Constructed wetlands are artificially built and managed wetland systems that mimic the ecological functions of natural wetlands, utilizing the combined effects of plants, microorganisms, and other media to remove pollutants and purify water. Cascading constructed wetlands are a special type of constructed wetland that enhances purification by setting different water levels and flow patterns.

[0004] Currently, there are relatively few cases of using cascading constructed wetlands to treat river sewage. Existing wetland purification systems require large wetland areas, have insufficient water reoxygenation, and poor aesthetics. Summary of the Invention

[0005] The purpose of this invention is to overcome the above-mentioned problems in the existing technology and provide a cascading porous wetland purification system. By using multi-level cascading wetlands in series, the system utilizes the advantages of each wetland and incorporates designs such as different depths of wetlands and porous islets. This not only improves the landscape effect but also increases the reoxygenation of the water and the water retention time, greatly improving the water purification effect and reducing the area of ​​wetlands required.

[0006] To achieve the above-mentioned technical objectives and effects, the present invention is implemented through the following technical solution:

[0007] In a first aspect, the present invention provides a cascading porous wetland purification system, comprising a multi-stage cascading wetland with sequentially decreasing heights, wherein the multi-stage cascading wetlands are connected in series, and the number of cascading wetlands is not less than 3.

[0008] Each cascading wetland includes a tiered shallow water zone, an ecological restoration zone, and two filter dam cascading units. The ecological restoration zone is located downstream of the tiered shallow water zone, and the two filter dam cascading units are respectively located at the inlet of the tiered shallow water zone and the outlet of the ecological restoration zone on each cascading wetland.

[0009] Several porous islets are set up on the tiered shallow water zone;

[0010] Multiple porous islets are distributed on the outer side of the stepped shallow water zone, and the ground level of the porous islets is higher than that of the inner side of the stepped shallow water zone.

[0011] The ecological restoration area consists of an impermeable bottom layer, a filter layer, and a silt soil layer, arranged from bottom to top. Aquatic plants are planted in the silt soil layer.

[0012] Furthermore, the height difference between two adjacent waterfall wetlands is 15-45cm.

[0013] Furthermore, the depth of the ecological restoration zone is greater than the depth of the tiered shallow water zone;

[0014] The edges of the shallow water zone in the tiers are arc-shaped.

[0015] Furthermore, the island's surface consists of a porous filler layer and a topsoil layer;

[0016] The porous packing layer is prepared by filling porous packing into a gabion cage;

[0017] The thickness of the topsoil is 20-40cm.

[0018] Furthermore, the ground of the porous islet is covered with plant communities;

[0019] A plant community is at least one of xerophytic plant communities and hygrophytic plant communities.

[0020] Furthermore, the filter layer includes various filter media;

[0021] The filter media is any one or a combination of at least two of the following: coarse gravel, iron ore, activated carbon, or shale.

[0022] Furthermore, the bottom of the ecological restoration area is equipped with the first aeration nozzles;

[0023] Lake purifiers are also installed on the silt soil layer;

[0024] The lake purifier is equipped with biological packing material.

[0025] The lake purifier has a second aeration nozzle at the bottom.

[0026] Furthermore, the filter dam drop unit includes a settlement interception layer and an overflow dam located at the outlet of the settlement interception layer;

[0027] The settling interception layer is made of porous dephosphorization bricks;

[0028] The height of the overflow dam is higher than the water level in the cascade shallow water zone and the ecological restoration zone.

[0029] Secondly, the present invention also provides a purification method for a cascading porous wetland purification system, the purification method comprising the following steps: wastewater is transported through pipelines to a multi-stage cascading wetland for purification treatment, the water quality is purified, and then discharged into a river through pipelines for ecological water replenishment.

[0030] Furthermore, the specific purification process is as follows: Wastewater is transported to the cascading wetland, first to the filter dam cascading unit located at the inlet of the cascading shallow water zone. After the sedimentation interception layer performs preliminary sedimentation interception treatment on the wastewater, it flows out through the overflow dam and then flows sequentially through the cascading shallow water zone and the ecological restoration zone for treatment. After treatment, it flows through the filter dam cascading unit located at the outlet of the ecological restoration zone, and is treated again by the sedimentation interception layer to obtain purified water. The purified water is discharged through the overflow dam to the next level of cascading wetland.

[0031] Compared with the prior art, the beneficial effects of the present invention are:

[0032] 1. This invention utilizes a series of multi-tiered cascading wetlands to fully leverage the advantages of each type of artificial wetland. Through layer-by-layer purification by artificial wetlands, it not only enhances water quality purification by increasing oxygen levels through elevation differences and reoxygenating through cascading water, but also creates a rich habitat and experiential space, thereby improving water quality purification and achieving ecological stability of the aquatic environment. It also fosters a vibrant landscape atmosphere.

[0033] 2. By designing zones of varying depths, this invention saves on engineering work and can mitigate the destructive power of sudden rainstorms and floods. The purified water flows through porous islands in the tiered shallow water zone, which not only reduces flow velocity and extends the water flow path, promoting particulate matter sedimentation, but also achieves an "edge effect," promoting biodiversity and population density in this water-terrestrial transition zone. This results in higher water purification efficiency and a porous landscape where water and green space are fully integrated. Attached Figure Description

[0034] The accompanying drawings, which are included to provide a further understanding of the invention and form part of this application, illustrate exemplary embodiments of the invention and, together with their description, serve to explain the invention and do not constitute an undue limitation thereof. In the drawings:

[0035] Figure 1 is a schematic diagram of the cascading porous wetland purification system provided by the present invention.

[0036] Figure 2 is a schematic diagram of the structure of the cascading wetland provided by the present invention;

[0037] Figure 3 is a schematic diagram of the porous island structure provided by the present invention.

[0038] The attached diagram is labeled as follows: 1. First-level cascading wetland; 11. Filter dam cascading unit; 12. Stepped shallow water zone; 13. Ecological restoration area; 121. Porous islet; 131. Impermeable bottom layer; 132. Filter layer; 133. Silt soil layer; 134. Aquatic plants; 135. First aeration nozzle; 136. Lake purifier; 1211. Porous filler layer; 1212. Topsoil. Detailed Implementation

[0039] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0040] Example 1

[0041] As shown in Figures 1 to 3, a cascading porous wetland purification system includes multi-level, continuous cascading wetlands with sequentially decreasing heights. The multi-level cascading wetlands operate in series. Wastewater flows into the highest level of the first-level cascading wetland and is propelled from high to low by the height difference. After being purified by each level of cascading wetland, the wastewater finally passes through the lowest level of the last-level cascading wetland to complete the water purification. The number of cascading wetlands is not less than three.

[0042] The height difference between two adjacent cascading wetlands is 15-45cm;

[0043] In the actual construction process, the wetland comprehensively considers factors such as the purification principle and purification capacity of ecological wetlands, site elevation differences, and water quality.

[0044] Each cascading wetland includes a tiered shallow water zone, an ecological restoration zone, and two filter dam cascading units. The ecological restoration zone is located downstream of the tiered shallow water zone, and the two filter dam cascading units are respectively located at the inlet of the tiered shallow water zone and the outlet of the ecological restoration zone on each cascading wetland.

[0045] The cascading wetlands are designed with different depths for on-site filling and excavation based on the principle of minimizing engineering work, with the depth of the ecological restoration zone being greater than that of the cascading shallow water zone;

[0046] Several porous islets are set up on the tiered shallow water zone;

[0047] The edges of the tiered shallow water zone are arc-shaped. Specifically, the banks of the tiered shallow water zone are set in an L-shape or U-shape to increase the contact area between organisms and water and facilitate the exchange of matter and energy.

[0048] Multiple porous islets are distributed on the outer side of the stepped shallow water zone, and the ground level of the porous islets is higher than that of the inner side of the stepped shallow water zone.

[0049] The island's surface consists of a porous filler layer and a topsoil layer. The porous filler layer is made by filling porous filler into gabion cages, and the topsoil layer is 20-40 cm thick.

[0050] The ground of the porous island is covered with plant communities, which are at least one of xerophytic plant communities and hygrophytic plant communities.

[0051] Multiple porous islands of different sizes are distributed in a staggered manner. They can be constructed individually or jointly in various ways such as being separated, tangent, or intersecting.

[0052] It is equipped with multiple porous islands, and porous filler is installed at the bottom of the islands. Based on the concept of "porous", it is configured into a sponge wetland system with water-island interweaving, which has rainwater purification function.

[0053] Multiple porous islets are distributed on the outer side of the tiered shallow water zone. The ground level of the porous islets is higher than that of the inner side of the tiered shallow water zone. Therefore, based on the form of the site elevation difference, this design has the functional principle of water flowing from the outside to the inside.

[0054] The porous islets are home to plant communities that purify rainwater. These plant communities are xerophytic, hygrophytic, or a combination of xerophytic and hygrophytic, thus forming a wetland system with diverse plant habitats.

[0055] Porous islets, compared to large bodies of water of the same size, bring greater edge effects, isolation effects, ecological benefits and landscape effects to the site, creating conditions for water purification and habitat for a variety of organisms;

[0056] In the actual construction process, the porous islands are excavated on-site according to the principle of minimum work. The size of the islands is designed reasonably according to the size of the shallow water zone and the landscape effect. The bottom of the islands is filled with porous filling material in gabion cages and piled up. Then, the surface of the gabion cages filled with porous filling material is covered with the original hard and sticky surface soil, thus forming an island with undulating terrain, which can be planted with native and original wetland plants.

[0057] The ecological restoration area consists of an impermeable bottom layer, a filter layer, and a silt soil layer, arranged from bottom to top. Aquatic plants are planted in the silt soil layer.

[0058] The filter layer includes a variety of filter media, which are selected from any one or a combination of at least two of coarse gravel, iron ore, activated carbon or shale;

[0059] The first aeration nozzles are located at the bottom of the ecological restoration area;

[0060] A lake purifier is installed on the silt soil layer, with biological packing material attached to the lake purifier, and a second aeration nozzle is distributed at the bottom of the lake purifier.

[0061] By setting up a first aeration nozzle and a second aeration nozzle, in actual application, the first aeration nozzle and the second aeration nozzle are connected to the blower to set up a double-layer aeration nozzle to increase the reoxygenation of the water.

[0062] The filter dam drop unit includes a settlement interception layer and an overflow dam located at the outlet of the settlement interception layer;

[0063] The settling interception layer is made of porous dephosphorization bricks;

[0064] The height of the overflow dam is higher than the liquid level in the cascade shallow water zone and the ecological restoration zone;

[0065] Among them, porous phosphorus removal bricks utilize the concept of material coupling with ecological shoreline. Based on the ecological pore principle, they adopt river ecological embankment construction materials with continuous and interconnected pores and certain mechanical conditions as carriers for embankment habitats and wetland filter dams. While precipitating and removing phosphorus and fluoride, they can also ensure the stability of the embankment and create space for plant survival.

[0066] Overflow dams are used to regulate water levels, control gravity inflow and outflow, and complete water stacking.

[0067] This embodiment provides a cascading porous wetland purification system. By using multiple continuous cascading wetlands in series, the system increases water reoxygenation and water retention time, greatly improving the water purification effect.

[0068] Example 2

[0069] This embodiment provides a purification method for a cascading porous wetland purification system. The purification method includes the following steps: wastewater is transported through pipelines to a multi-stage cascading wetland for purification treatment, and the water quality is purified before being discharged into a river through pipelines for ecological water replenishment.

[0070] The specific process of this purification method is as follows:

[0071] Step 2.1: River bypass water, intercepted domestic sewage, agricultural non-point source pollution, initial rainwater, urban wastewater and sewage treatment plant effluent are introduced into the wetland through pipelines. By controlling the inflow rate, the hydraulic retention time of sewage in each cascade wetland is ensured to be 1-3 days.

[0072] Step 2.2: Wastewater enters through the first-stage cascading wetland filter dam cascading unit, flows through the tiered shallow water zone, ecological restoration zone and filter dam cascading unit, and decomposes and purifies pollutants through processes such as filtration, adsorption, sedimentation, plant absorption and microbial degradation. The wastewater then flows into the next stage of constructed wetland for purification treatment through gravity flow. The water quality of the wastewater after treatment by the first-stage cascading wetland is measured.

[0073] Step 2.3: Wastewater enters the next stage of constructed wetland for purification treatment. The purification treatment process is the same as in Step 2.2. After purification treatment, the wastewater flows into the next stage of constructed wetland through gravity flow. The wastewater continues to flow into the last stage of constructed wetland at the lowest point for treatment. After treatment, the wastewater enters the river through pipes, completing water purification and achieving ecological water replenishment.

[0074] The following section further explains the application of the cascading porous wetland purification system in the purification and treatment of polluted river water and rural domestic sewage, using practical examples. The cascading porous wetland purification system includes three continuous cascading wetlands with sequentially decreasing heights. The three cascading wetlands operate in series. Sewage flows into the highest cascading wetland, and is propelled from high to low by the height difference. After being purified by the first and second cascading wetlands, the water finally passes through the third cascading wetland, completing the water purification process.

[0075] Taking into account the specific conditions of the project site and water quality, a three-tiered continuous cascading wetland was connected in series, with a 25cm height difference between adjacent wetlands. Wetland plant communities were planted on the surface of the porous islets, and coarse gravel was used as the filter layer in the ecological restoration area. The specific effects of this cascading porous wetland purification system are as follows:

[0076] Polluted river water was introduced, with a treatment volume of 600m³. 3 / d, after the wetland is in stable operation, samples are taken at the inlet of the first-stage wetland and the outlet of the last-stage wetland, and monitored continuously for one week. The water quality is shown in Table 1:

[0077] Table 1. Water quality of influent and effluent

[0078]

[0079] The wastewater from rural domestic sewage treatment plant is introduced, with a treatment capacity of 300 cubic meters. 3 / d, after the wetland is operating stably, samples are taken at the inlet of the first-stage wetland and the outlet of the last-stage wetland, and monitored continuously for one week. The water quality is shown in Table 2:

[0080] Table 2. Water quality of influent and effluent

[0081]

[0082]

[0083] Based on the actual operation of the project, after treatment by the cascading porous wetland purification system, the concentration of pollutants was significantly reduced, the COD removal rate reached over 50%, the ammonia nitrogen removal rate reached over 75%, and the TP removal rate reached over 74%.

[0084] This embodiment provides the application of a cascading porous wetland purification system in the purification and treatment of polluted river water and rural domestic sewage. As can be seen from this embodiment, the concentration of pollutants is significantly reduced after the cascading porous wetland purification system is treated by a three-stage series-connected cascading wetland.

[0085] This invention provides a cascading porous wetland purification system and method. By designing zones of varying depths, it saves on engineering work and can cope with sudden rainstorms and floods, reducing their destructive power. The purified water flows through porous islands in the tiered shallow water zone, which not only reduces the flow velocity and extends the water flow path, promoting particulate matter sedimentation, but also achieves an "edge effect," promoting the increase of species diversity and population density in this water-terrestrial habitat transition zone. This results in higher water purification efficiency and a porous landscape where water and green space are fully integrated.

[0086] In the description of this specification, references to terms such as "an embodiment," "example," "specific example," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the invention. In this specification, illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0087] The foregoing has shown and described the basic principles, main features, and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited to the above embodiments. The embodiments and descriptions in the specification are merely illustrative of the principles of the invention. Various changes and modifications can be made to the invention without departing from its spirit and scope, and all such changes and modifications fall within the scope of the claimed invention.

Claims

1. A cascading porous wetland purification system, characterized in that, The system comprises a series of cascading wetlands of progressively decreasing height, with at least three cascading wetlands connected in series. Each cascading wetland includes a stepped shallow water zone, an ecological restoration zone, and two filter dam cascading units. The ecological restoration zone is located downstream of the stepped shallow water zone, and the two filter dam cascading units are respectively located at the inlet of the stepped shallow water zone and the outlet of the ecological restoration zone. Multiple porous islets are arranged on the stepped shallow water zone, distributed on the outer side of the zone, with their ground level higher than the inner side of the stepped shallow water zone. The ecological restoration area consists of an impermeable bottom layer, a filter layer, and a silt soil layer arranged sequentially from bottom to top. Aquatic plants are planted in the silt soil layer. The ground of the island is composed of a porous filler layer and a topsoil layer. The porous filler layer is prepared by filling gabion cages with porous filler. The thickness of the topsoil layer is 20-40 cm. The island has undulating terrain. The filter dam drop unit includes a settling interception layer and an overflow dam located at the outlet of the settling interception layer. The settling interception layer is constructed of porous phosphorus removal bricks. The height of the overflow dam is higher than the shallow water zone of the tiers and the liquid level of the ecological restoration area.

2. The cascading porous wetland purification system according to claim 1, characterized in that: The height difference between two adjacent waterfall wetlands is 15-45cm.

3. The cascading porous wetland purification system according to claim 1, characterized in that: The depth of the ecological restoration zone is greater than the depth of the tiered shallow water zone; the edge of the tiered shallow water zone is arc-shaped.

4. The cascading porous wetland purification system according to claim 1, characterized in that: The ground of the porous island is covered with a plant community; the plant community is at least one of xerophytic plant community and hygrophytic plant community.

5. The cascading porous wetland purification system according to claim 1, characterized in that: The filter layer includes a variety of filter media; the filter media is any one or a combination of at least two of coarse gravel, iron ore, activated carbon or shale.

6. The cascading porous wetland purification system according to claim 1, characterized in that: The bottom of the ecological restoration area is provided with a first aeration nozzle; a lake purifier is also installed on the silt soil layer; biological packing material is attached to the lake purifier; and a second aeration nozzle is provided at the bottom of the lake purifier.

7. A purification method for a cascading porous wetland purification system according to any one of claims 1-6, characterized in that, The purification method includes the following steps: wastewater is transported through pipelines to a multi-tiered cascading wetland for purification treatment, and then discharged into the river through pipelines for ecological water replenishment.

8. The purification method of a cascading porous wetland purification system according to claim 7, characterized in that, The specific process of the purification treatment is as follows: Wastewater is transported to the cascading wetland and first to the filter dam cascading unit located at the inlet of the cascading shallow water zone. After the sedimentation interception layer performs preliminary sedimentation interception treatment on the wastewater, it flows out through the overflow dam and then flows through the cascading shallow water zone and the ecological restoration zone for treatment. After treatment, it flows through the filter dam cascading unit located at the outlet of the ecological restoration zone and is treated again by the sedimentation interception layer to obtain purified water. The purified water is discharged through the overflow dam to the next level of cascading wetland.

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