Reinforced denitrification and dephosphorization device for subsurface flow wetland cloth / catchment system

Abstract

This utility model relates to an enhanced nitrogen and phosphorus removal device for a subsurface flow wetland fabric / collection system. A mesh fabric surrounds the perforated areas of the fabric and collection pipe in the subsurface flow wetland, with its ends bound and secured to the fabric and collection pipe. The space between the mesh fabric and the outer wall of the fabric and collection pipe is filled with ceramsite and a slow-release carbon source, the particle size of which is larger than the perforation size. The ceramsite and slow-release carbon source have a larger mesh size than the mesh fabric. The beneficial effects are: after the fabric wraps around the ceramsite and slow-release carbon source, the water effluent from the perforations in the distribution pipe is dispersed and redistributed to the packing layer, ensuring uniform water distribution and solving the problem of uneven water distribution in subsurface flow wetlands. The ceramsite and slow-release carbon source are close to the distribution pipe, where the water flow velocity is relatively fast. The water flow scouring action prevents excessive biofilm growth, allowing more water to enter the packing layer, improving nitrogen and phosphorus removal efficiency under low-temperature conditions in winter. The slow-release carbon source provides the carbon source needed for microbial growth, improving wastewater denitrification efficiency.

Description

Technical Field

[0001] This utility model relates to the field of subsurface flow wetland technology, specifically to an enhanced nitrogen and phosphorus removal device for subsurface flow wetland fabric / collection systems. Background Technology

[0002] Currently, subsurface flow wetlands are mainly used for domestic sewage treatment, deep purification of sewage treatment plant effluent, and circulation purification of slightly polluted water bodies. Influent enters the subsurface flow wetland through a water distribution system (water distribution pipe), and then pollutants are reduced through the absorption of wetland plants, adsorption of filler material, and degradation by microorganisms. The treated water is then collected and discharged through a water collection system (water collection pipe).

[0003] Existing wetland water distribution and collection systems utilize evenly spaced holes in the distribution and collection pipes to distribute and collect water. When using this method, in order to avoid the water flow being completely released at the front of the distribution pipe, resulting in insufficient water distribution at the rear, the number of holes in the pipe wall must be controlled to be limited and sufficient spacing must be maintained. This can lead to water flow from the holes being too concentrated, resulting in uneven water distribution in the filling area.

[0004] Under low winter temperatures, plant dormancy and reduced microbial activity lead to a significant decrease in biodegradation and plant absorption. Physicochemical adsorption and chemical precipitation within the packing material then become the primary pathways for the removal of pollutants such as nitrogen and phosphorus. However, as the wetland's service life increases, the thickness of the biofilm on the surface of existing subsurface flow wetland packing material increases, significantly reducing the proportion of water that can enter the packing material. This prevents the aforementioned processes from being fully utilized. Furthermore, existing subsurface flow wetlands lack the organic carbon source required for nitrate denitrification, resulting in a low total nitrogen removal capacity. Utility Model Content

[0005] The technical problem to be solved by this utility model is to provide an enhanced nitrogen and phosphorus removal device for subsurface flow wetland distribution / collection systems, so as to solve the problems of uneven water distribution in existing subsurface flow wetland distribution systems, reduced nitrogen and phosphorus removal capacity of wetlands in winter due to thickening of biofilm between packing materials in subsurface flow wetlands, and low total nitrogen removal capacity of subsurface flow wetlands due to insufficient carbon source.

[0006] The technical solution of this utility model to solve the above-mentioned technical problems is as follows:

[0007] An enhanced nitrogen and phosphorus removal device for a subsurface flow wetland fabric / collection system includes: a mesh fabric, which surrounds and wraps the area where the fabric and collection pipe have holes in the subsurface flow wetland, and its two ends are tied and fastened to the fabric and collection pipe; the space between the mesh fabric and the outer wall of the fabric and collection pipe is filled with ceramic particles with a particle size larger than the hole size and a slow-release carbon source.

[0008] The beneficial effects of this utility model are:

[0009] The water distribution pipe is wrapped with expanded clay aggregate and slow-release carbon source through a mesh fabric. This disperses the water effluent from the holes in the pipe and redistributes it to the packing layer, ensuring uniform water distribution and solving the problem of uneven water distribution in subsurface flow wetlands. The expanded clay aggregate and slow-release carbon source are close to the water distribution pipe, where the water flow velocity is relatively fast. The water flow scouring action prevents the biofilm from becoming too thick and allows more water to enter the packing layer, ensuring the packing layer's adsorption, precipitation, and removal efficiency of pollutants such as nitrogen and phosphorus in the water. This improves the removal efficiency of nitrogen and phosphorus under low-temperature conditions in winter. The slow-release carbon source provides the carbon element necessary for the growth of microorganisms in the subsurface flow wetland and can continuously exert a highly efficient decontamination effect, providing them with biological carbon and growth factors to improve the denitrification efficiency of wastewater. The slow-release carbon source has strong slow-release performance, continuously providing the carbon source needed for microbial growth without any negative pollution impact on the environment.

[0010] Based on the above technical solution, the present invention can be further improved as follows.

[0011] Furthermore, the particle size of the ceramsite is 20mm to 30mm, and the particle size of the slow-release carbon source is 10mm to 30mm.

[0012] Furthermore, the volume ratio of ceramsite to slow-release carbon source is 0.89–0.93:0.07–0.11.

[0013] Furthermore, the expanded clay aggregate is made of polyferric composite expanded clay aggregate specifically designed for water purification.

[0014] The further beneficial effects of adopting the above are: compared with traditional ceramsite, it has better pollutant removal efficiency, can enhance the phosphorus fixation effect of the filler, and greatly improve the phosphorus removal efficiency. The principle is: adding sponge iron to the raw materials can produce a combined biological-chemical phosphorus removal effect, and sponge iron can enhance the phosphorus removal efficiency of the system.

[0015] Furthermore, a composite biological enzyme preparation is filled between the mesh fabric and the outer wall of the water collection pipe.

[0016] The further beneficial effects of adopting the above are: it has the characteristics of high efficiency catalysis, high specificity, and environmental friendliness, and its core function is to accelerate the removal of pollutants through enzymatic reaction.

[0017] Furthermore, the particle size of the compound biological enzyme preparation 4 is 0.2–1.6 mm, and the addition amount of the compound biological enzyme preparation is 1–1.5 kg / m³. 3 .

[0018] Furthermore, the total thickness of the ceramic particles, slow-release carbon source, and composite biological enzyme preparation filling the gaps between the mesh fabric and the outer wall of the water collection pipe is 180mm to 200mm.

[0019] Furthermore, the mesh fabric is made of glass fiber with a specification of 160g / m².2 ~180g / m 2 The mesh size is 3mm~5mm×3mm~5mm.

[0020] Furthermore, the subsurface flow wetland is a downward flow subsurface flow wetland, with non-woven fabric covering the top of the mesh fabric.

[0021] The further beneficial effect of adopting the above is that the non-woven fabric prevents the upper planting soil from entering and clogging the filler area.

[0022] Furthermore, the nonwoven fabric has a specification of 180g / m². 2 ~200g / m 2 . Attached Figure Description

[0023] Figure 1 This is a structural diagram of the enhanced nitrogen and phosphorus removal device used in the subsurface flow wetland fabric / water collection system of this utility model.

[0024] The attached diagram lists the components represented by each number as follows:

[0025] 1. Mesh fabric, 2. Ceramsite, 3. Slow-release carbon source, 4. Compound biological enzyme preparation, 5. Non-woven fabric, 6. Subsurface flow wetland, 610. Water distribution pipe. Detailed Implementation

[0026] The principles and features of this utility model are described below with reference to the accompanying drawings. The examples given are only for explaining this utility model and are not intended to limit the scope of this utility model.

[0027] Example 1

[0028] like Figure 1 As shown, an enhanced nitrogen and phosphorus removal device for a subsurface flow wetland fabric / collection system includes: a mesh fabric 1, which surrounds and wraps around the area with holes in the water distribution pipe in the subsurface flow wetland 6, with both ends of the mesh fabric 1 bound and fastened to the water distribution pipe; and a mesh fabric 1 which surrounds and wraps around the area with holes in the water collection pipe in the subsurface flow wetland 6, with both ends of the mesh fabric 1 bound and fastened to the water collection pipe, so as to... Figure 1 Taking the structure shown as an example: the mesh cloth 1 surrounds the area where the water distribution pipe 610 has holes in the subsurface flow wetland 6. The space between the mesh cloth 1 and the outer wall of the water distribution pipe is filled with ceramsite 2 and slow-release carbon source 3. The space between the mesh cloth 1 and the outer wall of the water collection pipe is filled with ceramsite 2 and slow-release carbon source 3. The particle size of the ceramsite 2 is larger than the hole size and the particle size of the ceramsite 2 is larger than the mesh size of the mesh cloth 1. The particle size of the slow-release carbon source 3 is larger than the hole size and the particle size of the slow-release carbon source 3 is larger than the mesh size of the mesh cloth 1.

[0029] A filling area is formed between the mesh fabric 1 and the outer wall of the water distribution pipe or between the mesh fabric 1 and the outer wall of the water collection pipe. The expanded clay granules 2 and the slow-release carbon source 3 are filled in the filling area. After filling the mesh fabric 1 with expanded clay granules 2 and the slow-release carbon source 3 between the mesh fabric 1 and the outer wall of the water collection pipe, the expanded clay granules 2 and the slow-release carbon source 3 are first arranged evenly and flat. Then, the mesh fabric 1 can be sewn closed with nylon cable ties. Of course, this is just an example of one method. In actual application, other methods are not excluded. For example, the mesh fabric 1 is first sewn into a tube shape with thread, and then the ends of the tube mesh fabric 1 are tied with cable ties.

[0030] After the water distribution pipe is wrapped with ceramsite 2 and slow-release carbon source 3 by mesh cloth 1, the water effluent from the holes in the water distribution pipe is dispersed and then redistributed to the packing layer, ensuring uniform water distribution and solving the problem of uneven water distribution in subsurface flow wetlands. Ceramsite 2 and slow-release carbon source 3 are close to the water distribution pipe, and the water flow speed is relatively fast. The water flow scouring action prevents the biofilm from becoming too thick and multiplying, allowing more water to enter the interior of the packing, ensuring the adsorption, precipitation and removal effect of pollutants such as nitrogen and phosphorus in the water by the packing, and improving the nitrogen and phosphorus removal effect under low temperature conditions in winter. Slow-release carbon source 3 provides the carbon element necessary for the growth of microorganisms in the subsurface flow wetland 6, and can continuously exert a highly efficient decontamination effect, providing them with biological carbon and growth factors to improve the denitrification efficiency of wastewater. Slow-release carbon source 3 has strong slow-release performance, continuously providing the carbon source required for the growth of microorganisms, without negative pollution impact on the environment.

[0031] In this embodiment, the slow-release carbon source 3 is preferably the MDI chemically modified high-efficiency slow-release carbon source described in the patent document with application number 2024111291606.

[0032] Example 2

[0033] like Figure 1 As shown, this embodiment is a further improvement on embodiment 1, as detailed below:

[0034] The preferred particle size of the expanded clay granules 2 is 20mm to 30mm, and the preferred particle size of the slow-release carbon source 3 is 10mm to 30mm. Furthermore, the volume ratio of expanded clay granules 2 to slow-release carbon source 3 is 0.89 to 0.93: 0.07 to 0.11, for example, the volume ratio of expanded clay granules 2 to slow-release carbon source 3 is 0.93: 0.07; or, the volume ratio of expanded clay granules 2 to slow-release carbon source 3 is 0.89: 0.11.

[0035] Example 3

[0036] like Figure 1 As shown, this embodiment is a further improvement on embodiment 1 or 2, as detailed below:

[0037] The expanded clay granules 2 are special expanded clay granules for water purification using polyferric composite materials. The components of the polyferric composite expanded clay granules 2 for water purification include: clay, biological sludge and sponge iron. The volume ratio of clay, biological sludge and sponge iron is 6-9:1-2:0.6-1. In this embodiment, the biological sludge is the dewatered sludge from a conventional sewage treatment plant in the prior art.

[0038] The processing method of polyferric composite ceramsite for water purification is as follows:

[0039] The raw materials are first pre-treated, which can be sieving, crushing and drying in sequence.

[0040] The raw material pellets are then processed by granulation.

[0041] The raw material balls are then dried at a temperature of 105℃±5℃ for 2 to 3 hours.

[0042] Then preheat at 300℃~350℃ for 1h~1.5h;

[0043] Finally, the temperature is raised to 1150℃~1200℃ for sintering for 1.5h~2h, and after cooling, polyferric composite water purification special ceramic particles can be obtained.

[0044] In this embodiment, the particle size of the polyferric composite water purification ceramsite is 20mm-30mm, and the bulk density is 200kg / m³. 3 ~400kg / m 3 Porosity > 65%, compressive strength of cylinder is 0.8 MPa to 1.0 MPa, water absorption rate is 20% to 25%, particle shape coefficient is ≤ 2.0, mud content is ≤ 3.0%, boiling mass loss is ≤ 5.0%, and loss on ignition is ≤ 5.0%.

[0045] Compared with traditional ceramsite, the obtained ceramsite has better pollutant removal efficiency, which can enhance the phosphorus fixation effect of the filler and greatly improve the phosphorus removal efficiency. The principle is that adding sponge iron to the raw materials can produce a combined biological-chemical phosphorus removal effect, and sponge iron can enhance the phosphorus removal efficiency of the system.

[0046] Example 4

[0047] like Figure 1 As shown, this embodiment is a further improvement on embodiment 1, 2, or 3, as detailed below:

[0048] The mesh cloth 1 is filled with a composite biological enzyme preparation 4 between itself and the outer wall of the water distribution pipe. The composite biological enzyme preparation 4 is a prior art product, which is a catalytic biological product composed of dehydrogenase, amylase and protease. It has the characteristics of high efficiency catalysis, high specificity and environmental friendliness. Its core function is to accelerate the removal of pollutants through enzymatic reaction.

[0049] The particle size of compound biological enzyme preparation 4 is 0.2 mm to 1.6 mm, and the addition amount of compound biological enzyme preparation 4 is 1 kg / m³. 3 ~1.5kg / m 3 .

[0050] Example 5

[0051] like Figure 1 As shown, this embodiment is a further improvement on embodiment 4, as detailed below:

[0052] The total thickness of the ceramic particles 2, slow-release carbon source 3, and compound biological enzyme preparation 4 filling the space between the mesh cloth 1 and the outer wall of the water distribution pipe is 180mm to 200mm. The total thickness of the ceramic particles 2, slow-release carbon source 3, and compound biological enzyme preparation 4 filling the space between the mesh cloth 1 and the outer wall of the water collection pipe is 180mm to 200mm.

[0053] Example 6

[0054] like Figure 1 As shown, this embodiment is a further improvement on any one of embodiments 1 to 5, as detailed below:

[0055] The mesh fabric 1 is preferably made of glass fiber mesh fabric 1, which is corrosion-resistant, wear-resistant, and resistant to salt and alkali. The specification of mesh fabric 1 is 160g / m. 2 ~180g / m 2 The mesh size is 3mm~5mm×3mm~5mm. The width of the mesh cloth 1 (this width refers to the direction perpendicular to the cloth and the water collection pipe) can be selected according to the length of the cloth and the water collection pipe, for example, 1000mm.

[0056] Example 7

[0057] like Figure 1 As shown, this embodiment is a further improvement on any one of embodiments 1 to 6, as detailed below:

[0058] Subsurface flow wetland 6 is a downward subsurface flow wetland, meaning that subsurface flow wetland 6 adopts an upward water distribution method, with non-woven fabric 5 covering the top of the mesh fabric 1. Figure 1As shown, the mesh fabric 1 surrounds the area with holes in the water distribution pipe 610 in the subsurface flow wetland 6. The non-woven fabric 5 is located between the planting layer and the filler layer. The function of the non-woven fabric 5 is to prevent the upper planting soil from entering and clogging the filler area. The specification of the non-woven fabric 5 can be 180g / m³. 2 ~200g / m 2 .

[0059] Although embodiments of the present invention have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting the present invention. Those skilled in the art can make changes, modifications, substitutions and variations to the above embodiments within the scope of the present invention.

Claims

1. An enhanced nitrogen and phosphorus removal device for subsurface flow wetland fabric / water collection systems, characterized in that, include: Mesh cloth (1) surrounds and wraps the area where the cloth and water collection pipe have holes in the subsurface flow wetland (6), and its two ends are tied and fastened to the cloth and water collection pipe; the mesh cloth (1) and the outer wall of the cloth and water collection pipe are filled with ceramic particles (2) with a particle size larger than the hole size and slow-release carbon source (3), and the particle size of the ceramic particles (2) and slow-release carbon source (3) is larger than the mesh size of the mesh cloth (1).

2. The enhanced nitrogen and phosphorus removal device for subsurface flow wetland fabric / water collection systems according to claim 1, characterized in that, The particle size of the ceramsite (2) is 20mm to 30mm, and the particle size of the slow-release carbon source (3) is 10mm to 30mm.

3. The enhanced nitrogen and phosphorus removal device for subsurface flow wetland fabric / water collection systems according to claim 2, characterized in that, The volume ratio of the ceramsite (2) to the slow-release carbon source (3) is 0.89-0.93:0.07-0.

11.

4. The enhanced nitrogen and phosphorus removal device for subsurface flow wetland fabric / water collection systems according to any one of claims 1 to 3, characterized in that, The ceramsite (2) is a special ceramsite for water purification using polyferric composite material.

5. The enhanced nitrogen and phosphorus removal device for subsurface flow wetland fabric / water collection systems according to any one of claims 1 to 3, characterized in that, The mesh fabric (1) is filled with a composite biological enzyme preparation (4) between itself and the outer wall of the water collection pipe.

6. The enhanced nitrogen and phosphorus removal device for subsurface flow wetland fabric / water collection systems according to claim 5, characterized in that, The particle size of the compound biological enzyme preparation (4) is 0.2 mm to 1.6 mm, and the addition amount of the compound biological enzyme preparation (4) is 1 kg / m³. 3 ~1.5kg / m 3 .

7. The enhanced nitrogen and phosphorus removal device for subsurface flow wetland fabric / water collection systems according to claim 5, characterized in that, The total thickness of the ceramic particles (2), slow-release carbon source (3), and compound biological enzyme preparation (4) filling the space between the mesh cloth (1) and the cloth and the outer wall of the water collection pipe is 180mm to 200mm.

8. The enhanced nitrogen and phosphorus removal device for subsurface flow wetland fabric / water collection systems according to claim 1, characterized in that, The mesh fabric (1) is made of glass fiber mesh fabric with a specification of 160g / m. 2 ~180g / m 2 The mesh size is 3mm~5mm×3mm~5mm.

9. The enhanced nitrogen and phosphorus removal device for subsurface flow wetland fabric / water collection systems according to claim 1, characterized in that, The subsurface flow wetland (6) is a downflow subsurface flow wetland, and the mesh fabric (1) is covered with non-woven fabric (5).

10. The enhanced nitrogen and phosphorus removal device for subsurface flow wetland fabric / water collection systems according to claim 9, characterized in that, The nonwoven fabric (5) has a specification of 180g / m². 2 ~200g / m 2 .

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