Low-cost combined high-efficiency denitrification and dephosphorization device

Abstract

The utility model discloses a low -cost combined high -efficient denitrification and phosphorus removal device, including floating bed pool, biological floating bed, upper baffle and filter column. The granular base layer is laid to the bottom of floating bed pool and is equipped with aeration device, and there is high and low vertical baffle and forms "S" type channel in it, the height of biological floating bed's floating bed board is adjustable, and carries the water culture plant, the upper baffle is located above biological floating bed and is adjustable in height, and is equipped with light supplementing lamp at the bottom, the filter column is installed in the upper baffle bottom, and there is specific filling structure in it, and the adsorbent is 100 mesh broken plasterboard of 150 DEG C low temperature pyrolysis. The device is combined through biological floating bed and filter column, and realizes high -efficient denitrification and phosphorus removal through circulation backflow, and is low in cost, easy to operate, and is free of secondary pollution, and is suitable for promotion.

Description

Technical Field

[0001] This utility model relates to water treatment, specifically to a low-cost, combined, high-efficiency nitrogen and phosphorus removal device. Background Technology

[0002] Phosphorus is a non-renewable resource in crop growth and agricultural production. However, large amounts of phosphorus are discharged into the environment, leading not only to resource waste but also to eutrophication of water bodies due to excessive phosphorus levels. Nitrogen in water exists mainly in three forms: ammonia nitrogen, nitrate nitrogen, and nitrite. When nitrite nitrogen in water is too high, drinking this water will cause it to combine with proteins to form nitrosamines, a potent carcinogen. Long-term consumption is extremely harmful to health. Excessive nitrogen also causes eutrophication. The harms of eutrophication are mainly twofold: First, excessive nutrients lead to the proliferation of algae, which cover the water surface, reducing light transmittance and oxygen content, inhibiting photosynthesis and respiration of aquatic plants, ultimately resulting in a sharp decline in aquatic life and severely disrupting the integrity of the food chain. Second, it pollutes water sources. Large amounts of algae growing on the water surface form clumps, providing attachment points for plankton, organic pollutants, and other water pollutants. These substances can form toxic substances and dangerous gases, which remain in the fish and shrimp in the water.

[0003] Biological floating bed technology removes nitrogen and phosphorus through natural processes such as plant root absorption, microbial degradation, and matrix adsorption. It offers advantages such as eliminating the need for chemical additives, avoiding secondary pollution, and lower cost. Currently, regarding phosphorus removal methods, a utility model patent (publication number: CN101817591A) describes a self-oxygenating composite floating bed for enhanced biological nitrogen and phosphorus removal, achieving a total phosphorus removal rate of up to 73.99% in 8 days. Another utility model patent (publication number: CN115321681A) describes an enhanced ecological floating bed for nitrogen and phosphorus removal in wastewater treatment plant effluent, achieving TN and TP removal rates of 76.2% and 61.9%, respectively. However, plant growth depends on sunlight and often requires a long time to reach stable results. Therefore, combining it with other technologies is expected to address these shortcomings.

[0004] Adsorption methods have attracted considerable attention from researchers due to their high phosphorus removal efficiency and simple operation. In recent years, researchers have increasingly focused on adsorbents made from biomass and waste materials to alleviate eutrophication. Existing patent (publication number: CN108289991A) describes a phosphorus removal adsorption microsphere, filter column, and its application in water treatment. It uses desulfurized gypsum, steel slag, bentonite, purple clay, and glutinous rice flour as raw materials to create the adsorbent packing material. After treatment with the filter column, the total phosphorus removal rate in aquaculture wastewater reaches 95.3%. A utility model patent (publication number: CN102642981A) describes a nitrogen and phosphorus removal device that uses a tower-like structure similar to a filter column. The device is filled with iron shavings, cast iron filings, or sponge iron and sulfur particles to efficiently remove nitrogen and phosphorus. A utility model patent (publication number: CN107159172A) utilizes zeolite to achieve the removal of over 90% of total nitrogen and phosphorus from wastewater. It should be noted that the nitrogen and phosphorus removal devices mentioned above all use single adsorption treatment technology. This technology has disadvantages such as being easily affected by water quality background and needing to be replaced regularly when the adsorbent is saturated.

[0005] An existing patent describes a wastewater nitrogen and phosphorus removal method and apparatus (publication number: CN104710081B) that uses an adsorption method combined with an anaerobic membrane bioreactor and an ammonia nitrogen absorption tank to remove nitrogen and phosphorus, achieving a removal rate of 99% for ammonia nitrogen and 98% for phosphorus in wastewater. This somewhat compensates for the shortcomings of the aforementioned adsorption method. However, this apparatus has the disadvantage of requiring a large footprint, making it difficult to achieve intensive integration. A utility model patent discloses a nitrogen and phosphorus removal device (publication number: CN202358991U) that combines adsorption with anaerobic tanks, anoxic tanks, and anaerobic / anoxic tanks to remove nitrogen and phosphorus, achieving good removal efficiency. However, the continuous series connection of multiple devices still makes intensive integration difficult. Therefore, developing a highly efficient, low-cost, and environmentally friendly intensive nitrogen and phosphorus removal device is a pressing technical problem to be solved in this field. Utility Model Content

[0006] This utility model provides a low-cost, combined, high-efficiency nitrogen and phosphorus removal device, which includes:

[0007] The floating bed pool has an inlet on one side and a granular base layer at the bottom. An aeration device is installed in the granular base layer. Multiple low vertical baffles of varying heights are arranged at intervals on the upper surface of the granular base layer in the direction of water flow. The top of the high baffles is close to the water surface and there is a gap between the bottom of the high baffles and the granular base layer, so that the water in the floating bed pool flows in an "S" shape.

[0008] A bio-floating bed consists of a floating bed board that is positioned above the water surface and has an adjustable height. Several hydroponic plants are placed on the floating bed board, with the roots of the hydroponic plants located in the water and the stems and leaves located above the floating bed board.

[0009] The upper partition is located above the bio-floating bed and its height is adjustable. Supplemental lighting is installed at the bottom of the upper partition.

[0010] The filter column is installed at the bottom of the upper partition plate. The filter column is connected to the filter column inlet pipe and the filter column outlet pipe at both ends. The filter column inlet pipe is connected to the water body on the other side of the floating bed pool, and the filter column outlet pipe is connected to a water pump.

[0011] Furthermore, stainless steel supports higher than the water surface are provided on both sides of the floating bed pool, and several mounting holes are provided on the stainless steel supports along the height direction; the two ends of the floating bed plate and the upper partition are installed on the stainless steel supports by pins and knobs.

[0012] Furthermore, the granular base layer is made of quartz stone, and the hydroponic plants are calamus, reeds, and canna lilies.

[0013] Furthermore, the filter column includes a shell, within which are arranged sequentially along the water flow direction: nylon mesh, quartz sand, nylon mesh, adsorbent, nylon mesh, quartz sand, and nylon mesh; the adsorbent is 100-mesh crushed gypsum board that has undergone low-temperature pyrolysis at 150℃.

[0014] Furthermore, the supplementary lighting is LED.

[0015] Furthermore, the outlet of the filter column's water outlet pipe is connected to the inlet of the floating bed pool and the external purified water receiving point via a T-junction.

[0016] The beneficial effects of this utility model are as follows:

[0017] 1) This utility model utilizes a steel frame structure to combine the bio-floating bed and filter column into a whole. On the one hand, it improves the bio-utilization performance of the floating bed, and on the other hand, combined with the filter column, it can remove phosphorus from the water in a shorter time. The device is simple to operate, has no secondary pollution, is environmentally friendly, and is intensive, making it suitable for practical application and promotion.

[0018] 2) The floating bed pool uses quartzite matrix filler as the bottom support layer and is equipped with an aeration device to provide sufficient dissolved oxygen for plant growth and metabolism, thereby further improving the nitrogen and phosphorus removal performance of the floating bed.

[0019] 3) Three sets of vertical high and low baffles are set in the floating bed tank to form an "S"-shaped baffle hydraulic channel, which increases the hydraulic residence time and improves the filtration effect;

[0020] 4) The upper part of the floating bed is equipped with an adjustable height LED light, which provides supplemental lighting for the plants, enhances their photosynthesis, shortens the biotransformation and metabolic cycle of traditional bio-floating beds, and improves bioavailability.

[0021] 5) The stainless steel frame can be adjusted in height according to the bed volume requirements, thereby enhancing operational flexibility;

[0022] 6) The main component of the pyrolyzed gypsum board is CaSO4·0.5H2O. Ca has a strong affinity for phosphate anions, and phosphorus is removed in the form of precipitates such as CaHPO4, Ca3(PO4)2 and hydroxyapatite. At the same time, the alkaline environment it creates makes the filler surface carry a large number of positive charges, which makes it have a strong electrostatic attraction to negatively charged phosphate anions.

[0023] 7) The aquatic plants and filter media used in the floating bed are made of gypsum board materials that are widely available and extremely low in cost. The recycled plants and media have reuse value, thus achieving the effect of resource utilization to a certain extent.

[0024] 8) Through the cyclical purification process of water inlet - floating bed - filter column - water outlet and then back to water inlet - floating bed..., efficient nitrogen and phosphorus removal is ensured, water quality is purified in a cycle, and the treated water can be used for agricultural irrigation, urban water use and landscape water use, etc. Attached Figure Description

[0025] To more clearly illustrate the technical solutions in the embodiments of this utility model, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0026] Figure 1 This is a structural diagram of a low-cost, combined, high-efficiency nitrogen and phosphorus removal device according to this utility model.

[0027] Figure 2 This is a diagram showing the total nitrogen removal effect in an embodiment of this utility model.

[0028] Figure 3 This is a diagram showing the effect of total phosphorus removal in an embodiment of this utility model.

[0029] In the diagram: 1. Floating biological bed; 2. Granular base layer; 3. Aeration device; 4. Filter column inlet; 5. Filter column outlet pipe; 6. Filter column inlet pipe; 7. Filter column; 8. Packing material; 9. Supplemental lighting; 10. Pin knob; 11. Baffle; 12. Floating bed plate; 13. Partition; 14. Floating bed tank; 15. Water sample inlet. Detailed Implementation

[0030] In the following description, numerous specific details are set forth in order to provide a more thorough understanding of the present invention. However, it will be apparent to those skilled in the art that the present invention can be practiced without one or more of these details. In other instances, certain technical features well-known in the art have not been described in order to avoid confusion with the present invention.

[0031] To fully understand this utility model, detailed steps and structures will be presented in the following description to illustrate the technical solution of this utility model. Preferred embodiments of this utility model are described in detail below; however, in addition to these detailed descriptions, this utility model may have other embodiments.

[0032] Reference Figure 1-3 As shown, this utility model provides a low-cost combined high-efficiency nitrogen and phosphorus removal device, which mainly includes a floating bed pool 14, a biological floating bed 1, an upper baffle 13, and a filter column 7.

[0033] Floating bed pool 14

[0034] A water inlet is provided on one side of the floating bed pool 14. A granular base layer 2 is laid at the bottom of the floating bed pool 14, and an aeration device 3 is installed within the granular base layer 2. Multiple baffles 11 are arranged on the upper surface of the granular base layer 2 in the direction of water flow. The baffles 11 consist of staggered high baffles 11-1 and low baffles 11-2. The high baffles 11-1 are higher than the low baffles 11-2, and the top of the high baffles 11-1 is close to the water surface, while the bottom has a gap with the granular base layer 2, forcing the water in the floating bed pool 14 to flow in an "S" shape. The water to be treated for nitrogen and phosphorus removal enters the floating bed pool 14 through the water inlet. The water flows slowly in an S-shape within the floating bed pool 14, increasing the contact time between the water flow and the biological floating bed and granular base layer, which is beneficial for the absorption by plant roots and microbial degradation of the biological floating bed, and also improves the adsorption efficiency of the granular base layer. The vertical baffles 11, with their varying heights, not only alter the water flow direction but also create turbulence, further enhancing the interaction between the water flow and the biological floating bed and granular substrate. Furthermore, the aeration device 3 increases the dissolved oxygen content within the floating bed tank, promoting microbial growth and degradation. Simultaneously, aeration also acts as a mixer, ensuring a more even distribution of pollutants within the floating bed tank and improving treatment efficiency.

[0035] In an optional embodiment, stainless steel supports higher than the water surface are provided on both sides of the floating bed pool 14. Several mounting holes are provided on the stainless steel supports along the height direction. The two ends of the floating bed plate 12 and the upper partition plate 13 are respectively mounted on the stainless steel supports by the pin knob 10. In addition, the installation height of the floating bed plate 12 and the upper partition plate 13 can be freely adjusted by the mounting holes of different heights.

[0036] In one optional embodiment, the granular base layer 2 is quartz stone. Depending on actual needs, other types of granular base layer 2 can also be used, such as volcanic rock, pebbles, etc.

[0037] Bio-floating bed 1

[0038] The bio-floating bed 1 includes a floating bed plate 12 that is positioned above the water surface and has an adjustable height. Several hydroponic plants are placed on the floating bed plate 12, with the roots of the hydroponic plants located in the water and the stems and leaves above the floating bed plate 12. The aquatic plants absorb nutrients such as nitrogen and phosphorus from the water through their roots, while the microbial community around the roots also degrades some organic matter and nitrogen compounds.

[0039] Preferably, hydroponic plants include sweet flag, reeds, and canna lilies. These plants have strong root absorption capacity and pollution tolerance, enabling them to grow in polluted water and effectively remove pollutants such as nitrogen and phosphorus. The height of the floating bed plate 12 is adjustable, allowing for adjustments based on different seasons, light conditions, and plant growth to ensure optimal plant growth and thus improve nitrogen and phosphorus removal efficiency.

[0040] Upper partition 13

[0041] The upper partition 13 is located above the bio-floating bed 1 and its height is adjustable. A supplemental light 9 is provided at the bottom of the upper partition 13. In an optional embodiment, the supplemental light 9 at the bottom of the upper partition 13 is an LED light. The supplemental light 9 is mainly used to compensate for insufficient natural light, ensuring that hydroponic plants can still carry out normal photosynthesis even in low light conditions, thereby maintaining their nitrogen and phosphorus removal efficiency. By adjusting the brightness and illumination time of the LED light, the plant growth environment can be further optimized, improving the overall efficiency of the nitrogen and phosphorus removal device.

[0042] Filter column 7

[0043] The filter column 7 is installed at the bottom of the upper partition 13. The bottom and top of the filter column 7 are connected to the filter column inlet pipe 6 and the filter column outlet pipe 5, respectively. The filter column inlet 4 of the filter column inlet pipe 6 is connected to the water body on the other side of the floating bed pool 14. The filter column outlet pipe 5 is connected to a water pump, which draws water from the floating bed pool 14 and outputs it after multiple filtrations by the filter column 7. The outlet of the filter column outlet pipe 5 is connected to the inlet of the floating bed pool 14 and an external purified water receiving point via a T-junction. Both outlets of the T-junction are equipped with solenoid valves to control the connection between the inlet of the floating bed pool 14 and the external purified water receiving point. After the water is purified, it can be directly delivered to the external purified water receiving point; if the water quality does not meet the standards, the water discharged from the filter column outlet pipe 5 re-enters the floating bed pool 14 through the water sample inlet 15.

[0044] The filter column 7 is filled with low-temperature pyrolytic gypsum board material 8 as an adsorbent. This material is prepared by crushing and sieving gypsum board raw materials to 100 mesh, followed by low-temperature pyrolysis in a tube furnace at 150℃, resulting in low cost. The filter column 7 has a nylon mesh at the bottom, followed by a layer of quartz sand, then another layer of nylon mesh, and finally another layer of quartz sand, forming a filling pattern of "nylon mesh-quartz sand-nylon mesh-adsorbent-nylon mesh-quartz sand-nylon mesh".

[0045] The water to be treated flows into the floating bed tank 14 through the water sample inlet 15. After preliminary treatment by the biological floating bed and granular base layer in the floating bed tank 14, pollutants such as nitrogen and phosphorus in the water are effectively reduced. Subsequently, the water enters the filter column 7 through the filter column inlet pipe for further deep treatment, with a flow rate set at 1 mL / min, and finally flows out through the filter column outlet pipe 5, completing one purification process. The influent water sample to the floating bed tank 14 is prepared based on the actual water body to achieve a total nitrogen concentration of 10 mg / L and a total phosphorus concentration of 2 mg / L to meet the reuse requirements.

[0046] The filtration process of the nitrogen and phosphorus removal device described above is as follows:

[0047] Adsorbent preparation: Dry the gypsum board raw material, crush it and pass it through a 100-mesh sieve. Pyrolyze the sieved gypsum board powder in a tube furnace, raise the temperature to 150°C at a rate of 5°C / min, pyrolyze at 150°C for 2 hours, and then cool it to room temperature to obtain the adsorbent material.

[0048] like Figure 1 As shown, a baffle 11 is installed in a floating bed tank 14 with dimensions of 40cm×24cm×25cm to make the water flow in an "S" shape. The water to be treated enters the floating bed tank through the water sample inlet 15, and the hydraulic retention time is set to 2 days. Afterward, the water enters the filter column 7 through the filter column inlet 4 and filter column inlet pipe 6. The filter column has a packing bed volume of 80mL, with a certain mass of quartz sand filled at the top and bottom of the packing material, and nylon mesh is used to trap large particles, forming a filling pattern of "nylon mesh, quartz sand, nylon mesh, adsorbent, nylon mesh, quartz sand, nylon mesh," with a hydraulic retention time of 10 minutes. The final effluent from the filter column re-enters the tank through the floating bed inlet for a second circulation.

[0049] The aeration device 3 in the floating bed pool provides sufficient dissolved oxygen to ensure the growth and development of plant roots and improve the metabolic activity of root microorganisms. The height of the floating bed plate 12 is adjusted by the pin knob 10 to match the bed volume of the floating bed pool. At the same time, the height of the partition 13 is adjusted and the LED lights 9 are turned on to provide supplemental lighting for the plants on the floating bed.

[0050] After the device is operational, water samples are taken after each cycle to determine total nitrogen and total phosphorus. For example... Figure 2 and Figure 3As shown, after the first cycle, the total nitrogen concentration decreased from the initial 10.36 mg / L to 2.11 mg / L, achieving a removal rate of 79.63%; the total phosphorus concentration decreased from the initial 2.17 mg / L to 0.29 mg / L, achieving a removal rate of 90.5%. After the second cycle, the total nitrogen concentration decreased to 0.88 mg / L, achieving a removal rate of 91.51% compared to the initial concentration, and the total phosphorus concentration decreased to 0.11 mg / L, achieving a removal rate of 94.93% compared to the initial concentration. At this point, both total nitrogen and total phosphorus meet the Class II water standard.

[0051] In summary, this embodiment constructs a highly efficient, low-cost, and environmentally friendly device for nitrogen and phosphorus removal using a combination of a bio-floating bed and a filter column.

[0052] The preferred embodiments of this utility model have been described above. It should be understood that this utility model is not limited to the specific embodiments described above. Devices and structures not described in detail herein should be understood as being implemented in a conventional manner within the art. Any person skilled in the art can make many possible variations and modifications to the technical solutions of this utility model using the disclosed methods and techniques, or modify them into equivalent embodiments with equivalent changes, without departing from the scope of the technical solution of this utility model. This does not affect the essential content of this utility model. Therefore, any simple modifications, equivalent changes, and modifications made to the above embodiments based on the technical essence of this utility model, without departing from the content of the technical solution of this utility model, still fall within the protection scope of the technical solution of this utility model.

Claims

1. A low-cost combined high-efficiency denitrification and dephosphorization device, characterized in that, The nitrogen and phosphorus removal device includes: A floating bed pool (14) is provided with an inlet on one side. A granular base layer (2) is laid at the bottom of the floating bed pool (14). An aeration device (3) is installed in the granular base layer (2). Multiple low vertical baffles of different heights are arranged sequentially on the upper surface of the granular base layer (2) in the direction of water flow. The top of the high baffle (11-1) is close to the water surface and there is a gap between the bottom and the granular base layer (2), so that the water in the floating bed pool (14) flows in an "S" shape. Biological floating bed (1), the biological floating bed (1) includes a floating bed plate (12) that is set above the water surface and is height adjustable, and a number of hydroponic plants are set on the floating bed plate (12), the roots of the hydroponic plants are in the water, and the stems and leaves are above the floating bed plate (12); The upper partition (13) is located above the bio-floating bed (1) and its height is adjustable. A supplementary light (9) is provided at the bottom of the upper partition (13). The filter column (7) is installed at the bottom of the upper partition (13). The filter column (7) is connected to the filter column inlet pipe and the filter column outlet pipe at both ends respectively. The filter column inlet pipe is connected to the water body on the other side of the floating bed pool (14), and the filter column outlet pipe is connected to a water pump.

2. A low-cost combined high-efficiency denitrification and dephosphorization device according to claim 1, characterized in that, Stainless steel supports higher than the water surface are provided on both sides of the floating bed pool (14), and several mounting holes are provided on the stainless steel supports along the height direction. The two ends of the floating bed plate (12) and the upper partition plate (13) are mounted on the stainless steel bracket by means of pins and knobs.

3. A low cost combined high efficiency denitrification and dephosphorization device according to claim 1, characterized in that, The granular base layer (2) is made of quartz stone, and the hydroponic plants are calamus, reeds and canna lilies.

4. A low cost combined high efficiency denitrification and dephosphorization device according to claim 1, characterized in that, The filter column (7) includes a shell, and inside the shell, in the direction of water flow, there are nylon mesh, quartz sand, nylon mesh, adsorbent, nylon mesh, quartz sand, and nylon mesh arranged in sequence; The adsorbent is 100-mesh crushed gypsum board that has undergone low-temperature pyrolysis at 150℃.

5. A low cost combined high efficiency denitrification and dephosphorization device according to claim 1, characterized in that, The supplementary light (9) is an LED light.

6. A low cost combined high efficiency denitrification and dephosphorization device according to claim 1, characterized in that, The outlet of the filter column outlet pipe is connected to the inlet of the floating bed pool (14) and the external clean water receiving point through a T-junction.

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