A preliminary rainwater purification system applied to open water body

Abstract

The present application relates to a kind of initial rainwater purification systems applied to open water body, from the upstream side of raw water to downstream side in turn including ecological filter dam subsystem, anoxic biochemical subsystem and aerobic biochemical subsystem;The ecological filter dam upstream dam body is filled with Bing stone cage net and its inside filler, several micro-nano aeration equipment are arranged in the filler interior;The ecological filter dam main purification area is filled with granular filler and slow-release carbon source, and the upper portion is planted with emergent plants;The anoxic biochemical subsystem includes anoxic biochemical tank, and microbial layer and biological membrane filler are arranged in the anoxic biochemical tank;The aerobic biochemical subsystem includes aerobic biochemical tank, and microbial layer and biological membrane filler are arranged in the aerobic biochemical tank.The present application improves the biodegradability of raw water, intercepts suspended solids and floating objects carried into river and lake by initial rainwater, adsorbs and degrades dissolved substances, and is of great significance to initial rainwater pollution control into river.

Description

Technical Field

[0001] This invention relates to an initial rainwater purification system for open water bodies, belonging to the technical field of ecological wastewater purification. Background Technology

[0002] In recent years, with the country's emphasis and in-depth research, point source pollution in my country has been gradually and effectively controlled. In many places, non-point source pollution in watersheds is rising from a secondary issue to a primary one. Urban non-point source pollution caused by initial rainwater runoff and combined sewer overflows has become a significant factor restricting the improvement of urban water quality. Because the spatial and temporal distribution, pollutant concentration, and total amount of initial rainwater pollution are highly random, it is difficult to treat and purify it before it enters open water bodies. Therefore, it is essential to install relevant treatment facilities in rivers and lakes to purify pollution caused by initial rainwater and maintain stable water quality.

[0003] Generally, initial rainwater contains high levels of suspended solids, ammonia nitrogen, and total phosphorus, and has poor biodegradability. Therefore, its treatment must consider not only the removal of dissolved pollutants but also the interception of suspended solids and the improvement of biodegradability. Currently, purification measures applied to open water bodies mainly include the deployment of ecological floating beds, the addition of microbial agents, and biofilm remediation technology. However, these measures are insufficient to address the problem of low biodegradability of incoming water. For example, invention patent CN 110127940B proposes a water environment ecological restoration system for purifying wastewater entering rivers and lakes, but this system is ineffective in efficiently treating initial rainwater with poor biodegradability. Summary of the Invention

[0004] To address the aforementioned problems, this invention discloses an initial rainwater purification system for open water bodies. This system combines physical, chemical, and biological purification technologies to improve the biodegradability of incoming water, intercept suspended and floating matter carried into rivers and lakes by initial rainwater, and adsorb and degrade dissolved substances. This is of great significance for controlling pollution from initial rainwater entering rivers. The specific technical solution is as follows:

[0005] An initial rainwater purification system for open water bodies includes, from upstream to downstream, an ecological filter dam system, an anoxic biochemical subsystem, and an aerobic biochemical subsystem.

[0006] The ecological filter dam subsystem includes an upstream dam body and a main purification area. The upstream dam body faces the upstream water and is sloping. The main purification area is located on the downstream side of the upstream dam body and is rectangular in shape, connected to the back of the upstream dam body.

[0007] The upstream dam body of the ecological filter dam is filled with gabion mesh and its internal filler material, and several micro-nano aeration devices are arranged inside the filler material.

[0008] The main purification area of ​​the ecological filter dam is filled with granular filler and slow-release carbon source, and emergent plants are planted on its upper part.

[0009] The anoxic biochemical subsystem includes an anoxic biochemical tank, in which a microbial layer and granular packing material are arranged.

[0010] The aerobic biochemical subsystem includes an aerobic biochemical tank, in which a microbial layer and granular packing material are arranged.

[0011] Furthermore, the micro-nano aeration device is connected to a solar power generation system, which is fixed above the main purification area of ​​the ecological filter dam.

[0012] Furthermore, the slope inclination angle of the upstream dam body of the ecological filter dam is 20-30°.

[0013] Furthermore, the upstream dam body of the ecological filter dam is filled with one or more combinations of heavy stones, metal blocks, gravel, and graded pebbles, and micro-nano aeration heads are evenly distributed in the gaps between the filling materials. The micro-nano aeration heads have a pore size of 100μm and a density of 1-2 heads / m. 3 Each micro-nano aeration head has an aeration rate of 6-10 L / min, which increases the dissolved oxygen in the water by 0.4-1.2 mg / L when the oxygen utilization rate of the microporous aeration head is 20%.

[0014] Furthermore, the granular filler in the main purification area of ​​the ecological filter dam is one or more of gravel, ceramsite, zeolite, volcanic rock, and limestone, and the slow-release carbon source is one or more of biodegradable PHB, PHBV, and PHAs, which are uniformly filled between the granular filler.

[0015] Furthermore, the emergent plants planted above the main purification area of ​​the ecological filter dam are one or more combinations of canna lilies, calamus, loosestrife, iris, windmill grass, cattail, and reeds.

[0016] Furthermore, the microbial layer of the anoxic biochemical subsystem is laid at the bottom of the anoxic biochemical pool. It is a microbial carrier prepared using polyvinyl alcohol-sodium alginate composite fixation technology. On top of it are one or more combinations of gravel, ceramsite, zeolite, volcanic rock, and limestone placed in a metal mesh, and composite heavy stone blocks and / or metal blocks.

[0017] The microbial carrier preparation process for the microbial layer of the anoxic biochemical subsystem is as follows: Polyvinyl alcohol, sodium alginate, and distilled water are mixed and stirred at 90°C to dissolve. The mixture is then cooled and kept at 30-40°C in a water bath. Activated carbon powder is added and stirred for 1 hour, then cooled to room temperature. An appropriate concentration of denitrifying polyphosphate-accumulating bacteria suspension is added and stirred evenly before being poured into a mold. The mold is then frozen and thawed three times to solidify the material. Finally, the mixture is cross-linked for 1 hour each in a 2% CaCl2 saturated boric acid solution and a 0.5 mol / L NaSO4 solution. The resulting microbial carrier contains approximately 5% polyvinyl alcohol, 2% sodium alginate, and 1% activated carbon.

[0018] In the early stages of system operation, before a stable microbial community has formed in the system, the microorganisms in the microbial layer purify the incoming water to ensure the initial purification effect. After a period of operation, a stable microbial community has formed in the system, so there is no need to replenish or replace the microbial layer.

[0019] Furthermore, the microbial layer of the aerobic biochemical subsystem is laid at the bottom of the aerobic biochemical tank. It is a microbial carrier prepared by cross-linking method using polyvinyl alcohol-sodium alginate composite fixation technology. Several micro-nano aeration devices are also arranged inside it. A perforated plate is arranged above it. The perforated plate is equipped with suspended packing material, which includes one or more of biological rope packing material, combined packing material, and elastic packing material. Heavy stones and / or metal blocks are attached below the suspended packing material.

[0020] The microbial carrier preparation process for the microbial layer of the aerobic biochemical subsystem is as follows: Polyvinyl alcohol, sodium alginate, and distilled water are mixed and dissolved by stirring at 90°C. The mixture is then cooled and kept at 30-40°C in a water bath. Activated carbon powder is added and stirred for 1 hour, then cooled to room temperature. An appropriate concentration of nitrifying bacteria suspension is added and stirred evenly before being poured into a mold. The mold is then frozen and thawed three times to solidify the mixture. Finally, the mixture is cross-linked for 1 hour each in a 2% CaCl2 saturated boric acid solution and a 0.5 mol / L NaSO4 solution. The prepared microbial carrier contains approximately 10% polyvinyl alcohol, approximately 2% sodium alginate, and approximately 1% activated carbon.

[0021] Furthermore, in the aerobic biochemical subsystem, the packing material, pebbles, and micro / nano aerators are arranged within a 2m area above the microbial layer. The micro / nano aerators have a pore size of 100μm and are arranged at a density of 2-4 per m. 3 Each micro-nano aeration head has an aeration rate of 6-10 L / min, resulting in a dissolved oxygen level of approximately 3 mg / L in the bottom area of ​​the aerobic biochemical subsystem when the oxygen utilization rate of the microporous aeration head is 20%.

[0022] The beneficial effects of this invention are:

[0023] This invention combines physical, chemical, and biological treatment measures, utilizing the adsorption, absorption, and degradation effects of composite fillers, plants, and microorganisms, supplemented by aeration, slow release, and microbial immobilization technologies to achieve comprehensive and long-term removal of solid and dissolved pollutants from initial rainwater. In this invention, the upstream dam of the ecological filter dam intercepts floating matter carried by initial rainwater, accelerating the sedimentation of suspended solids in the incoming water. Micro-nano aeration equipment deployed inside the upstream dam increases the dissolved oxygen content in the incoming water, effectively removing COD and improving the biodegradability of the water to a certain extent. The solar power system stores solar energy in battery banks on sunny days, converting it into AC power using an inverter to support the operation of the micro-nano aeration equipment, resulting in energy conservation and environmental protection. The gravel, ceramsite, volcanic rock, and zeolite filling the main purification zone of the ecological filter dam have good adsorption effects and large specific surface areas, efficiently adsorbing a portion of NH4. + -N and TP provide a good growth and attachment carrier for microorganisms; the slow-release carbon source uniformly filled in the main purification area of ​​the ecological filter dam is decomposed into small molecule organic matter by microorganisms and then utilized as a carbon source, improving the biodegradability and denitrification effect of the water; emergent plants planted above the main purification area of ​​the ecological filter dam absorb NH4 in the water. + -N and TP, while also having good landscape effects; the microbial layer below the anoxic and aerobic biochemical subsystems can realize microbial fixation and pollutant degradation, ensuring the purification effect when a stable microbial community has not yet formed in the system in the early stage of operation. Attached Figure Description

[0024] Figure 1 This is a schematic diagram of the structure of the present invention.

[0025] List of reference numerals: 100—Ecological filter dam subsystem, 200—Anoxic biochemical subsystem, 300—Aerobic biochemical subsystem, 110—Upstream dam body of the ecological filter dam system, 120—Main purification zone of the ecological filter dam system, 111—Stones and pebbles, 112—Micro-nano aeration heads, 121—Solar power generation system, 122—Removable cage frame, 123—Ceramic granules, volcanic rock, and limestone filler, 124—Slow-release carbon source, 125—Emerging plants, 2 01—Microbial layer of the anoxic biochemical subsystem; 202—Gravel and ceramsite packing material; 203—Pebble of the anoxic biochemical subsystem; 204—Metal mesh of the anoxic biochemical subsystem; 301—Microbial layer of the aerobic biochemical subsystem; 302—Gravel and ceramsite packing material; 3203—Pebble of the aerobic biochemical subsystem; 304—Metal mesh of the aerobic biochemical subsystem; 305—Micro-nano aeration equipment; 306—Perforated plate; 307—Bio-rope packing material; 308—Metal block.

[0026] Figure 2 This is a flowchart of the polyvinyl alcohol-sodium alginate composite microbial immobilization process in an embodiment of the present invention. Detailed Implementation

[0027] The present invention will be further illustrated below with reference to the accompanying drawings and specific embodiments. It should be understood that the following specific embodiments are for illustrative purposes only and are not intended to limit the scope of the invention.

[0028] Combined with appendix Figure 1 As can be seen, the structure involved in this invention includes: an ecological filter dam system 100, an anoxic biochemical subsystem 200, an aerobic biochemical subsystem 300, an upstream dam body 110 of the ecological filter dam system, a main purification zone 120 of the ecological filter dam system, stones and pebbles 111, micro-nano aeration heads 112, a solar power generation system 121, a detachable cage frame 122, ceramsite, volcanic rock and limestone filler 123, a slow-release carbon source 124, emergent plants 125, a microbial layer 201 of the anoxic biochemical subsystem, gravel and ceramsite filler 202, pebbles 203 of the anoxic biochemical subsystem, a metal mesh 204 of the anoxic biochemical subsystem, a microbial layer 301 of the aerobic biochemical subsystem, gravel and ceramsite filler 302, pebbles 303 of the aerobic biochemical subsystem, a metal mesh 304 of the aerobic biochemical subsystem, micro-nano aeration equipment 305, a perforated plate 306, a biological rope filler 307, and a metal block 308.

[0029] The following describes the layout structure of this patent: An initial rainwater purification system applied to open water bodies in this embodiment includes an ecological filter dam subsystem 100, an anoxic biochemical subsystem 200 and an aerobic biochemical subsystem 300, wherein the ecological filter dam subsystem includes an upstream dam body 110 and a main purification zone 120 of the ecological filter dam subsystem.

[0030] In this embodiment, the upstream dam body 110 of the ecological filter dam system has an inclination angle of 30° to prevent the incoming water from having an excessive impact on the system, while intercepting floating objects in the incoming water and promoting the sedimentation of particulate matter.

[0031] The upstream dam body of the ecological filter dam system is filled with large stones and pebbles 111 with a particle size of 20-500mm. Micro-nano aeration heads 112 are evenly distributed in the gaps between the stones and pebbles, and connected to the solar power generation system 121 above the main purification zone 120. The micro-nano aeration heads have a pore size of 100μm and a density of 1-2 heads / m. 3 Each micro-nano aeration head has an aeration rate of 6-10 L / min. This density and intensity of aeration will not impose too much burden on engineering costs and operation. However, with an oxygen utilization rate of 20% for the microporous aeration head, it can increase the dissolved oxygen in the water of the system by 0.4-1.2 mg / L, reduce the COD of the incoming water, and improve biodegradability.

[0032] The solar power generation system 121 includes solar panels, a solar controller, a battery bank, and an inverter. The solar panels are used to collect solar energy and convert it into electrical energy, the controller is used to control charging and discharging, the battery bank is used to store the collected energy, and the inverter is used to convert direct current into alternating current.

[0033] The lower part of the main purification zone 120 of the ecological filter dam system is a detachable cage 122, which is filled with 5-50mm ceramsite, volcanic rock and a small amount of limestone. PHBV is evenly added between the fillers as a slow-release carbon source 124. PHBV can exist stably in the water for a long time. Under the action of microorganisms, it is decomposed into small molecule organic matter, which is then used by microorganisms as a carbon source to improve the biodegradability of the incoming water and increase the denitrification rate. The cage is replaced and cleaned every 1-3 months.

[0034] The upper part of the main purification area of ​​the ecological filter dam is planted with canna lilies and calamus. The plants absorb nitrogen and phosphorus compounds in the water and beautify the landscape. The planted plants need to be a certain distance from the solar power generation system 121 to avoid the plants blocking the sunlight and affecting the solar power generation system to obtain energy.

[0035] Below the anoxic biochemical subsystem 200 is the microbial layer. The microbial carriers laid on it are made using a polyvinyl alcohol-sodium alginate composite immobilization technology and a cross-linking method. The production process is as follows: polyvinyl alcohol, sodium alginate, and distilled water are mixed and stirred at 90°C to dissolve. The solution is cooled and maintained at 30-40°C in a water bath. Activated carbon powder is then added and stirred for 1 hour, followed by cooling to room temperature. An appropriate concentration of denitrifying polyphosphate-accumulating bacteria suspension is added and stirred evenly. The mixture is then poured into a mold and subjected to three freeze-thaw cycles to solidify. Finally, it is cross-linked for 1 hour each in a 2% CaCl2 saturated boric acid solution and a 0.5 mol / L NaSO4 solution. The resulting microbial carriers contain approximately 5% polyvinyl alcohol, 2% sodium alginate, and 1% activated carbon. The immobilization technology uses economical and environmentally friendly materials that do not cause secondary pollution. The microbial carriers produced by this method have good performance and the bacteria are not easily lost. In the early stages of system operation, before a stable microbial community has formed in the system, the system mainly relies on the microorganisms in the microbial layer to purify the incoming water and ensure the initial purification effect. After a period of operation, a stable microbial community has formed in the system, so there is no need to replenish or replace the microbial layer.

[0036] Gravel and ceramsite 202 are laid on top of the microbial layer. Since the filler is light and easily floats on the water surface, the filler is combined with pebbles 203 and placed in a metal mesh.

[0037] Below the aerobic biochemical subsystem 300 is the microbial layer. The microbial carriers are fabricated using a polyvinyl alcohol-sodium alginate composite immobilization technology and a cross-linking method. The fabrication process involves mixing polyvinyl alcohol, sodium alginate, and distilled water, stirring and dissolving at 90°C, cooling, and maintaining the solution temperature at 30-40°C in a water bath. Activated carbon powder is then added and stirred for 1 hour, followed by cooling to room temperature. An appropriate concentration of nitrifying bacteria suspension is added and stirred evenly before being poured into a mold. The mold is then subjected to three freeze-thaw cycles to solidify its shape. Finally, it is cross-linked for 1 hour each in a 2% CaCl2 saturated boric acid solution and a 0.5 mol / L NaSO4 solution. The resulting microbial carriers contain approximately 10% polyvinyl alcohol, 2% sodium alginate, and 1% activated carbon.

[0038] Gravel and ceramsite 302 are laid on the microbial layer 301. Since the filler is light and easily floats on the water surface, the filler and pebbles 303 are combined and placed in a metal mesh 304, and micro-nano aeration heads 305 are evenly distributed. The micro-nano aeration equipment is connected to a solar power generation system for power supply.

[0039] In this embodiment, the packing material, pebbles, and micro / nano aerators in the aerobic biochemical subsystem are arranged within a 2m area above the microbial layer. The micro / nano aerators have a pore size of 100μm and are arranged at a density of 2-4 per m. 3 Each micro-nano aeration head has an aeration rate of 6-10 L / min, which results in a dissolved oxygen level of approximately 3 mg / L in the bottom area of ​​the aerobic biochemical subsystem when the oxygen utilization rate of the microporous aeration head is 20%. At this dissolved oxygen concentration, nitrifying bacteria can achieve a good pollutant purification effect.

[0040] The upper part of the aerobic biochemical subsystem is equipped with an orifice plate 306, on which a biological rope 307 is suspended. To prevent the biological rope from tangling under the action of water flow, a metal block 308 is attached to its bottom.

[0041] The term "connection" as used in this application can mean a direct connection between components or an indirect connection between components through other components.

[0042] Based on the above-described preferred embodiments of the present invention, and through the foregoing description, those skilled in the art can make various changes and modifications without departing from the inventive concept. The technical scope of this invention is not limited to the contents of the specification, but must be determined according to the scope of the claims.

Claims

1. A primary rainwater purification system for open water bodies, characterized in that, From upstream to downstream, the system includes an ecological filter dam system, anoxic biochemical subsystem, and aerobic biochemical subsystem. The ecological filter dam subsystem includes an upstream dam body and a main purification area. The upstream dam body faces the upstream water and is sloping. The main purification area is located on the downstream side of the upstream dam body and is rectangular in shape, connected to the back of the upstream dam body. The upstream dam body of the ecological filter dam is filled with gabion mesh and its internal filler material, and several micro-nano aeration devices are arranged inside the filler material; micro-nano aeration heads are evenly distributed in the gaps of the filler material of the upstream dam body of the ecological filter dam, which increases the dissolved oxygen in the water by 0.4-1.2 mg / L when the oxygen utilization rate of the microporous aeration head is 20%. The main purification area of ​​the ecological filter dam is filled with granular filler and slow-release carbon source, and emergent plants are planted on its upper part. The anoxic biochemical subsystem includes an anoxic biochemical tank, in which a microbial layer and granular packing material are arranged. The microbial layer of the anoxic biochemical subsystem is laid at the bottom of the anoxic biochemical tank and is a microbial carrier prepared using polyvinyl alcohol-sodium alginate composite immobilization technology. On top of it are one or more combinations of gravel, ceramsite, zeolite, volcanic rock, and limestone placed in a metal mesh, and combined with heavy stone blocks and / or metal blocks. The microbial carrier has a polyvinyl alcohol content of 5%, a sodium alginate content of 2%, and an activated carbon content of 1%. The aerobic biochemical subsystem includes an aerobic biochemical tank, in which a microbial layer and granular packing are arranged. The microbial layer of the aerobic biochemical subsystem is laid at the bottom of the aerobic biochemical tank. It is a microbial carrier prepared by cross-linking method using polyvinyl alcohol-sodium alginate composite fixation technology. Several micro-nano aeration devices are also arranged inside it. A perforated plate is arranged above it. The perforated plate is equipped with suspended packing, which includes one or more of biological rope packing, combined packing, and elastic packing. Heavy stones and / or metal blocks are attached below the suspended packing. The microbial carrier has a polyvinyl alcohol content of 10%, a sodium alginate content of 2%, and an activated carbon content of 1%.

2. The initial rainwater purification system for open water bodies according to claim 1, characterized in that, The micro-nano aeration device is connected to a solar power generation system, which is fixed above the main purification area of ​​the ecological filter dam.

3. The initial rainwater purification system for open water bodies according to claim 1, characterized in that, The slope inclination angle of the upstream dam body of the ecological filter dam is 20-30°.

4. The initial rainwater purification system for open water bodies according to claim 1, characterized in that, The upstream dam body of the ecological filter dam is filled with one or more combinations of heavy stones, metal blocks, gravel, and graded pebbles. The micro-nano aeration heads have a pore size of 100μm and are arranged at a density of 1-2 per m. 3 Each micro-nano aeration head has an aeration rate of 6-10 L / min.

5. The initial rainwater purification system for open water bodies according to claim 1, characterized in that, The granular filler material in the main purification area of ​​the ecological filter dam is one or more of gravel, ceramsite, zeolite, volcanic rock, and limestone, and the slow-release carbon source is one or more of biodegradable PHB, PHBV, and PHAs, which are uniformly filled between the granular filler materials.

6. The initial rainwater purification system for open water bodies according to claim 1, characterized in that, The emergent plants planted above the main purification area of ​​the ecological filter dam are one or more combinations of canna lilies, calamus, loosestrife, iris, windmill grass, cattail, and reeds.

7. The initial rainwater purification system for open water bodies according to claim 1, characterized in that... ， The microbial carrier preparation process of the microbial layer of the anoxic biochemical subsystem is as follows: Polyvinyl alcohol, sodium alginate and distilled water are mixed and stirred at 90 °C to dissolve. The mixture is cooled and the solution temperature is maintained at 30-40 °C in a water bath. Activated carbon powder is added and stirred for 1 hour. The mixture is then cooled to room temperature. An appropriate concentration of denitrifying polyphosphate suspension is added and stirred evenly. The mixture is then poured into a mold and placed in a refrigerator for repeated freeze-thaw cycles 3 times to form the shape. The mixture is then crosslinked in 2% CaCl2 saturated boric acid solution and 0.5 mol / L NaSO4 solution for 1 hour each. In the early stages of system operation, before a stable microbial community has formed in the system, the microorganisms in the microbial layer purify the incoming water to ensure the initial purification effect. After a period of operation, a stable microbial community has formed in the system, so there is no need to replenish or replace the microbial layer.

8. The initial rainwater purification system for open water bodies according to claim 1, characterized in that, The microbial carrier preparation process of the aerobic biochemical subsystem microbial layer is as follows: polyvinyl alcohol, sodium alginate and distilled water are mixed and stirred at 90 °C to dissolve. After cooling, the solution temperature is maintained at 30-40 °C in a water bath. Activated carbon powder is added and stirred for 1 hour. After cooling to room temperature, an appropriate concentration of nitrifying bacteria suspension is added and stirred evenly. The mixture is then poured into a mold and placed in a refrigerator for repeated freeze-thaw cycles 3 times to form the shape. The mixture is then crosslinked in 2% CaCl2 saturated boric acid solution and 0.5 mol / L NaSO4 solution for 1 hour each.

9. The initial rainwater purification system for open water bodies according to claim 1, characterized in that, The packing material, pebbles, and micro / nano aerators in the aerobic biochemical subsystem are arranged within a 2 m area above the microbial layer. The micro / nano aerators have a pore size of 100 μm and are arranged at a density of 2-4 per m. 3 Each micro-nano aeration head has an aeration rate of 6-10 L / min, which results in a dissolved oxygen level of approximately 3 mg / L in the bottom area of ​​the aerobic biochemical subsystem when the oxygen utilization rate of the microporous aeration head is 20%.

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