CN210737723U - Rainwater purification and reuse bioretention system - Google Patents

Abstract

The utility model discloses a rainwater purification and reuse biological retention system. The system includes a rain garden and a landscape fountain, wherein the rain garden includes a vegetation layer, a covering layer, a filling layer, a geotextile layer, a supporting layer and a drainage layer in order from top to bottom. Plants are planted in the filling layer, and the filling layer includes soil, River sand, peat soil, zeolite, vermiculite and residual sludge from water plants; the fountain pool of the landscape fountain, the fountain pool is provided with a disinfection layer, a water storage layer and a fountain layer from bottom to top, and a sedimentation tank is provided at the bottom of the fountain pool; disinfection UV lamp tube is provided in the upper layer, and the disinfection layer is connected with the drainage layer, and the fountain pool and the filler layer form a connector structure; the submersible pump in the water storage layer supplies the water in the water storage layer to the fountain water pipe and sprays it out in the fountain layer . The system can provide a good environment for plant growth and effectively remove pollutants in rainwater runoff, and the rainwater can be used as landscape fountain water after purification, which can supplement urban landscape water and reduce the pressure of municipal drainage.

Description

Rainwater purification and reuse bioretention system

technical field

The utility model belongs to the field of sponge city construction, in particular to a rainwater purification and reuse bioretention system.

Background technique

The rapid development of urbanization has directly changed the nature and morphological characteristics of the underlying surface, aggravated the pollution of rainfall runoff, and carried a large amount of pollutants (suspended solids, nitrogen, phosphorus, etc.) in the runoff, thus causing a series of urban water environment. The problems of eutrophication and black odor in urban rivers are particularly prominent. A bioretention facility is a widely used low-impact development facility that can effectively reduce and control the migration of runoff pollutants from the source. Remove runoff pollutants to achieve the function of purifying water quality. Among them, filler is a key factor in purifying water quality, which not only provides a good environment for plant growth, but also provides an adaptive environment for the growth and reproduction of microorganisms. The components in the filler can also directly remove pollutants in runoff through physical and chemical action. At present, most bioretention facilities are divided into cover layer, planting soil layer, geotextile layer, filler layer, geotextile layer, support layer and drainage layer. There are many layers and high operation and maintenance costs; The effluent is limited by the maximum dynamic water level of the groundwater from the bottom of the facility to be greater than 1m. Generally, direct infiltration is not allowed, and it needs to be collected and discharged into the municipal drainage pipe network. Therefore, the bioretention facility still needs to be further improved.

Utility model content

The utility model aims to solve one of the technical problems in the related art at least to a certain extent.

The utility model is completed based on the following concepts: on the one hand, the composition and proportion of the filler are adjusted, and the planting soil layer and the filler layer are combined into one, so as to reduce the operation and operation and maintenance costs of the bioretention facilities; on the other hand, the use of bioretention The facility removes a variety of pollutants in the runoff, and the effluent from the bioretention facility undergoes ultraviolet disinfection treatment and reuses it as landscape water. Landscape water is an important part of the modern urban water environment. The state stipulates that the supplement of landscape water cannot use tap water or groundwater The use of effluent from bioretention facilities as supplementary water for landscape water can not only improve the comprehensive benefits of facilities, but also alleviate the difficulty of supplementing urban landscape water sources in my country and reduce the pressure on municipal drainage.

Therefore, one purpose of the present invention is to propose a rainwater purification and reuse bioretention system. The system not only has less operation and low maintenance cost, but also can provide a good environment for plant growth and effectively remove pollutants in rainwater runoff. The difficulty of replenishing water sources in landscape water bodies and the pressure of municipal drainage have good social and environmental benefits.

According to one aspect of the present invention, the present invention proposes a rainwater purification and reuse bioretention system. According to an embodiment of the present invention, the system includes:

A rain garden comprising, from top to bottom, a vegetation layer, a covering layer, a filling layer, a geotextile layer, a supporting layer and a drainage layer, wherein plants are planted in the filling layer and above the covering layer forming the vegetation layer, the filler layer includes natural bag, zeolite, vermiculite and residual sludge from waterworks, the natural bag includes soil, river sand and peat soil, and the covering layer includes wood blocks and bark;

Landscape fountain, the landscape fountain includes a fountain pool, and the fountain pool is provided with a disinfection layer, a water storage layer and a fountain layer in sequence from bottom to top, wherein a sedimentation tank is provided at the bottom of the fountain pool; the disinfection layer is provided with The disinfection layer is connected with the drainage layer, and the fountain pool and the filler layer form a connector structure; the water storage layer is provided with a submersible pump, and the submersible pump connects the water storage layer The water in the fountain is supplied to the fountain water pipe and sprayed out in the fountain layer, and the sprayed water is returned to the water storage layer; the upper part of the fountain layer is provided with a water outlet, and the water outlet is connected with the municipal drainage pipe.

According to the rainwater purification and reuse bioretention system of the above-mentioned embodiment of the present utility model, on the one hand, the inventor found that the excess sludge of the waterworks contains a lot of elements such as iron, aluminum, etc., which has a relatively strong adsorption force for phosphorus, and the tap water The residual sludge from the factory is used in the filling layer of the rain garden, which not only does not affect the growth of plants, but also enables the filling layer to have a good and lasting dephosphorization effect. River sand, peat soil, zeolite, vermiculite and excess sludge from water plants are mixed as a filler layer, which can not only satisfy the growth of plants, but also effectively remove pollutants such as suspended solids, ammonia nitrogen and phosphorus in rainfall runoff. After the rain garden is purified, the removal rate of suspended solids can reach more than 85%, the removal rate of phosphorus can reach more than 93%, the removal rate of ammonia nitrogen can reach 65-85%, and the COD _Cr can be reduced by 65-80%. On the other hand, in the present invention, by using ultraviolet lamps to disinfect the effluent of the rain garden, the effluent can meet the water quality requirements of landscape water, and then using it for landscape fountains can not only improve the benefits of the entire treatment system, but also alleviate our country's The difficulty of replenishing the water source of the urban landscape water body and the pressure of municipal drainage; the water in the water storage layer of the fountain pool is formed into a fountain by the action of the submersible pump for viewing, and then returned to the water storage layer for recycling, which can make the water in the fountain pool in a dynamic state. circulation, ensure the dissolved oxygen content in the water body, and reduce the risk of secondary pollution caused by the deterioration of water quality; in addition, in the present utility model, by forming a communication device structure between the fountain pool and the filler layer, part of the filler layer of the rain garden can also be submerged, An anaerobic zone is formed, which facilitates the growth and reproduction of denitrifying microorganisms and provides more favorable conditions for removing nitrogen from rainfall runoff. To sum up, the system not only has less operation and low maintenance cost, but also can provide a good environment for plant growth and effectively remove pollutants in rainwater runoff. It can also alleviate the difficulty of replenishing water sources for urban landscape water bodies in my country and the pressure of municipal drainage, and has better social and environmental benefits.

In addition, the rainwater purification and reuse bioretention system according to the above-mentioned embodiments of the present utility model may also have the following additional technical features:

Optionally, the particle size of the soil is not greater than 0.5 mm, the particle size of the river sand is 0.06-0.5 mm, and the particle size of the peat soil is not greater than 5 mm. This is not only conducive to the uniform mixing of the components in the packing layer, but also more conducive to the release of nutrients, and makes the natural bag fully contact with the rainwater, which is more conducive to the growth of plants and can achieve a better rainwater purification effect.

Optionally, the particle size of the vermiculite is 0.01-0.06 mm, the particle size of the zeolite is 5-10 mm, and the particle size of the dewatered dry sludge is not greater than 0.5 mm. This can not only make the mixing of the components in the filler layer more uniform, but also facilitate the release of nutrients, and make the vermiculite, zeolite and dewatered dry sludge fully contact with rainwater, which is more conducive to plant growth and energy. To achieve better rainwater purification effect.

Optionally, the thickness of the filler layer is 500-800 mm. This not only provides a more favorable environment for plant growth, but also further improves the purification effect of the rain garden.

Optionally, the thickness of the cover layer is 50-100 mm. Therefore, not only can the covering layer have better water retention and water absorption effects, but also soil erosion of the filling layer can be avoided and a better growth environment for plants can be provided.

Optionally, the thickness of the supporting layer is 200-300 mm. In this way, better supporting and drainage effects can be achieved.

Optionally, the supporting layer is a gravel layer, and the particle size of the gravel is 10-20 mm. This not only achieves a better supporting effect, but also does not affect the drainage effect.

Optionally, the geotextile layer is a non-woven polypropylene filament geotextile layer. In this way, a better water-permeable and sand-impermeable effect can be achieved.

Optionally, the plant is at least one selected from the group consisting of honeysuckle, dwarf crape myrtle, lilac, amorpha, pennisetum, blue fescue, suae, coneflower phlox, and mala.

Optionally, the ultraviolet lamps are arranged side by side along the length direction of the disinfection layer, and the distance between two adjacent ultraviolet lamps is 20-30 cm. In this way, it can be ensured that the water in the disinfection layer can be fully irradiated by the ultraviolet lamp tube, thereby further improving the disinfection effect and avoiding secondary pollution caused by the deterioration of water quality.

Additional aspects and advantages of the invention will be set forth, in part, from the following description, and in part will be apparent from the following description, or learned by practice of the invention.

Description of drawings

The above and/or additional aspects and advantages of the present invention will become apparent and readily understood from the following description of embodiments in conjunction with the accompanying drawings, wherein:

FIG. 1 is a schematic structural diagram of a rainwater purification and reuse bioretention system according to an embodiment of the present invention.

Detailed ways

The following describes in detail the embodiments of the present invention, examples of which are illustrated in the accompanying drawings, wherein the same or similar reference numerals refer to the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary, and are intended to be used to explain the present invention, but should not be construed as a limitation of the present invention.

According to one aspect of the present invention, the present invention proposes a rainwater purification and reuse bioretention system. According to an embodiment of the present invention, as shown in FIG. 1 , the system includes a rain garden 100 and a landscape fountain 200 . The system not only has less operation and low maintenance cost, but also can provide a good environment for plant growth and effectively remove pollutants in rainwater runoff. The difficulty of replenishing water sources in landscape water bodies and the pressure of municipal drainage have good social and environmental benefits.

The rainwater purification and reuse bioretention system of the above-mentioned embodiment of the present invention will be described in detail below with reference to FIG. 1 .

Rain Garden 100

According to the embodiment of the present invention, the rain garden 100 sequentially includes a vegetation layer 110, a covering layer 120, a filler layer 130, a geotextile layer 140, a support layer 150 and a drainage layer 160 from top to bottom, wherein plants are planted in the filler layer A vegetation layer 110 is formed in and over the cover layer 120 in 130, the filler layer 130 includes natural bag, zeolite, vermiculite and residual sludge from waterworks, the natural bag includes soil, river sand and peat soil, and the cover layer 120 includes wood blocks and bark . The inventor found that the excess sludge from the waterworks contains a lot of elements such as iron and aluminum, which has a relatively strong adsorption force for phosphorus. The use of the excess sludge from the waterworks in the packing layer of the rain garden will not only not affect the growth of plants. , the filler layer can also have a good and lasting dephosphorization effect. In this utility model, the rain garden does not need to set up a separate planting soil layer, by mixing soil, river sand, peat soil, zeolite, vermiculite and excess sludge from the water plant As a filler layer, it can not only satisfy the growth of plants, but also effectively remove pollutants such as suspended solids, ammonia nitrogen and phosphorus in rainfall runoff. The removal rate of phosphorus can reach more than 93%, the removal rate of ammonia nitrogen can reach 65-90%, and the COD _Cr can be reduced by 65-85%.

According to a specific embodiment of the present invention, the types of plants in the present invention are not particularly limited, and those skilled in the art can select them according to actual needs. For example, a plant with the function of removing pollutants can be selected from the location of the system, preferably a plant variety that can effectively remove nutrients such as nitrogen and phosphorus, specifically, the plant can be selected from honeysuckle, dwarf crape myrtle, lilac, amorpha, wolfberry At least one of Tailweed, Blue Fescue, Suaeda salsa, Cone phlox and Maliana, this type of plant has at least the following advantages: strong growth ability, can be planted and grown in large quantities; good stress resistance, both resistant to Drought and waterlogging tolerance; proper growth rate and growth cycle; dense and developed plant roots, which can not only increase soil porosity and microbial growth space, but also promote denitrification; coordinate with the ecological environment, with ornamental value and comprehensive utilization value It has good pollution interception and pollution resistance ability, can quickly absorb pollutants in the water body, especially nitrogen, and also has certain pollution resistance. With the continuous entry of rainfall runoff, it has continuous pollution resistance. Preferably, the above-mentioned four kinds of shrubs, honeysuckle, dwarf crape myrtle, lilac, amorpha, and five kinds of herbs, Pennisetum, blue fescue, Suaeda salsa, cone flower phlox, and Malian can be planted in combination.

According to yet another specific embodiment of the present invention, the main function of the covering layer 120 is to retain water, absorb water and protect plants, and it is mainly composed of wood blocks and bark, for example, wood with a mass ratio of 1:(1.0-2.0) The block and bark are evenly mixed and then covered on the filler layer, so that the covering layer can not only have certain water retention, water absorption and permeability, but also avoid soil erosion of the filler layer and provide nutrients for plant growth. Wherein, the thickness of the cover layer 120 can be 50-100mm, such as 50mm, 60mm, 70mm, 80mm, 90mm or 100mm, so that the cover layer can not only have better water retention and water absorption effects, but also avoid the filler layer. Soil erosion and provide a better growing environment for plants. According to a specific example of the utility model, the thickness of the covering layer 120 may be 100mm, and may be composed of wood blocks and bark in a mass ratio of 1:1 or 1:2, thereby further improving the comprehensive effect of the covering layer, and is Plant growth provides a more favorable environment.

According to another specific embodiment of the present utility model, the present utility model does not need to provide a planting soil layer, and plants are planted in the packing layer 130, relying on the packing layer to meet the requirements of plant growth and removal of pollutants in rainfall runoff at the same time, wherein, The removal of nitrogen in rainfall runoff mainly includes biological action, mineralization, precipitation, filtration and the adsorption of fillers, the removal of phosphorus mainly depends on the adsorption of fillers, and the removal of suspended solids mainly depends on filtration and sedimentation. A variety of fillers are mixed evenly and work together to remove pollutants from rainfall runoff. Specifically, soil, river sand and peat soil can be mixed and formulated into a natural bag to meet the growth of plants, and then zeolite and vermiculite with ammonia nitrogen removal effect and phosphorus removal effect are further added on the basis of natural bag. The residual sludge in the water works, so that the filler layer has a better pollutant removal effect.

According to another specific embodiment of the present invention, the mass ratio of soil, river sand and peat soil in the natural bag may be (40-50):(30-40):(10-20), for example, it may be 46:36 : 18. The inventor found that adding an appropriate amount of river sand to the filler layer can help improve the permeability of the filler, but if the amount of river sand is too much, it is not conducive to the growth of plants; and the main component of peat soil is pure Natural organic matter, rich in nitrogen, phosphorus, potassium, calcium, manganese and other elements, is a sterile, non-toxic, non-polluting, non-polluting, non-residue green substance that can improve soil, restore and improve The ability of soil to hold water, aeration and fertilizer, and increase the nutrient content of the soil, adding an appropriate amount of peat soil to the filler layer can not only provide nutrients for plant growth, but also ensure that even if the content of nutrients in the soil is low, plant growth can be satisfied , can also improve the ability to remove pollutants; in the utility model, by controlling the soil, river sand and peat soil to be the above-mentioned mass ratio, not only the soil can be improved, a better soil environment can be provided for plant growth, but also the filler layer can be improved. Decontamination and penetration of water. Further, the soil selected in the present utility model can be the planting soil where the system is located. For example, planting soil with a lower nutrient content can be selected, and the soil can be sieved to remove particles with larger particle sizes, so that the soil particle size can be reduced. Not more than 0.5mm, in addition, the particle size of the river sand used in the present utility model can be 0.06-0.5mm, and the particle size of the peat soil can be no larger than 5mm, thereby ensuring that the soil, river sand and peat soil can be The fillers are mixed evenly.

According to another specific embodiment of the present invention, the mass ratio of natural bag, zeolite, vermiculite and dewatered dry sludge may be (50-70): (5-20): (5-20): (10-30) , The inventor found that the excess sludge from the water plant contains more elements such as iron and aluminum, which has a relatively strong adsorption force for phosphorus. Using the excess sludge from the water plant in the filler layer of the rain garden can make the filler layer have Good and long-lasting dephosphorization effect; and, as a natural non-toxic mineral, vermiculite has good cation exchange and adsorption, which can not only improve soil structure, water storage and moisture retention, but also improve soil air permeability and adsorption. It is water-bearing and can also remove ammonia nitrogen, phosphate, rare earth ions and organic pollutants in water; zeolite has the effect of water and fertilizer retention, and its surface is positively charged, rough and porous, and has a strong ability to adsorb ammonia nitrogen. Exchange, the removal rate of ammonia nitrogen can reach more than 95%. In the utility model, the filler layer is formed by mixing natural bag, zeolite, vermiculite and the excess sludge of the water plant and controlling the above ratio, which can not only provide sufficient nutrients and a good growth environment for plant growth, but also achieve better It ensures that the removal rate of suspended solids is not less than 85%, the removal rate of phosphorus is not less than 93%, the removal rate of ammonia nitrogen is not less than 68%, and the COD _Cr can be reduced by 65% after the rainwater runoff is purified by the rain garden. %above.

According to another specific embodiment of the present utility model, the residual sludge of the waterworks used in the present utility model is dewatered dry sludge, which can be ground into powder with a particle size of not more than 0.5 mm, and the particle size of the vermiculite can be controlled. It is 0.01-0.06mm, and the particle size of zeolite is 5-10mm, which not only ensures a more uniform mixing of natural bag, zeolite, vermiculite and excess sludge from the water plant, but also is more conducive to the release of nutrients, and makes the filler layer more uniform. The components in the water are in full contact with the rainwater, which is more conducive to the growth of plants and can achieve a better rainwater purification effect. In addition, the thickness of the filler layer 130 may be 500-800mm, for example, may be 500mm, 550mm, 600mm, 650mm, 700mm, 750mm or 800mm, etc., thereby not only providing a more favorable environment for plant growth, but also further ensuring the filler layer Physical, chemical and biological effects on pollutants, including mineralization, precipitation, filtration and adsorption, etc., so as to achieve a better rainwater purification effect.

According to another specific embodiment of the present invention, the organic matter content in the filler layer may be 3-5 wt%, the clay content is preferably not more than 5 wt%, the nitrogen content is preferably not more than 1000 mg/Kg, and the phosphorus content is preferably not more than 80 mg/Kg. It has been found that the water passing rate of the packing layer is generally required to reach 25-50 mm/h. If the clay content in the packing layer is too large, when the rainwater seeps in, the water passing rate of the packing layer will be significantly reduced, and the permeability of the packing layer will be poor. It affects the purification efficiency of the rain garden; and when the nitrogen content or phosphorus content in the filler layer is too high, a part of nitrogen and phosphorus elements will be released in the filler layer, which will affect the removal effect of the filler layer on nitrogen and phosphorus in the water body. In the utility model, by controlling the organic matter, clay, nitrogen and phosphorus in the filler layer to be the above-mentioned contents, not only sufficient nutrients can be provided for plant growth, but also the filler layer can be ensured to have suitable water permeation, and better removal of nitrogen and phosphorus can be achieved. Effect. According to another specific embodiment of the present invention, the geotextile layer 140 mainly plays the role of isolating the filler layer 130 and the support layer 150, so as to avoid the leakage of the filler to the support layer. Non-woven high tenacity polypropylene filament is used as a geotextile layer, which can achieve better water permeability and sand impermeability.

According to another specific embodiment of the present invention, the supporting layer 150 mainly plays the functions of supporting and draining, which can not only prevent the loss of other fillers but also play the role of rapid drainage. The supporting layer can be a gravel layer, the particle size of the gravel can be 10-20 mm, and the thickness of the supporting layer can be 200-300 mm, which can not only achieve a better supporting effect, but also affect the drainage effect. In addition, in the rain garden, a water outlet pipe may be provided at the bottom of the drainage layer 160, thereby preventing the water from the rain garden from directly entering the groundwater.

Landscape Fountain 200

According to the embodiment of the present invention, the landscape fountain 200 includes a fountain pool 210, and the fountain pool 210 is provided with a disinfection layer 211, a water storage layer 212 and a fountain layer 213 in sequence from bottom to top, wherein the bottom of the fountain pool is provided with a sedimentation tank 220; The disinfection layer 211 is provided with an ultraviolet lamp 230, and the disinfection layer 211 is connected with the drainage layer 160, and the fountain pool 210 and the filler layer 130 form a connector structure; The water in the water is supplied to the fountain water pipe 250 and sprayed at the fountain layer 213, and the sprayed water is returned to the water storage layer 212; the upper part of the fountain layer 213 is provided with a water outlet 260, and the water outlet 260 is connected with the municipal drainage pipe. In the utility model, the effluent of the rain garden can meet the water quality requirements of landscape water by using ultraviolet lamps to disinfect the effluent of the rain garden, and the combined use of the landscape fountain and the rain garden can not only improve the benefit of the whole treatment system, but also alleviate the problems of urban water in our country. The difficulty of replenishing the water source of the landscape water body and the pressure of municipal drainage; and, the water in the water storage layer of the fountain pool is formed into a fountain by the action of the submersible pump for viewing, and then returned to the water storage layer for recycling, which can make the water in the fountain pool in a dynamic state. circulation to ensure the dissolved oxygen content in the water body and reduce the risk of secondary pollution caused by the deterioration of water quality; in addition, by forming a connector structure between the fountain pool and the filler layer, part of the filler layer of the rain garden can be submerged, forming an anaerobic zone , so as to help the growth and reproduction of denitrifying microorganisms and provide more favorable conditions for removing nitrogen from rainfall runoff; and setting the water outlet on the upper part of the fountain layer to connect with the municipal drainage pipe can not only make the rain garden water as much as possible. For landscape fountains, it can also avoid the phenomenon of water overflow in the fountain pool due to excessive rainfall.

According to a specific embodiment of the present invention, the ultraviolet lamps 230 can be arranged side by side along the length direction of the disinfection layer 211, for example, they can be arranged horizontally or vertically, and the distance between two adjacent ultraviolet lamps can be 20-30 cm . By adopting the above arrangement in the present invention, it can be ensured that the water in the disinfection layer can be fully irradiated by the ultraviolet lamp tube, thereby further improving the disinfection effect and avoiding secondary pollution caused by the deterioration of water quality. It should be noted that the longitudinal direction of the disinfection layer described in the present invention is based on the longitudinal direction shown in FIG. 1 .

According to another specific embodiment of the present invention, the sedimentation tank 220 can further settle the sand that may exist in the effluent of the rain garden, and keep the water in the landscape fountain clear; out), so that the sediment in the settling tank can be periodically removed through the sand outlet.

According to another specific embodiment of the present invention, the general principles for setting the volume of the fountain pool 210 include: 1. Collect as much water as possible from the rainwater garden, and try to avoid the treated rainwater being discharged into the municipal drainage pipe network; 2. Possibly simplify the design of fountain pools and reduce maintenance and operating costs. Among them, the volume of the fountain pool can be:

V=Ψh _m aK,

Among them, where V—is the volume of the fountain pool, m ³ ; Ψ—is the rainfall runoff coefficient; h _m —is the designed rainfall intensity corresponding to the total annual runoff control rate of 80% to 85%, mm; a—is the rain garden Covering area, hm ² ; K—the ratio of the rain garden service area to its area, and the value of K ranges from 10 to 20. As a result, not only can the water from the rain garden be fully used for landscape fountains as much as possible to reduce the pressure of municipal drainage, but also the maintenance and operation costs of the fountain pool can be further reduced. It should be noted that, in this utility model, the service area of the rain garden includes the area of the catchment area of the rain garden and the area of the rain garden, and the area of the rain garden is 5-10% of the catchment area; in addition, h _m can be the design rainfall intensity corresponding to the total annual runoff control rate of 80%, 81%, 82%, 83%, 84% or 85%.

According to the embodiment of the present invention, when it rains, the rainfall runoff in the catchment area around the rain garden enters the rain garden part through side ditch or other facilities, and the pollutants (suspended solids, COD _Cr , ammonia nitrogen and total phosphorus) carried in the rainfall runoff ) It is purified by the covering layer, vegetation layer, packing layer, geotextile layer, supporting layer and water outlet layer in the rain garden, and then enters the disinfection layer of the fountain pool, and is disinfected under the action of ultraviolet lamps, so that the water can reach the landscape. According to the water quality requirements, it gradually enters the water storage layer of the fountain pool, and the water in the water storage layer forms a fountain through the action of the submersible pump for viewing, and finally returns to the water storage layer for recycling.

To sum up, the rainwater purification and reuse bioretention system of the above-mentioned embodiments of the present utility model has at least the following advantages: 1. The residual sludge from the waterworks is used in the filling layer of the rain garden, which not only does not affect the growth of plants, but also can The filler layer has a good and long-lasting dephosphorization effect; 2. There is no need to set up a separate planting soil layer. By mixing soil, river sand, peat soil, zeolite, vermiculite and excess sludge from water plants as the filler layer, it can not only meet the needs of plants It can also effectively remove pollutants such as suspended solids, ammonia nitrogen and phosphorus in rainfall runoff. After the rainwater runoff is purified by the rain garden, the removal rate of suspended solids can reach more than 85%, and the removal rate of phosphorus can reach 93%. Above, the removal rate of ammonia nitrogen can reach 65-90%, and COD _Cr can be reduced by 65-85%; 3. By using ultraviolet lamps to disinfect the effluent of the rain garden, the effluent can meet the water quality requirements of landscape water, and then use it with The landscape fountain can not only improve the comprehensive benefits of the entire treatment system, but also alleviate the difficulty of supplementing the water source of urban landscape water bodies in China and the pressure of municipal drainage; 4. The water in the water storage layer of the fountain pool forms a fountain through the action of the submersible pump for viewing, Then return to the water storage layer for recycling, which can make the water in the fountain pool in dynamic circulation, ensure the dissolved oxygen content in the water body, and reduce the risk of secondary pollution caused by the deterioration of water quality; 5. By forming a connector between the fountain pool and the packing layer The structure can also make part of the filling layer of the rain garden in a submerged state, forming an anaerobic zone, which helps the growth and reproduction of denitrifying microorganisms and provides more favorable conditions for removing nitrogen from rainfall runoff; 6. As much as possible The water from the rain garden is fully used for landscape fountains to reduce the pressure of municipal drainage.

The present invention will be described below with reference to specific embodiments. It should be noted that these embodiments are only illustrative and do not limit the present invention in any way.

Example 1

Three packing layers with different compositions were designed to simulate artificial rainfall to evaluate the purification effect of the packing layers. Among them, the thickness of the filler layer is 600mm, and the filler layer is composed of natural bag, zeolite, vermiculite and residual sludge from the water plant, wherein the natural bag is soil, river sand and peat soil with a mass ratio of 46:36:18. Among them, the mass ratio of natural bag, zeolite, vermiculite and dry sludge of waterworks in the packing layer, the concentration of suspended solids, COD _Cr , ammonia nitrogen and total phosphorus in rainfall, and the removal rate of each pollutant are shown in Table 1.

Table 1 Removal effects of different compositions of filler layers on pollutants in rainfall

It can be seen from Table 1 that the removal rate of phosphorus from rainfall is higher when the excess sludge from the water works in the filler layer is more.

In the description of this specification, description with reference to the terms "one embodiment," "some embodiments," "example," "specific example," or "some examples", etc., mean specific features described in connection with the embodiment or example , structure, material or feature is included in at least one embodiment or example of the present invention. In this specification, schematic representations of the above terms are not necessarily directed to the same embodiment or example. Furthermore, the particular features, structures, materials or characteristics described may be combined in any suitable manner in any one or more embodiments or examples. Furthermore, those skilled in the art may combine and combine the different embodiments or examples described in this specification, as well as the features of the different embodiments or examples, without conflicting each other.

Although the embodiments of the present invention have been shown and described above, it should be understood that the above embodiments are exemplary and should not be construed as limitations of the present invention, and those of ordinary skill in the art are within the scope of the present invention Variations, modifications, substitutions and variations can be made to the above-described embodiments.

Claims (10)

1. The utility model provides a rainwater purifies retrieval and utilization bioretention system which characterized in that includes:

the rainwater garden sequentially comprises a vegetation layer, a covering layer, a packing layer, a geotextile layer, a bearing layer and a drainage layer from top to bottom, wherein plants are planted in the packing layer, the vegetation layer is formed above the covering layer, the packing layer comprises natural bags, zeolite, vermiculite and surplus sludge of a waterworks, the natural bags comprise soil, river sand and turfy soil, and the covering layer comprises wood blocks and barks;

the landscape fountain comprises a fountain pool, wherein the fountain pool is sequentially provided with a disinfection layer, a water storage layer and a fountain layer from bottom to top, and the bottom of the fountain pool is provided with a settling tank; the disinfection layer is provided with an ultraviolet lamp tube and is connected with the drainage layer, and the fountain pool and the filler layer form a communicating vessel structure; the water storage layer is provided with a submersible pump, the submersible pump supplies water in the water storage layer to a fountain water pipe and sprays out of the fountain layer, and the sprayed water returns to the water storage layer; and a water outlet is formed in the upper part of the fountain layer and is connected with a municipal drainage pipe.

2. The system as claimed in claim 1, wherein the soil has a particle size of not more than 0.5mm, the river sand has a particle size of 0.06-0.5 mm, and the peatmoss has a particle size of not more than 5 mm.

3. The system according to claim 1 or 2, wherein the particle size of the vermiculite is 0.01-0.06 mm, the particle size of the zeolite is 5-10 mm, and the particle size of the waterworks residual sludge is not more than 0.5 mm.

4. The system of claim 3, wherein the filler layer has a thickness of 500 to 800 mm.

5. The system of claim 1 or 4, wherein the thickness of the cover layer is 50-100 mm.

6. The system of claim 5, wherein the support layer has a thickness of 200-300 mm.

7. The system of claim 1 or 6, wherein the support layer is a gravel layer, and the gravel has a particle size of 10-20 mm.

8. The system of claim 7, wherein the geotextile layer is a nonwoven polypropylene filament geotextile layer.

9. The system according to claim 1 or 8, wherein the plant is at least one selected from the group consisting of honeysuckle, dwarf lagerstroemia indica, sidacea, amorpha fruticosa, pennisetum alopecuroides, festuca arundinacea, suaeda glauca, congola fulu and martian.

10. The system of claim 9, wherein the ultraviolet lamp tubes are arranged side by side along the length direction of the disinfection layer, and the distance between two adjacent ultraviolet lamp tubes is 20-30 cm.

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