CN107288198B - A rain garden system that protects the bottom denitrification anaerobic zone - Google Patents

Abstract

The invention discloses a rain garden system capable of protecting the bottom denitrification anaerobic area, comprising a pre-pond, the pre-pond includes a settlement area and a transition area, and a sludge pump is arranged at the bottom of the settlement area, and the sludge pump is connected with pressure sludge discharge The settlement area is connected with the transition area through the filter material area, and the transition area is connected with the rainwater retention area through the discharge pipe of the pre-tank. In the rainwater retention area, the first water storage area, the soil layer, the gravel layer and the composite reflection area are arranged in sequence. The seepage layer, the gravel layer is provided with a water collection pipe, the rainwater retention area is provided with an external pool body, the external pool body is provided with a second water storage area, the first water storage area is provided with a fourth overflow pipe, and the rainwater passes through the fourth overflow pipe. The flow pipe overflows into the external pool body, and a second overflow pipe is arranged on the external pool body to discharge the overflowed rainwater into the municipal sewage pipe network. The invention has a reasonable structure, can collect the surface runoff rainwater in the residential area and perform advanced treatment on it, can not only improve the flood detention effect but also realize the strengthening of runoff rainwater pollution control.

Description

A rain garden system that protects the bottom denitrification anaerobic zone

technical field

The invention relates to a rain garden system capable of protecting a bottom denitrification anaerobic zone, belonging to the field of urban ecology.

Background technique

In recent years, my country's environmental problems have received more and more attention. The construction of ecological civilization has also become an important program for the construction of new urban areas and residential areas in my country. The urban waterlogging problem has seriously affected the normal life and travel of our residents, and has laid a serious hidden danger for the lives and property safety of the people. In order to solve this problem, my country has issued a number of relevant policies and regulations in recent years to vigorously develop the construction of sponge cities.

In the construction of new urban areas, the collection and advanced treatment of runoff rainwater is particularly important, and in the rain garden system, the key facility for rainwater collection and treatment is the bioretention facility. For traditional bioretention tanks, due to the large amount of pore water evaporation at the bottom of the traditional retention tank under long-term drought, the anaerobic environment at the bottom has been destroyed, and denitrification has been inhibited. After that, an improved process has been developed—— —The submerged area is set in the bottom water collection pipe, so that the problem has been solved in stages, but the submerged area can only exist during the rainwater infiltration process of a single rainfall. In the static state, a large amount of water will also evaporate under long-term drought, and the anaerobic environment at the bottom cannot be maintained for a long time, which will reduce the decontamination effect of the detention pond.

For example, the patent (application number: 201420025661.5): a bioretention pond that enhances the nitrogen removal effect in storm runoff. Ensure the continuous water outlet of the water collection pipe, so that dead water area will be formed at the bottom, which will affect the water quality of the next rainfall. This device can solve this problem very well. The rainwater in the second water storage area can protect the anaerobic environment at the bottom of the retention area through reverse osmosis during the drought period, and at the same time ensure the continuous water outlet of the water collection pipe. The entire reverse osmosis process Relying on the height difference of the natural water level, it can be carried out automatically without manual intervention or external additional power facilities. It is energy-saving and environmentally friendly. It not only enhances the decontamination effect but also increases the flood detention capacity, which has positive guiding significance for the construction of new communities.

Contents of the invention

Purpose of the invention: In order to overcome the deficiencies in the prior art, the present invention provides a rain garden system that can protect the bottom denitrification anaerobic zone, has a reasonable structure, and can collect surface runoff rainwater in the community and perform advanced treatment on it, both It can improve its flood detention effect and strengthen the control of runoff and rainwater pollution.

Technical solution: In order to solve the above technical problems, a rain garden system that can protect the bottom denitrification anaerobic area of the present invention includes a pre-pond, the pre-pond includes a settlement area and a transition area, and the settlement area is connected with the municipal rainwater pipe The inlet pipe connected to the network is connected, and a sludge pump is installed at the bottom of the settlement area, and the sludge pump is connected to the pressure sludge discharge pipe. The settlement area is connected to the transition area through the filter material area, and the transition area is connected to the rainwater retention area through the discharge pipe of the front tank connection, the first water storage area, soil layer, gravel layer, gravel layer and composite reverse osmosis layer are arranged in sequence in the rainwater retention area, and the collection pipe is arranged in the gravel layer; The body is provided with a second water storage area, the first water storage area is provided with a fourth overflow pipe, rainwater overflows through the fourth overflow pipe and enters the second water storage area in the outer pool body, and the outer pool body is provided with a fourth overflow pipe. The second overflow pipe discharges the overflowing rainwater into the municipal sewage pipe network.

Preferably, the outer pool body is circular, and the rainwater retention area includes four retention units, which are two front retention units and two rear retention units, each retention unit is fan-shaped, and each retention unit is from top to bottom The first water storage area, the soil layer, the sand and gravel layer, the gravel layer and the composite reverse osmosis layer in sequence, each gravel layer is equipped with a water collection pipe, the discharge pipe of the pre-tank and the first water storage area of the two former retention units The two rear retention units communicate with the front retention unit through the third overflow pipe, and the fourth overflow pipe is located on the rear retention unit.

As a preference, the elevation of the top of the discharge pipe of the pre-tank shall not be higher than the elevation of the bottom of the inlet pipe of the pre-tank, and the first overflow pipe is provided in the settling area, and the elevation of the bottom of the first overflow pipe shall be higher than that of the bottom of the pre-tank. The elevation of the top of the pool discharge pipe should be at least 100mm; the bottom of the pre-tank is set on a slope, and the bottom elevation of the sludge pump is the lowest elevation inside the pre-tank to ensure the smooth collection of particles and silt in the influent ; The filter material area is a detachable filter material, the outside is an integral frame, and the filter material installed inside is composed of three layers of filter materials, from left to right are gravel layer, sand filter layer and gravel layer.

Preferably, the composite reverse osmosis layer is made of a composite inorganic degradable material with a permeation rate of 0.071-0.075m/d, and the permeation rate of the soil layer is 0.500-0.55m/d, which is about 7% of the reverse osmosis layer. times, to ensure that the seepage process of the water in the first water storage area through the soil layer lasts for only 1 day, while the water in the second water storage area can last for about 7 days through the reverse osmosis process of the composite reverse osmosis layer, thus ensuring the normal operation of the system.

As preferably, the plants planted in the soil layer of the front retention unit are emergent plants with good flood tolerance (such as: cattail narrow leaves, etc.), and the plants planted in the soil layer of the rear retention unit are herbs with good drought tolerance Plants (such as: snapdragon, etc.), make the system have good adaptability to rainfall of different intensities, and ensure that the system can operate normally under different rainfall conditions.

As preferably, the highest water depth of the water storage area of the front retention unit is at least 100 mm higher than the highest water depth of the first water storage area of the rear retention unit, and the settings of the remaining physical heights of the four areas are all the same; The water level is about 150mm lower than the highest water level in the third and fourth areas; meanwhile, the overflow height of the second water storage area is more than 500mm higher than the submerged height of the water collection pipe to ensure the normal operation of the system.

Preferably, an annular air pipeline is provided in the second water storage area, and the annular air pipeline is connected to an air pressurizing device, and a clear water pipeline is provided on the second water storage area.

As a preference, the annular air pipeline includes an outer ring pipeline and an inner ring pipeline, the inner ring pipeline and the outer ring pipeline are connected through the inner and outer ring connecting pipes, and several The opening directions of the exhaust holes set on the inner and outer circles are vertically downward and evenly arranged on the inner and outer circles to ensure the uniformity of the system air distribution.

In the present invention, when it rains, the rainwater is preliminarily filtered through the filter material area of the front pool, and then enters the retention area of the main body of the rain garden through the discharge pipe of the front pool, wherein the discharge pipe is horizontally divided into two branch pipes after entering the rain garden. Connected to the first retention area and the second retention area, the rainwater enters the front retention unit through the discharge pipe at the same time. After the front retention unit is full of water, it enters the rear retention unit through two sets of third overflow pipes at the same time. When the rear retention unit is full of water , the rainwater will enter the second water storage area of the rain garden through two sets of fourth overflow pipes. After the second water storage area is full, the excess rainwater will be discharged from the rain garden system through the second overflow pipe and discharged into the municipal sewage pipe network.

In the present invention, the water exchange and desilting equipment is manually opened or closed. Before opening, it needs to be estimated in conjunction with the local weather forecast. For excessive deposition, the water change and desilting equipment should be fully opened at least once a month during the dry period (that is, the clean water pipeline and air pressurization equipment are opened at the same time); if the rainfall interval exceeds 14 days, the equipment should be fully opened once every seven days or so , carry out water exchange and dredging in the second water storage area to ensure that the water in this part will not stay for too long and become stagnant water after the reverse osmosis is completed, and at the same time protect the anaerobic environment at the bottom of the rainwater retention area from being damaged. Maintain the stability of the detention area for handling stormwater.

In the present invention, the top of the rain garden is an ornamental area, including sidewalks for tourists and safety guardrails, wherein the sidewalks are set according to the shape of the main body of the rain garden, and the sidewalks are designed as two-way streets with a width of more than 2m, which can be specifically considered according to the geographical conditions of the residential area; The height of the safety fence is about 1.2m to ensure the personal safety of tourists.

Beneficial effects: the rain garden system of the present invention can protect the bottom denitrification anaerobic area, the gradient water intake mode of the four stagnation areas enables the rain garden to adapt to rainfall of different intensities, and the added second water storage area can increase the overall rain garden At the same time, due to the large difference in porosity between the soil layer and the composite reverse osmosis layer, the water in the second water storage area can still continue to reverse upward during the drought period and maintain Reverse osmosis process of about 7 days; some dry time exceeds 14 days, in order to avoid the remaining rainwater at the bottom of the second water storage area from becoming stagnant water due to long-term retention, the present invention is provided with water exchange and desilting equipment and regularly operated manually, In order to ensure the regular renewal of the water in the second water storage area, it can also prevent the sediment from accumulating and affecting the stability of the system operation; from the perspective of eco-environmental friendliness, it can be applied to the construction of ecological residential areas on a large scale Among them, it has the characteristics of good compatibility.

Description of drawings

Fig. 1 is the front view of the facade structure of the preponder of the present invention.

Fig. 2 is a schematic diagram of the layout of the front pool of the present invention.

Fig. 3 is a left view of the facade structure of the preponder of the present invention.

Fig. 4 is a schematic diagram of the facade structure of the main body of the rain garden of the present invention.

Fig. 5 is a top plan view of the main body of the rain garden of the present invention.

Fig. 6 is an A-A sectional view of the main body of the rain garden of the present invention.

Fig. 7 is a B-B sectional view of the main body of the rain garden of the present invention.

Fig. 8 is a facade elevation layout diagram of the present invention.

Fig. 9 is a schematic plan view of the present invention.

Reference signs: 1-water inlet pipe, 2-the first overflow pipe, 3-pre-tank settlement area, 4-sludge pump, 5-pre-tank filter area (5.1-gravel layer, 5.2-sand filter layer ), 6- transition area of pre-tank, 7- pressure mud discharge pipe, 8- discharge pipe of pre-tank, 9- second overflow pipe, 10- second water storage area, 11- safety fence, 12- soil layer , 13-composite reverse osmosis layer, 14-third overflow pipe, 15-fourth overflow pipe, 16-annular air pipeline (16.1-outer ring pipeline, 16.2-inner ring pipeline, 16.3-inner and outer ring Connecting pipe, 16.4-exhaust hole), 17-air pressurization equipment, 18-clean water pipeline, 19-water collection pipe (19.1-water collection pipe water collection hole), 20-sidewalk, 21-first water storage area, 22-Gravel layer in the retention area, 23-Gravel layer in the retention area, 24-Rainwater retention area.

Detailed ways

As shown in Figures 1 to 9, a rain garden system that can protect the bottom denitrification anaerobic zone of the present invention includes a front pond, and the front pond includes a settlement zone 3 and a transition zone 6, and the settlement zone 3 and It is connected to the water inlet pipe 1 connected to the municipal rainwater pipe network. A sludge pump 4 is provided at the bottom of the settlement area 3. The sludge pump 4 is connected to the pressure sludge discharge pipeline 7. The settlement area 3 is connected to the transition area 6 through the filter material area 5, and the transition area Area 6 is connected to the rainwater retention area through the pre-tank discharge pipe 8. In the rainwater retention area, the first water storage area 21, soil layer 12, sand and gravel layer 22, gravel layer 23 and composite reverse osmosis layer 13, gravel layer 23 is provided with a water collection pipe 19, and an external pool body is provided outside the rainwater retention area. The external pool body is provided with a second water storage area 10, and the first water storage area 21 is provided with a fourth overflow pipe 15, and the rainwater passes through the fourth overflow pipe. The flow pipe 15 overflows into the second water storage area 10 in the outer pool body, and the second overflow pipe 9 is arranged in the outer pool body to discharge the overflowed rainwater into the municipal sewage pipe network.

In the present invention, the outer pool body is circular, and the rainwater retention area 24 includes four retention units 24.1, 24.2, 24.3, 24.4, which are respectively two front retention units 24.1, 24.2 and two rear retention units 24.3, 24.4 , each retention unit is fan-shaped, each retention unit is the first water storage area 21.1 or 21.2 or 21.3 or 21.4, soil layer 12, gravel layer 22, gravel layer 23 and composite reverse osmosis layer 13 from top to bottom, each Each gravel layer 23 is provided with a water collection pipe 19, the pre-tank discharge pipe 8 is connected with the first water storage area of the two front retention units 24.1, 24.2, and the two rear retention units 24.3, 24.4 pass through the third overflow pipe 14 In communication with the front retention units 24.1, 24.2, a fourth overflow pipe 15 is located on the rear retention units 24.3, 24.4.

In the present invention, the pipe top elevation of the pre-tank discharge pipe 8 must not be higher than the pipe bottom elevation of the pre-tank inlet pipe 1, and the settling area 3 is provided with the first overflow pipe 2, and the first overflow pipe 2 The elevation of the bottom of the pipe should be at least 100mm higher than the elevation of the top of the discharge pipe 8 of the pre-stage pool; the bottom of the pre-stage pool is set on a slope, and the bottom elevation of the place where the sludge pump is installed is the lowest elevation inside the pre-stage pool to ensure water inflow The smooth collection of medium particles, silt, etc.; the filter material area 5 is a detachable filter material, the outside is an integral frame, and the filter material installed inside is composed of three layers of filter materials, from left to right are gravel layer 5.1, sand filter Layer 5.2 and gravel layer 5.1.

In the present invention, the composite reverse osmosis layer 13 is made of a composite inorganic degradable material with very little porosity (permeation rate is 0.071-0.075m/d), and the porosity of the soil layer 12 (permeation rate is 0.500-0.500- 0.55m/d) is obviously greater than the porosity of the composite reverse osmosis layer 13. The plants planted in the soil layer 12 of the front retention unit are emergent plants with good flood tolerance (such as: cattail narrow leaves, etc.), and the plants planted in the soil layer 12 of the rear retention unit are herbaceous plants with good drought tolerance (such as: snapdragon, etc.), to ensure that the system can operate normally under different rainfall conditions.

In the present invention, the maximum water depth of the first water storage area of the front retention unit 24.1, 24.2 is at least 100mm higher than the maximum water depth of the first water storage area of the rear retention unit 24.3, 24.4, and the settings of the physical heights of the remaining four areas are equal. The same as each other; the highest water level of the second water storage area 10 is about 150mm lower than the highest water level of the rear retention units 24.3 and 24.4; meanwhile, the overflow height of the second water storage area 10 is higher than the submerged height of the water collection pipe 19 by more than 500mm, to ensure normal functioning of the system.

In the present invention, an annular air pipeline 16 is provided in the second water storage area 10, and the annular air pipeline 16 is connected to an air pressurizing device 17, and a clear water pipeline 18 is provided on the second water storage area 10 . The annular air pipeline 16 includes an outer ring pipeline 16.1 and an inner ring pipeline 16.2, the inner ring pipeline 16.2 communicates with the outer ring pipeline 16.1 through an inner and outer ring connecting pipe 16.3, and the outer ring pipeline 16.1 and the inner ring pipeline Several exhaust holes 16.4 are evenly arranged on 16.2, and the opening directions of the exhaust holes 16.4 set on the inner and outer circles are both vertically downward and evenly arranged on the inner and outer circles, so as to ensure the uniform air distribution of the system sex.

The system includes two different working conditions, which are operating conditions and maintenance conditions.

Under operating conditions, the surface runoff rainwater collected by the municipal rainwater pipe network enters the settlement area 3 of the pre-stage pond through the water inlet pipe 1, enters the pre-stage pond transition area 6 after being initially filtered by the pre-stage pond filter area 5, and then passes through the discharge pipe 8 The stormwater retention zone 1 and the stormwater retention zone 2 entering the rain garden at the same time. When the rainfall is small, the rainwater will only be stored in the first zone and the second zone; when the rainfall is heavy, the rainwater will first fill the first zone and the second zone, and then overflow into the third zone through two sets of third overflow pipes 14. district and four districts of retention, after the four rainwater retention districts are all full of water, excess rainwater will enter the second water storage district 10 through two groups of fourth overflow pipes 15, if the second water storage district 10 is full of water , and the rainwater is directly discharged into the municipal sewage pipe network through the second overflow pipe 9.

Under the action of gravity, the rainwater in the first water storage area 21 slowly infiltrates through the soil layer 12 and is discharged from the rain garden system through the water collection pipe 19. The duration of this process is about 1 day; the rainwater in the second water storage area 10 Under the action of the water level difference, the composite reverse osmosis layer 13 reverses to the stagnation area and is discharged from the system through the water collection pipe 19. The duration of this process is about 7 days.

Under maintenance conditions, the water exchange and desilting equipment is manually turned on, and when the water level in the second water storage area 10 returns to the height of the submerged area of the water collection pipe 19, the air pressurization device 17 is turned on to expose the remaining water in the second water storage area 10. At the same time, the sediment at the bottom is resuspended under the scouring of high-pressure gas and highly mixed with the remaining water. The aeration time is about 10 minutes. After that, clean water at normal pressure is injected into the second water storage area 10 through the clean water pipeline 18, and the water injection Keep the air pressurization device 17 open during the process so that the water in the second water storage area 10 keeps a highly turbulent state at any time. When the water level rises to the overflow height of the fourth overflow pipe 9, continue to pour water for about 20 minutes, so that All sediments in the second water storage area 10 are quickly discharged from the system through the fourth overflow pipe 9, and then the water exchange and desilting equipment is closed. So far, the water in the second water storage area 10 has been replaced with clean water without pollution. Under the height difference between the inner and outer water levels, another reverse osmosis process is started to keep the anaerobic area at the bottom of the stagnation area in a submerged and flowing state at any time. . In addition, the detachable filter material area 5 in the pre-tank should be taken out as a whole under maintenance conditions, and the filter material should be washed or replaced; at the same time, the sludge pump 4 is manually opened to discharge the deposited sediment from the system to ensure The normal operation of the front pool.

The above is only a preferred embodiment of the present invention, it should be pointed out that for those of ordinary skill in the art, without departing from the principle of the present invention, some improvements and modifications can also be made. It should be regarded as the protection scope of the present invention.

Claims (5)

1. the Rain Garden system that one kind can protect bottom denitrification anaerobic area, it is characterised in that: including preposition pond, preposition Chi Bao Containing decanting zone, transition region, the decanting zone with and the water inlet pipe that is connected of municipal Storm Sewer Network connect, decanting zone bottom is equipped with dirty Dredge pump, sludge pump are connect with pressure spoil disposal pipeline, and decanting zone is connect by filtrate area with transition region, and transition region is arranged by preposition pond Outlet pipe is connect with rainwater stagnant area, be successively arranged in rainwater stagnant area the first water reserve, soil horizon, grit layer, gravel layer and Compound reverse osmosis layer is equipped with collector pipe in gravel layer, and rainwater stagnant area is externally provided with external pond body, and external pond body is equipped with the second water storage Area, the first water reserve are equipped with the 4th overflow pipe, and rainwater is entered in external pond body by the 4th overflow pipe overflow, in external pond body Equipped with the second overflow pipe, the rainwater of overflow is drained into municipal sewage pipe network, wherein the external pond body is circle, rainwater Stagnant area includes four delay units, is detained unit after unit and two are detained before respectively two, each delay unit is fan Shape, each delay unit are followed successively by the first water reserve, soil horizon, grit layer, gravel layer and compound reverse osmosis layer from top to bottom, each Collector pipe is equipped in gravel layer, preposition pond discharge pipe connect with the first water reserve for being detained unit before two, is detained after two Unit is connected to by third overflow pipe with preceding delay unit, and the 4th overflow pipe is detained on unit after being located at.

2. the Rain Garden system according to claim 1 for protecting bottom denitrification anaerobic area, it is characterised in that: described The plant planted in the preceding soil horizon for being detained unit is the good emergent aquactic plant of ability of inundation, plantation in the rear soil horizon for being detained unit Plant be the good herbaceous plant of drought tolerance.

3. the Rain Garden system according to claim 1 for protecting bottom denitrification anaerobic area, it is characterised in that: described First water reserve highest depth of water 100mm of delay unit after the preceding first water reserve highest depth of water for being detained unit is at least above, four The setting of a remaining physical height of area is mutually identical.

4. the Rain Garden system according to claim 1 for protecting bottom denitrification anaerobic area, it is characterised in that: described Annular air pipeline is equipped in second water reserve, annular air pipeline is connect with air pressurized equipment, and the second water reserve is equipped with Clear water pipeline.

5. the Rain Garden system according to claim 4 for protecting bottom denitrification anaerobic area, it is characterised in that: described Annular air pipeline includes outer ring pipeline and inner ring pipeline, and inner ring pipeline is connected to outer ring pipeline by Internal and external cycle connecting tube, Several vent ports are uniformly provided on outer ring pipeline and inner ring pipeline.

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