CN107143021B - A kind of biology delaying basin - Google Patents

Abstract

The present invention provides a bioretention pond, comprising: a crushed stone base layer is located at the bottom of the retention pond; a separation layer is located above the crushed stone base layer; an isolation component is located above the separation layer, and the isolation component is connected to the There is an included angle between the separation layers; the soil planting layer is located on one side of the isolation member, and the soil planting layer is filled with ordinary soil; the filter material layer is located on the other side of the partition plate, and the filter material layer It is used for seepage; wherein, the soil planting layer is a convex structure with high middle and low surrounding areas; in this way, the isolation component divides the bioretention pond into a drainage area and a planting area; when the rainfall is large, the soil planting layer is Convex structure with high middle and low surrounding, so the rainwater will flow to the outer filter material layer, and the rainwater will be filtered and infiltrated by the filter material layer to meet the drainage needs; in this way, the soil planting layer will not retain too much rainwater, ordinary soil The permeability is not large, so ordinary evergreen plants can be planted in the soil layer, which meets the needs of landscape.

Description

a bioretention pond

technical field

The invention belongs to the technical field of surface runoff treatment, and in particular relates to a biological retention pond.

Background technique

With the rapid development of society and economy, the problems of urban water safety and water environment are becoming more and more serious. To this end, the state proposes the strategy of building a sponge city. Sponge city refers to strengthening the management of urban planning and construction, giving full play to the absorption, infiltration and slow release of rainwater by ecosystems such as buildings, roads, green spaces, and water systems, effectively controlling rainwater runoff, and realizing natural accumulation, natural infiltration, and natural purification. A way of urban development.

Bioretention ponds are the main components of the green space system in sponge city construction, and are responsible for the important functions of rainwater storage and water purification. During heavy rains, the drainage time of the storage space on the surface of the bioretention tank is 12 to 24 hours, which requires high permeability of the planting soil layer to ensure normal drainage and avoid long-term flooding of plants. On the other hand, plant growth is closely related to the planting layer, and the high permeability of the planting layer will lead to a decrease in soil water retention, aggravation of water and fertilizer loss, and poor plant growth. Therefore, in existing bioretention systems, plant selection is often required to have good flood and drought tolerance. However, such plants have better landscape effects in their growth periods, such as spring and summer, while in their dormant periods, such as winter, the plants wither and the landscape effects are lost. On the other hand, although the general evergreen plants have good landscape effects, these plants are not very resistant to flooding and drought, and they also grow poorly in high-permeability soils and have a low survival rate. difficult to apply.

Based on this, the present invention provides a bioretention pond to solve the above problems in the prior art.

SUMMARY OF THE INVENTION

In view of the problems existing in the prior art, the embodiment of the present invention provides a bioretention pond, which is used to solve the problem in the prior art that during the construction of the sponge city, the plants in the bioretention pond are easily grown in the highly permeable soil. There is a phenomenon of dead seedlings, resulting in technical problems that drainage needs and landscape needs cannot coexist.

The present invention provides a biological retention pond, the retention pond includes:

Crushed stone base, located at the bottom of the retention pond;

a separation layer, located above the crushed stone base layer;

an isolation part, located above the isolation layer, and an included angle exists between the isolation part and the isolation layer;

a soil planting layer, located on one side of the isolation member, the soil planting layer is filled with ordinary soil;

The filter material layer is located on the other side of the isolation member, and the filter material layer is used for seepage; wherein, the soil planting layer is a convex structure with high middle and low surrounding.

In the above solution, the retention pond further comprises: a seepage pipe, the seepage pipe is installed at the bottom of the retention pond, and the distance between the seepage pipe and the bottom of the retention pond is 3-5 cm.

In the above solution, the filter material layer is filled with a metallurgical slag filter material with a thickness of 30-50 cm.

In the above solution, the retention pond further comprises: a cover layer, and the cover layer is located above the filter material layer.

In the above solution, the retention pond further comprises: a retention layer, and the retention layer is the space above the soil planting layer.

In the above solution, the isolation component includes: a partition plate or a partition fence.

In the above solution, the retention pond further comprises: an overflow well, one end of the overflow well is located at the bottom of the retention pond, and the other end of the overflow well is located at the top of the retention pond.

In the above solution, the retention tank further comprises: a filter cover installed on the other end of the overflow well.

In the above solution, the separation layer includes: permeable geotextile or coarse sand.

In the above solution, the retention tank further includes: a rainwater pipe, and the rainwater pipe is installed at 3-5 cm at the bottom of the overflow well.

The invention provides a bioretention pond, comprising: a crushed stone base layer, the crushed stone base layer is located at the bottom of the retention pond; a separation layer, the separation layer is located above the crushed stone base layer; an isolation part, the The isolation component is located above the isolation layer, and there is an included angle between the isolation component and the isolation layer; the soil planting layer is located on one side of the isolation component, and the soil planting layer is filled with soil There is ordinary soil; a filter material layer, the filter material layer is located on the other side of the separator, and the filter material layer is used for seepage; wherein, the planting soil layer is a convex structure with high middle and low surrounding; so , the isolation component divides the bioretention pond into a drainage area and a planting area; when the rainfall is large, because the soil planting layer is a convex structure with high middle and low surrounding, the rainwater will flow to the outer filter material layer, which will be filtered by the filter material layer. The material layer filters and infiltrates rainwater to meet the drainage needs; in this way, the soil planting layer will not retain too much rainwater, and the permeability of ordinary soil is not large. Therefore, ordinary evergreen plants can be planted in the planting soil layer, which meets the landscape requirements. need.

Description of drawings

1 is a schematic diagram of the overall structure of a bioretention pond provided by the present invention;

Figure 2 is a schematic diagram of the partial structure of the bioretention tank provided by the present invention.

Detailed ways

In order to solve the technical problem that in the prior art, during the construction of the sponge city, the plants in the bioretention ponds are prone to die seedlings when they grow in the highly permeable soil, resulting in the inability to coexist drainage requirements and landscape requirements, the present invention provides A bioretention pond, comprising: a crushed stone base layer, the crushed stone base layer is located at the bottom of the retention pond; a separation layer, the separation layer is located above the crushed stone base layer; an isolation part, the isolation part is located on the Above the separation layer, there is an included angle between the separation member and the separation layer; a soil planting layer, the soil planting layer is located on one side of the separation member, and the soil planting layer is filled with ordinary soil; filter material The filter material layer is located on the other side of the separator, and the filter material layer is used for seepage; wherein, the soil planting layer is a convex structure with high middle and low surrounding.

The technical solutions of the present invention will be further described in detail below through the accompanying drawings and specific embodiments.

This embodiment provides a bioretention pond. The shape of the bioretention pond can be a square, a circle or other irregular shapes. The bioretention pond is shown in FIG. 1 , and the bioretention pond includes: crushed stone Base layer 1, separation layer 2, isolation part 3, soil planting layer 4, filter material layer 5; wherein,

The crushed stone base layer 1 is located at the bottom of the retention pond and is used for load bearing and infiltration of water flow; the thickness of the crushed stone base layer is 20-30 cm, and the crushed stone can be open-graded crushed stone, and the crushing value is less than or equal to 25 %; the particle size of the crushed stone is 5-25 mm.

The separation layer 2 is located above the gravel base layer 1; the separation layer 2 may be a permeable geotextile or a coarse sand layer, and the thickness of the coarse sand layer may be 3-5 cm.

The spacer member 3 is located above the spacer layer 2, and an included angle exists between the spacer member 3 and the spacer layer 2; the included angle may be 45° to 90°, preferably 90°. Soil planting layer 4 and filter material layer 5 can be separated.

Here, the isolation member 2 may be a plurality of wooden partitions or a wooden fence, and the isolation member 3 is arranged along the retention pond for a week; wherein, the thickness of the wooden partitions is 2-3 cm, so The wooden fence can be a fence composed of cylindrical wood. In order to improve the aesthetics, the height of the isolation member 2 is also 1-2 cm higher than the edge of the soil planting layer 4 .

The soil planting layer 4 is located on one side of the isolation member 3, and the soil planting layer is filled with ordinary soil for planting landscape plants; the soil planting layer 4 is a convex structure with a high middle and low surrounding areas. The difference in elevation between the highest point at the top of the soil planting layer 4 and the lowest point in the edge is 3 to 5 cm.

The filter material layer 5 is located on the other side of the isolation member 2, and the filter material layer is used for seepage; the filter material layer 5 is filled with a metallurgical slag filter material with a thickness of 30-50 cm, and the filter material layer 5 The width of the sideband is 5-15cm. The metallurgical slag filter material is processed from solid waste discharged from iron and steel metallurgical enterprises, and the metallurgical slag filter material has a porous particle structure, and its permeability coefficient is 1.16×10 ^-5 to 5.79×10 ^-5 m/s; The metallurgical slag filter material has a certain degree of alkalinity, and can have a good removal effect on pollutants such as suspended solids and heavy metals in rainwater.

When determining the permeability v of the rate material layer 5, it can be determined by formula (1):

In formula (1), the P is the catchment area served by the bioretention pond, the h is the rainfall converted from the total runoff control rate, and the t is the emptying time of the bioretention pond; the a is the perimeter of the bioretention tank, and b is the width of the filter material layer 5 .

In this way, the isolation part 2 divides the bioretention pond into a drainage area and a planting area; when the rainfall is large, since the soil planting layer 4 is a convex structure with high middle and low surrounding, the rainwater will flow to the outer filter material layer 5. The rainwater is filtered and infiltrated by the filter material layer 5 to meet the drainage needs; in this way, the soil planting layer 4 will not retain too much rainwater, and the penetration of ordinary soil is not large, so the soil planting layer 4 can be planted with ordinary four-season crops. Green plants meet the needs of landscape.

Here, in order to protect the filter material layer, the retention tank further includes: a cover layer 6 , and the cover layer 6 is located above the filter material layer 5 . The covering layer 6 may include: pebbles or ceramsite, the thickness of the covering layer 6 is 5-10 cm; the particle size of the pebbles is 10-25 mm.

In order to retain rainwater, the retention pond further includes: a retention layer 7, which is a space above the soil planting layer 4, and the space is specifically a concave water storage area relative to the surrounding ground. The depth of the area is 10 to 30 cm.

Referring to Fig. 2, the height of the retention layer 7 can be determined by formula (2):

In formula (2), the p ₁ is the area of the bioretention pond.

Then, the height difference d between the top of the cover layer at the edge of the bioretention pond and the surrounding road is determined by formula (3):

d=d ₁ +D+d ₂ (3)

In formula (3), the d ₁ is the height difference between the top of the soil planting layer and the surrounding lowest point, and the d ₂ is the height difference between the top of the overflow well 9 and the surrounding roads.

Further, in order to discharge the treated rainwater out of the retention pond, referring to FIG. 1 , the retention pond further includes: a seepage pipe 8 , the seepage pipe 8 is installed at the bottom of the retention pond, and the seepage pipe 8 is connected to the The distance from the bottom of the retention tank is 3 to 5 cm. The infiltration pipe 8 can be a plastic infiltration pipe, a cement infiltration pipe or a stainless steel infiltration pipe; the infiltration pipe 8 is provided with a plurality of perforations, and the opening position of the perforation is 45° obliquely downward, and the spacing between the perforations is 8 to 15cm.

In order to deal with the rainstorm situation, the detention pond further includes: an overflow well 9 and a rainwater pipe 10, the overflow well 9 is made of concrete, one end of the overflow well 9 is located at the bottom of the detention pond, and the The bottom is flush; the other end of the overflow well 9 is at the top of the retention pond. Specifically, the height of one end of the overflow well 9 is determined according to the area of the catchment zone served by the bioretention pool and the volume of the retention layer 7. Generally speaking, the height of one end of the overflow well 9 needs to be lower than the surrounding road surface 5～10cm.

The rainwater pipe 10 is installed at 3-5 cm at the bottom of the overflow well, and the rainwater pipe 10 is also connected with the seepage pipe 8 for discharging seepage into the municipal pipe network.

Here, the retention tank further includes a filter cover installed at the other end of the overflow well 9 . Specifically, the filter cover may be a rainwater grate.

Example 1

In practical application, this embodiment builds a new bioretention pond in the transformation area, and the water storage capacity of the bioretention pond is 0.75m ³ ; the specific implementation is as follows:

Excavate a square foundation pit with a length of 3m and a width of 2m and a depth of about 97.5cm in the reconstruction area, and lay impermeable geotextiles around and at the bottom of the foundation pit; the bioretention pond includes: gravel base 1, separation layer 2, isolation parts 3. Soil planting layer 4, filter material layer 5; among them,

The crushed stone base layer 1 is located at the bottom of the retention pond and is used for bearing load and infiltration of water flow; the thickness of the crushed stone base layer is 30cm, and the crushed stone can be open-graded crushed stone, and the crushing value is less than or equal to 25%; The particle size of the crushed stone is 5-25 mm.

The separation layer 2 is located above the gravel base layer 1; the separation layer 2 may be a permeable geotextile or a coarse sand layer, and the thickness of the coarse sand layer may be 4 cm.

The isolation member 3 is located above the isolation layer 2, and there is an included angle between the isolation member 3 and the isolation layer 2; the included angle is 90 ^° . Soil planting layer 4 and filter material layer 5 can be separated.

In this embodiment, the isolation member 2 is a plurality of wooden clapboards, and the isolation member 3 is arranged along the retention tank for a week; wherein, the thickness of the wooden clapboard is 2cm, 46cm long, and 20cm wide; and The partition plate is about 10 cm away from the periphery of the bioretention tank; in order to improve the aesthetics, the height of the isolation member 2 is also 1-2 cm higher than the edge of the planting soil layer 4 .

The soil planting layer 4 is located on one side of the isolation member 3, and the soil planting layer is filled with ordinary soil for planting landscape plants; the soil planting layer 4 is a convex structure with a high middle and low surrounding areas. The height of the soil planting layer 4 is 50 cm.

The filter material layer 5 is located on the other side of the isolation member 2, and the filter material layer is used for seepage; the filter material layer 5 is filled with a metallurgical slag filter material with a thickness of 40 cm, and the edge of the filter material layer 5 is The belt width is 10cm. The metallurgical slag filter material is processed from solid waste discharged from iron and steel metallurgical enterprises, and the metallurgical slag filter material has a porous particle structure with a permeability coefficient of 1.89×10 ^-5 m/s; the metallurgical slag filter material has A certain degree of alkalinity can effectively remove pollutants such as suspended solids and heavy metals in rainwater.

When determining the permeability v of the rate material layer 5, it can be determined by formula (1):

In formula (1), the P is the catchment zone area served by the bioretention pond, and in this embodiment, P is 30 m ² ; the h is the rainfall converted from the total runoff control rate, and the h is 25 mm ; the t is the emptying time of the bioretention tank; the t is 12-24h; the a is the circumference of the bioretention tank, the length of the bioretention tank is 3m, the width is 2m; the b is The width of the filter material layer 5, the b is 10cm. The permeability coefficient finally calculated is 1.45×10 ^-5 ~ 2.89×10 ^-5 m/s, so the selected metallurgical slag filter material permeability coefficient meets the drainage requirements.

In this way, the isolation part 2 divides the bioretention pond into a drainage area and a planting area; when the rainfall is large, since the soil planting layer 4 is a convex structure with high middle and low surrounding, the rainwater will flow to the outer filter material layer 5. The rainwater is filtered and infiltrated by the filter material layer 5 to meet the drainage needs; in this way, the soil planting layer 4 will not retain too much rainwater, and the penetration of ordinary soil is not large, so the soil planting layer 4 can be planted with ordinary four-season crops. Green plants meet the needs of landscape.

Here, in order to protect the filter material layer, the retention tank further includes: a cover layer 6 , and the cover layer 6 is located above the filter material layer 5 . The covering layer 6 includes: a pebble layer, the thickness of the covering layer 6 is 5 cm; the particle size of the pebble is 10-25 mm.

In order to retain rainwater, the retention pond further includes: a retention layer 7, which is a space above the soil planting layer 4, and the space is specifically a concave water storage area relative to the surrounding ground. The depth of the area is 12.5 cm.

Referring to Fig. 2, the height of the retention layer 7 can be determined by formula (2):

In formula (2), the p ₁ is the area of the bioretention pond.

Then, the height difference d between the top of the cover layer at the edge of the bioretention pond and the surrounding road is determined by formula (3):

d=d ₁ +D+d ₂ (3)

In formula (3), the d ₁ is the height difference between the top of the soil planting layer and the surrounding lowest point, the d ₁ is 5 cm, the d ₂ is the height difference between the top of the overflow well 9 and the surrounding roads, and the d ₁ is 5cm.

Further, in order to discharge the treated rainwater out of the retention pond, referring to FIG. 1 , the retention pond further includes: a seepage pipe 8 , the seepage pipe 8 is installed at the bottom of the retention pond, and the seepage pipe 8 is connected to the The distance from the bottom of the retention pond was 4 cm. The infiltration pipe 8 is a plastic infiltration pipe; a plurality of perforations are arranged on the infiltration pipe 8 , the opening position of the perforation is 45° obliquely downward, and the distance between the perforations is 10 cm.

In order to deal with the rainstorm situation, the detention pond further includes: an overflow well 9 and a rainwater pipe 10, the overflow well 9 is made of concrete, one end of the overflow well 9 is located at the bottom of the detention pond, and the The bottom is flush; the other end of the overflow well 9 is at the top of the retention pond. Specifically, the height of one end of the overflow well 9 is determined according to the area of the catchment zone served by the bioretention pool and the volume of the retention layer 7. Generally speaking, the height of one end of the overflow well 9 needs to be lower than the surrounding road surface 5cm.

The rainwater pipe 10 is installed at the bottom 4 cm of the overflow well, and the rainwater pipe 10 is also connected with the seepage pipe 8 for discharging seepage into the municipal pipe network.

Here, the retention tank further includes a filter cover installed at the other end of the overflow well 9 . Specifically, the filter cover may be a rainwater grate.

Embodiment 2

In practical application, this embodiment builds a new bioretention pond in the transformation area, and the water storage capacity of the bioretention pond is 0.9m ³ ; the specific implementation is as follows:

Excavate a circular foundation pit with a radius of 1m and a depth of about 102cm in the transformation area, and lay impermeable geotextiles around and at the bottom of the foundation pit; the bioretention pond includes: gravel base 1, separation layer 2, isolation parts 3, planting Soil layer 4, filter material layer 5; wherein,

The crushed stone base layer 1 is located at the bottom of the retention pond and is used for load-bearing and permeation of water flow; the thickness of the crushed stone base layer is 25cm, and the crushed stone can be open-graded crushed stone, and the crushing value is less than or equal to 25%; The particle size of the crushed stone is 5-25 mm.

The separation layer 2 is located above the crushed stone base layer 1; the separation layer 2 is a water-permeable geotextile.

The spacer member 3 is located above the spacer layer 2, and there is an included angle between the spacer member 3 and the spacer layer 2; the included angle is 90°. Soil planting layer 4 and filter material layer 5 can be separated.

In this embodiment, the isolation member 2 is a plurality of wooden partitions, and the isolation member 3 is arranged along the retention tank for a week; wherein, the thickness of the wooden partition is 2cm, 41cm long, and 20cm wide; and The separator is about 15 cm away from the periphery of the bioretention tank; in order to improve the aesthetics, the height of the isolation member 2 is also 1-2 cm higher than the edge of the planting soil layer 4 .

The soil planting layer 4 is located on one side of the isolation member 3, and the soil planting layer is filled with ordinary soil for planting landscape plants; the soil planting layer 4 is a convex structure with a high middle and low surrounding areas. The height of the soil planting layer 4 is 43 cm.

The filter material layer 5 is located on the other side of the isolation member 2, and the filter material layer is used for seepage; the filter material layer 5 is filled with a metallurgical slag filter material with a thickness of 35 cm, and the edge of the filter material layer 5 is The belt width is 15cm. The metallurgical slag filter material is processed from solid waste discharged from iron and steel metallurgical enterprises, and the metallurgical slag filter material has a porous particle structure with a permeability coefficient of 2.48×10 ^-5 m/s; the metallurgical slag filter material has A certain degree of alkalinity can effectively remove pollutants such as suspended solids and heavy metals in rainwater.

When determining the permeability v of the rate material layer 5, it can be determined by formula (1):

In formula (1), the P is the catchment zone area served by the bioretention pond, and in this embodiment, P is 30 m ² ; the h is the rainfall converted from the total runoff control rate, and the h is 30 mm ; the t is the emptying time of the bioretention tank; the t is 12 to 24 hours; the a is the circumference of the bioretention tank, and the radius of the bioretention tank is 1 m; the b is the filter material layer 5 width, the b is 15cm. The final calculated permeability coefficient is 1.38×10 ^-5 to 2.76×10 ^-5 m/s, so the selected metallurgical slag filter material permeability coefficient meets the drainage requirement.

In this way, the isolation part 2 divides the bioretention pond into a drainage area and a planting area; when the rainfall is large, since the soil planting layer 4 is a convex structure with high middle and low surrounding, the rainwater will flow to the outer filter material layer 5. The rainwater is filtered and infiltrated by the filter material layer 5 to meet the drainage needs; in this way, the soil planting layer 4 will not retain too much rainwater, and the penetration of ordinary soil is not large, so the soil planting layer 4 can be planted with ordinary four-season crops. Green plants meet the needs of landscape.

Here, in order to protect the filter material layer, the retention tank further includes: a cover layer 6 , and the cover layer 6 is located above the filter material layer 5 . The covering layer 6 includes: a pebble layer, the thickness of the covering layer 6 is 5 cm; the particle size of the pebble is 10-25 mm.

In order to retain rainwater, the retention pond further includes: a retention layer 7, the retention layer 7 is the space above the soil planting layer 4, and the space is specifically a concave water storage area relative to the surrounding ground.

Referring to Fig. 2, the height of the retention layer 7 can be determined by formula (2):

In formula (2), the p ₁ is the area of the bioretention pond.

Then, the height difference d between the top of the cover layer at the edge of the bioretention pond and the surrounding road is determined by formula (3):

d=d ₁ +D+d ₂ (3)

In formula (3), the d ₁ is the height difference between the top of the soil planting layer and the surrounding lowest point, the d ₁ is 3 cm, the d ₂ is the height difference between the top of the overflow well 9 and the surrounding roads, and the d ₁ is 5cm.

Further, in order to discharge the treated rainwater out of the retention pond, referring to FIG. 1 , the retention pond further includes: a seepage pipe 8 , the seepage pipe 8 is installed at the bottom of the retention pond, and the seepage pipe 8 is connected to the The distance from the bottom of the retention tank was 5 cm. The infiltration pipe 8 is a plastic infiltration pipe; a plurality of perforations are arranged on the infiltration pipe 8 , the opening position of the perforation is 45° obliquely downward, and the distance between the perforations is 10 cm.

In order to deal with the rainstorm situation, the detention pond further includes: an overflow well 9 and a rainwater pipe 10, the overflow well 9 is made of concrete, one end of the overflow well 9 is located at the bottom of the detention pond, and the The bottom is flush; the other end of the overflow well 9 is at the top of the retention pond. Specifically, the height of one end of the overflow well 9 is determined according to the area of the catchment zone served by the bioretention pool and the volume of the retention layer 7. Generally speaking, the height of one end of the overflow well 9 needs to be lower than the surrounding road surface 5cm.

The rainwater pipe 10 is installed at the bottom 5 cm of the overflow well, and the rainwater pipe 10 is also connected with the seepage pipe 8 for discharging seepage into the municipal pipe network.

Here, the retention tank further includes a filter cover installed at the other end of the overflow well 9 . Specifically, the filter cover may be a rainwater grate.

Embodiment 3

In practical application, this embodiment builds a new bioretention pond in the transformation area, and the water storage capacity of the bioretention pond is 0.7m ³ ; the specific implementation is as follows:

Excavate a equilateral triangle foundation pit with a side length of 4m and a depth of 90cm in the reconstruction area, and lay impermeable geotextiles around and at the bottom of the foundation pit; the bioretention pond includes: gravel base 1, separation layer 2, isolation parts 3, Planting soil layer 4, filter material layer 5; wherein,

The crushed stone base layer 1 is located at the bottom of the retention pond and is used for load bearing and infiltration of water flow; the thickness of the crushed stone base layer is 20cm, and the crushed stone can be open-graded crushed stone, and the crushing value is less than or equal to 25%; The particle size of the crushed stone is 5-25 mm.

The separation layer 2 is located above the crushed stone base layer 1; the separation layer 2 is a water-permeable geotextile.

The isolation member 3 is located above the isolation layer 2, and an included angle exists between the isolation member 3 and the isolation layer 2; the included angle is 90°. Soil planting layer 4 and filter material layer 5 can be separated.

In this embodiment, the isolation member 2 is a plurality of wooden clapboards, and the isolation member 3 is arranged along the retention tank for a week; wherein, the thickness of the wooden clapboard is 2cm, 40cm long, and 20cm wide; and The separator is about 15 cm away from the periphery of the bioretention tank; in order to improve the aesthetics, the height of the isolation member 2 is also 1-2 cm higher than the edge of the planting soil layer 4 .

The soil planting layer 4 is located on one side of the isolation member 3, and the soil planting layer is filled with ordinary soil for planting landscape plants; the soil planting layer 4 is a convex structure with a high middle and low surrounding areas. The height of the soil planting layer 4 is 44 cm.

The filter material layer 5 is located on the other side of the isolation member 2, and the filter material layer is used for seepage; the filter material layer 5 is filled with a metallurgical slag filter material with a thickness of 36 cm, and the edge of the filter material layer 5 is The belt width is 8cm. The metallurgical slag filter material is processed from solid waste discharged from iron and steel metallurgical enterprises, and the metallurgical slag filter material has a porous particle structure with a permeability coefficient of 1.23×10 ^-5 m/s; the metallurgical slag filter material has A certain degree of alkalinity can effectively remove pollutants such as suspended solids and heavy metals in rainwater.

When determining the permeability v of the rate material layer 5, it can be determined by formula (1):

In formula (1), the P is the area of the catchment zone served by the bioretention pond, and in this embodiment, P is 35 m ² ; the h is the rainfall converted from the total runoff control rate, and the h is 20 mm ; the t is the emptying time of the bioretention tank; the t is 12-24h; the a is the circumference of the bioretention tank, and the side length of the bioretention tank is 4m; the b is the filter material layer 5 width, the b is 8cm. The permeability coefficient finally calculated is 8.44×10 ^-6 ~ 1.69×10 ^-5 m/s, so the selected metallurgical slag filter material permeability coefficient meets the drainage requirements.

In this way, the isolation part 2 divides the bioretention pond into a drainage area and a planting area; when the rainfall is large, since the soil planting layer 4 is a convex structure with high middle and low surrounding, the rainwater will flow to the outer filter material layer 5. The rainwater is filtered and infiltrated by the filter material layer 5 to meet the drainage needs; in this way, the soil planting layer 4 will not retain too much rainwater, and the penetration of ordinary soil is not large, so the soil planting layer 4 can be planted with ordinary four-season crops. Green plants meet the needs of landscape.

Here, in order to protect the filter material layer, the retention tank further includes: a cover layer 6 , and the cover layer 6 is located above the filter material layer 5 . The covering layer 6 includes: a pebble layer, the thickness of the covering layer 6 is 3 cm; the particle size of the pebble is 10-25 mm.

In order to retain rainwater, the retention pond further includes: a retention layer 7, the retention layer 7 is the space above the soil planting layer 4, and the space is specifically a concave water storage area relative to the surrounding ground.

Referring to Fig. 2, the height of the retention layer 7 can be determined by formula (2):

In formula (2), the p ₁ is the area of the bioretention pond.

Then, the height difference d between the top of the cover layer at the edge of the bioretention pond and the surrounding road is determined by formula (3):

d=d ₁ +D+d ₂ (3)

In formula (3), the d ₁ is the height difference between the top of the soil planting layer and the surrounding lowest point, the d ₁ is 5 cm, the d ₂ is the height difference between the top of the overflow well 9 and the surrounding roads, and the d ₁ is 6cm.

Further, in order to discharge the treated rainwater out of the retention pond, referring to FIG. 1 , the retention pond further includes: a seepage pipe 8 , the seepage pipe 8 is installed at the bottom of the retention pond, and the seepage pipe 8 is connected to the The distance from the bottom of the retention pond was 3.5 cm. The infiltration pipe 8 is a plastic infiltration pipe; a plurality of perforations are arranged on the infiltration pipe 8 , the opening position of the perforation is 45° obliquely downward, and the distance between the perforations is 10 cm.

In order to deal with the rainstorm situation, the detention pond further includes: an overflow well 9 and a rainwater pipe 10, the overflow well 9 is made of concrete, one end of the overflow well 9 is located at the bottom of the detention pond, and the The bottom is flush; the other end of the overflow well 9 is at the top of the retention pond. Specifically, the height of one end of the overflow well 9 is determined according to the area of the catchment zone served by the bioretention pool and the volume of the retention layer 7. Generally speaking, the height of one end of the overflow well 9 needs to be lower than the surrounding road surface 6cm.

The rainwater pipe 10 is installed at the bottom 4.5 cm of the overflow well, and the rainwater pipe 10 is also connected with the seepage pipe 8 for discharging seepage into the municipal pipe network.

Here, the retention tank further includes a filter cover installed at the other end of the overflow well 9 . Specifically, the filter cover may be a rainwater grate.

The beneficial effects that the bioretention pond provided in the embodiment of the present invention can bring are at least:

The invention provides a bioretention pond, the system comprising: a crushed stone base layer, the crushed stone base layer is located at the bottom of the retention pond; a separation layer, the separation layer is located above the crushed stone base layer; an isolation component, The isolation component is located above the isolation layer, and there is an included angle between the isolation component and the isolation layer; the soil planting layer is located on one side of the isolation component, and the soil planting layer is located at one side of the isolation component. Filled with ordinary soil; filter material layer, the filter material layer is located on the other side of the partition plate, and the filter material layer is used for seepage; wherein, the planting soil layer is a convex structure with high middle and low surrounding; In this way, the isolation component divides the bioretention pond into a drainage area and a planting area; since the soil planting layer is a convex structure with a high middle and low surrounding areas, the rainwater will flow to the outer filter material layer, and the rainwater will be treated by the filter material layer. Filtration and infiltration meet the drainage needs; and the filter material layer and the soil are set separately, without mutual interference, and the filter material layer can be recycled and replaced regularly, which is convenient for maintenance and does not damage the plants; in this way, the soil planting layer will not be retained There is too much rain, and the penetration of ordinary soil is not large, so ordinary evergreen plants can be planted in the soil layer, which expands the planting range and meets the needs of landscape; When the plants are usually sprinkled and maintained, only the planting area is sprinkled with a small amount of water, and the water remains in the planting soil layer and slowly infiltrates to nourish the plants; when it rains lightly, the water on the road flows into the edge of the bioretention pond and infiltrates directly; When the rain is heavy, the rainwater can fill the stagnant layer through the overflow; when it rains heavily, the rainwater that exceeds the standard is discharged through the overflow well. Further, because the planted soil layer only undertakes a small amount of infiltration function (not considered in the calculation of drainage), it is beneficial to reduce the impact of the rainwater infiltration process on the native soil ecosystem, and is conducive to maintaining the ecological balance of the native soil, making the bioretention pond more suitable for Sponge cities use native plants and the idea of low-impact development.

The above are only preferred embodiments of the present invention, and are not intended to limit the protection scope of the present invention. Any modifications, equivalent replacements and improvements made within the spirit and principles of the present invention shall be included in the within the protection scope of the present invention.

Claims (7)

1. A bioretention tank characterised in that the tank includes:

the gravel base layer is positioned at the bottom of the retention pool;

a spacer layer located above the crushed stone base layer;

the isolation component is positioned above the separation layer, and an included angle is formed between the isolation component and the separation layer;

the planting soil layer is positioned on one side of the isolation component and is filled with common soil;

the filter material layer is positioned on the other side of the isolation component and is used for seepage; wherein the planting soil layer is of a convex structure with a high middle part and a low periphery;

the seepage pipe is arranged at the bottom of the retention pool, and the distance between the seepage pipe and the bottom of the retention pool is 3-5 cm;

the retention tank further comprises: one end of the overflow well is positioned at the bottom of the retention tank, and the other end of the overflow well is positioned at the top of the retention tank;

the retention tank further comprises: and the rainwater pipe is arranged at the position of 3-5 cm at the bottom of the overflow well.

2. The retention pond according to claim 1, wherein the filter material layer is filled with a metallurgical slag filter material with a thickness of 30-50 cm.

3. The retention tank of claim 1, further comprising: a cover layer located over the frit layer.

4. The retention tank of claim 1, further comprising: the detention layer is the space above the planting soil layer.

5. The retention tank of claim 1, wherein the partition member includes: a baffle or a dividing fence.

6. The retention tank of claim 1, further comprising: and the filter cover is arranged at the other end of the overflow well.

7. A retention tank according to claim 1, wherein the separation layer comprises: permeable geotextile or coarse sand.