CN105803892A - Method capable of being used for rain water seepage-filtering, collection and storage and purification in sponge city - Google Patents

Abstract

The invention discloses a method that can be used for percolation, storage and purification of rainwater in sponge cities. First, select a suitable location, excavate the bioretention tank foundation pit and storage well, and lay open edge stone belts at 5-10 cm on both sides of the bioretention tank road surface. The bioretention pond includes, from top to bottom, a crushed stone covering layer, a vegetation planting soil layer, a biochar filler layer and a gravel drainage layer, and an anti-seepage film is laid around and at the bottom. Lay the overflow pipe in the gravel drainage layer, the upper overflow port is 5~10 cm higher than the gravel cover layer, and the lower end is connected to the municipal drainage pipe network. The system can be used in residential areas, campuses, parking lots, parks, roads and other places. It can not only store rainwater, but also reduce the content of pollutants such as nitrogen, phosphorus, and heavy metals in rainwater, so as to achieve the purpose of reuse and finally effectively relieve urban pollution. prevent waterlogging and improve rainwater utilization efficiency.

Description

A method that can be used for rainwater infiltration, storage and purification in sponge cities

technical field

The invention belongs to the technical field of urban rainwater storage and purification, and specifically relates to the field of a rainwater infiltration, storage and purification multifunctional system that can be used in sponge cities.

technical background

Sponge city refers to a city that can be like a sponge and has good "elasticity" in adapting to environmental changes and responding to natural disasters. use. In recent years, with the frequent occurrence of extreme weather, waterlogging is common in many cities in my country after heavy rainfall. Recently, the concept of "sponge city" has attracted more and more attention in solving urban waterlogging, and has been written into construction plans one after another. In the past, the methods and ideas for controlling urban waterlogging in my country were relatively simple, focusing on the pursuit of large-area hardened pavement, adding and expanding infiltration facilities and underground drainage pipes, etc. Strong drainage of rainwater. In recent years, sunken greenbelts, infiltration ponds, wet ponds, etc. have begun to attract attention and have been rapidly constructed. However, due to the relatively single filler, although the infiltration of rainwater has been accelerated to a certain extent, it is difficult to effectively store rainwater and purify it. Take advantage of it. Therefore, the research and development of multifunctional devices and systems that can efficiently and continuously ensure rainwater infiltration, storage, purification, and reuse are particularly necessary for the construction of sponge cities.

Therefore, the present invention is a rainwater infiltration, storage and purification multifunctional system that can be used in sponge cities, which can effectively store urban rainwater and surface runoff, and purify rainwater at the same time, and finally can effectively alleviate urban waterlogging, save water resources, Improve rainwater utilization efficiency.

Contents of the invention

The purpose of the present invention is to provide a method that can be used for infiltration, storage and purification of rainwater in a sponge city, so as to solve the problem that urban rainwater is not easy to be accumulated and secondary pollution caused during the accumulation process. The ultimate purpose of the present invention is to store, purify and reuse urban rainwater or surface runoff, alleviate urban waterlogging, save water resources and improve rainwater utilization efficiency.

For solving above technical problem, the concrete technical scheme that the present invention adopts is as follows:

A method that can be used for rainwater infiltration, storage and purification in a sponge city is characterized in that it includes the following steps:

Step 1, make the rainwater under the sky first contact with the open edge stone belt and the gravel cover layer of the bioretention pond, so that the larger material is intercepted to obtain rainwater A;

Step 2, then make the rainwater A infiltrate into the vegetation planting soil layer to obtain the rainwater B which is initially purified;

Step 3, the rainwater B enters the biochar filler layer through the geotextile, and is accumulated and purified to obtain rainwater C;

Step 4, the rainwater C purified by the biochar filler layer enters the water storage well through the gravel drainage layer, thereby completing the infiltration, storage and purification of the rainwater under the sky.

The rainwater C can be used for spraying road surfaces, plants and cleaning vehicles.

When encountering rainstorm weather, part of the rainwater in the rainwater under the sky enters the municipal drainage pipe network through the overflow port through the overflow pipe.

The biochar filler layer includes a biochar filler device and biochar improved soil.

An overflow pipe is laid on the gravel drainage layer, the upper end is connected to the overflow port, and the lower end is connected to the municipal drainage pipe network.

A kind of multifunctional system that can be used for sponge city rainwater infiltration, storage and purification to realize the above method is characterized in that: it includes a bioretention tank and a water storage well;

The bioretention tank includes from top to bottom: gravel covering layer, vegetation planting soil layer, biochar filler layer and gravel drainage layer; at the same time, a 3-5cm anti-seepage film is laid around the interior of the bioretention tank and at the bottom The vegetation planting soil layer and the biochar filling layer are separated by geotextiles; water storage wells are respectively arranged on both sides of the bioretention tank, and the construction specifications and quantity of the water storage wells are based on local perennial rainfall or surface runoff and biological The construction scale of the detention pond is determined; the storage well is connected with the gravel drainage layer through underground pipelines, and is used to store purified rainwater.

The water storage well is used to store purified rainwater; the bioretention tank is connected to the water storage well; an open edge stone belt is laid at a distance of 5 to 10 cm from both sides of the road surface in the bioretention tank as the water inlet of the bioretention tank, At the same time, some larger substances (such as branches, plastic bags, etc.) are intercepted.

The soil in the vegetation planting soil layer is biochar-improved soil, that is, soil and biochar are fully mixed at a volume ratio of 9:1, and the thickness is 20-30 cm. The improved soil is easy to infiltrate rainwater on the one hand, and the other On the one hand, it is beneficial to the growth of plants; the biochar is prepared by burning rice husks, straws, weeds or forest leftovers at 300-600° C. in the absence of oxygen.

The thickness of the crushed stone covering layer is 3-5 cm, which is used to buffer the direct scouring effect of rainwater on the vegetation planting soil layer and the roots of the vegetation.

The biochar filling device is made of cement material, has good pressure bearing and pressure resistance, and is safe and reliable; the specification is: length×width×height=50cm×50cm×60cm, and the wall thickness is 3-5cm; 12 permeable round holes are evenly opened on the surface, the diameter of the permeable round holes is 8-10cm, and the center distance between adjacent permeable round holes is 15±1cm; the biochar filling device is filled with 42.2±8.1kg of biochar; at the same time, to prevent biochar particles Leak out from the permeable round hole, lay a layer of geotextile around the inside of the biochar filler device; the biochar filler device and the biochar improved soil with a thickness of 5-10cm are arranged at intervals.

The thickness of the gravel drainage layer is 10-20cm, and the overflow port at the upper end of the overflow pipe is 5-10cm higher than the gravel covering layer.

The process of rainwater filtration, storage and purification in the present invention is as follows: when the rainwater flows into the bioretention pond, it first contacts with the open edge stone belt and the gravel covering layer of the bioretention pond, and the larger matter is intercepted, and then the rainwater flows into the bioretention pond. Seep through the vegetation planting soil layer to obtain preliminary purification, and then pass through the geotextile and continue to pass through the biochar filler layer to completely accumulate and purify; after passing through the biochar filler layer, the rainwater enters the storage wells on both sides through the gravel drainage layer , The construction specifications and quantity of water storage wells should be determined according to the local annual rainfall or surface runoff and the construction scale of bioretention ponds. In case of heavy rain, part of the rainwater will enter the municipal drainage pipe network through the overflow port and the overflow pipe.

The rainwater purified by the invention can be used for spraying road surfaces, plants, cleaning vehicles and the like.

The invention has beneficial effects. The present invention adopts soil-plant-biochar combination technology, so that the system not only has good water storage performance, but also has high-efficiency, low-cost purification function; the present invention uses soil improved by biochar to make the soil layer The structure is more loose, on the one hand, it is beneficial to the infiltration of rainwater, and at the same time, the rainwater is initially purified, and the efficiency of further purification is improved; the present invention uses rainwater backflow and water storage system (water storage well), so that the purified rainwater can be used as Watering the road surface, cleaning vehicles and spraying vegetation, etc., have greatly improved the resource utilization efficiency of rainwater; the present invention adopts a modular biochar filling device, only needs to put an appropriate amount of biochar in the filling device, and then put the filling device The equidistant arrangement makes the operation simple and flexible, and it can be used immediately without any power, and has strong practicability; , the raw material is rich, and the cost is greatly reduced; the biochar used in the present invention as a filler not only has good adsorption performance, but also resists oxidation and decomposition, so that the biochar can be retained in the soil for decades or even hundreds of years , durable, but also greatly reduce system maintenance costs.

Description of drawings

Fig. 1 is the plane view of the system of the present invention

Fig. 2 is a side view of the system of the present invention

Fig. 3 is the front view of the system of the present invention

Fig. 4-1 is the biochar filling device diagram of the system of the present invention

Fig. 4-2 is the front view of the biochar filling device of the system of the present invention

Figure 4-3 is a side view of the biochar filling device of this system

Fig. 4-4 is the top view of the biochar filling device of the system of the present invention

In the figure, 1- ground, 2- opening edge stone belt, 3- bioretention tank, 4- biochar filling device, 5- biochar, 6- anti-seepage film, 7- storage well, 8- gravel covering layer , 9-vegetation planting soil layer, 10-geotextile, 11-gravel drainage layer, 12-overflow outlet, 13-overflow pipe connected to municipal drainage pipe network, 14-permeable small hole, 15-permeable round hole

detailed description

The following will help those skilled in the art understand the present invention more fully in conjunction with the accompanying drawings and specific embodiments, but the present invention is not limited thereto.

The present invention is a rainwater infiltration, storage and purification method that can be used in sponge cities. The system can be set up in residential areas, college campuses, parking lots, parks, roads, etc., and specifically includes the following steps:

Firstly, select a suitable low-lying position, excavate the bioretention pond 3 foundation pit and the water storage well 7 for storing purified rainwater;

(1) Lay open edge stone belts 2 at 5 to 10 cm from both sides of the road surface in the bioretention pond 3, which are the water inlet of the bioretention pond 3, and retain some larger materials (such as branches, plastic bags, etc.) at the same time;

(2) A 3-5 cm anti-seepage film 6 is laid around and at the bottom of the bioretention tank 3; the bioretention tank 3 is arranged sequentially from bottom to top: gravel drainage layer 11, biochar filler layer, and vegetation planting soil layer 9 and gravel overburden8;

(3) Lay a 10-20cm gravel drainage layer 11 on the anti-seepage film 6, and lay an overflow pipe on this layer at the same time. The upper end of the overflow port and the lower end are connected to the municipal drainage pipe network 13; the gravel drainage layer 11 communicates with the water storage well 3 through an underground pipeline;

(4) The biochar filler layer includes a biochar filler device 4 and a biochar-improved soil; the biochar filler device 4 is made of cement material, has good pressure bearing and pressure resistance, and is safe and reliable. The specifications are: length × width × height = 50cm × 50cm × 60cm, the wall thickness is 3-5cm; 12 permeable round holes 15 are evenly opened on each side of the biochar filling device 4, and the diameter of the permeable round holes (15) is 8-10cm , the distance between adjacent round holes is 15cm; the biochar filling device (4) is filled with 42.2 ± 8.1kg of biochar; at the same time, in order to prevent the biochar particles from leaking out of the water-permeable round hole 15, a bedding layer is placed around the inside of the biochar filling device 4 layer geotextile 10; the biochar filling device 4 is arranged at intervals with the biochar improved soil with a thickness of 5-10 cm;

(5) The biochar filling layer is separated from the vegetation planting soil layer 9 by a geotextile 10;

(6) laying biochar improved soil (volume ratio, soil: biochar=9:1, fully mixed) that thickness is 20～30cm in vegetation planting soil layer 9, and the soil after improvement is easy to infiltrate rainwater on the one hand, on the other hand conducive to the growth of plants;

(7) On the vegetation planting soil layer 9, a crushed stone covering layer 8 with a thickness of 3 to 5 cm is evenly laid to play a role in buffering rainwater.

The invention uses the adsorption and purification capabilities of plants, soil and biochar to comprehensively treat rainwater, and the process is as follows:

When the rainwater flows into the bioretention tank 3, it first contacts with the open edge stone belt 2 and the crushed stone covering layer 8, and larger substances are intercepted, and then the rainwater seeps down through the vegetation planting soil layer 9 to be initially purified, and through the geotextile 10 , and continue to pass through the biochar filler layer 4 to be completely accumulated and purified. After the biochar filler layer, the rainwater enters the water storage wells 7 on both sides through the gravel drainage layer 11. The construction specifications and quantity of the water storage wells 7 should be It is determined according to the local annual rainfall or surface runoff and the construction scale of the bioretention pond 3 . The purified rainwater can be used to spray roads, plants and clean vehicles, etc. In case of heavy rain, part of the rainwater will flow into the municipal drainage pipe network through the overflow port through the overflow pipe.

The biological bioretention pond 3 should be set at a relatively low terrain to ensure the infiltration, storage and purification of rainwater.

The number of plants to be planted can be determined according to the specifications of the actual construction of the bioretention tank. Plant species can be determined according to local climate conditions and ecological characteristics.

Rainwater treatment process:

Rainwater → open edge stone and crushed stone cover layer buffer → woody vegetation purification → biochar filler layer accumulation and repurification → gravel drainage layer → flow into municipal drainage pipe network or reservoir through overflow pipe → clean rainwater.

The above only expresses the implementation mode of the present invention, and has made a specific description, but it is not a limitation of the present invention. All modifications and improvements made within the spirit and principles of this creative idea should belong to the protection of this creative idea. scope.

Claims (5)

1. one kind can be used for sponge urban rainwater and oozes worry, harvests and the method purified, it is characterised in that comprise the following steps:

Step one, makes subaerial rainwater first contact with opening vertical curb band and biological delaying basin gravel mulch layer so that it is the material that middle volume is bigger obtains rainwater A after being intercepted；

Step 2, makes subsequently to ooze under rainwater A and plants soil layer to vegetation and obtain preliminary purification and obtain rainwater B；

Step 3, rainwater B enters charcoal packing layer through geotextiles, obtains rainwater C after accumulating and purify with being able to；

Step 4, the rainwater C after charcoal packing layer purifies is entered in water-retention well by gravel drainage blanket, thus completing oozing worry, harvest and purification subaerial rainwater.

2. a kind of sponge urban rainwater that can be used for according to claim 1 oozes worry, harvests and the method purified, it is characterised in that: described rainwater C can apply to spray road surface, plant and cleaning vehicle.

3. a kind of sponge urban rainwater that can be used for according to claim 1 oozes worry, harvests and the method purified, it is characterised in that: when running into rainstorm weather, in described subaerial rainwater, part rainwater is entered in municipal drainage pipe network through overflow pipe by overfall.

4. a kind of sponge urban rainwater that can be used for according to claim 1 oozes worry, harvests and the method purified, it is characterised in that: described charcoal packing layer includes charcoal filler device and charcoal improvement soil.

5. a kind of sponge urban rainwater that can be used for according to claim 1 oozes worry, harvests and the method purified, it is characterised in that: described gravel drainage blanket lays overflow pipe, and upper end connects overfall, lower end is connected to municipal drainage pipe network.