阅读说明：本技术 一种导流式固定化微生物耦合型的植草沟 (Flow guide type immobilized microorganism coupling type grass planting ditch ) 是由 王蔚卿 周烨 谢予婕 肖峻 刘曦 黄建乐 杨阳 胡君 蒋加莉 杨燕华 于 2019-10-25 设计创作，主要内容包括：本发明公开一种导流式固定化微生物耦合型的植草沟,属于生态水处理设施的技术领域,包括：植草沟本体和固定化微生物处理单元,导流式固定化微生物处理单元包括：一导流管组,导流管组设于植草沟本体内；若干固定化微生物模块,若干固定化微生物模块均设于导流管组内；若干液位观察管,若干液位观察管的下端均伸入植草沟本体内,且均与导流管组相连通；一排水管,排水管与导流管组的一端相连通。本发明能够充分利用植草沟的地下空间,将植草沟内直接排入下游的表面径流道路地下管路系统,并利用管路系统内的固定化微生物,对其进行深度净化,从而实现在较小土地占用面积的情况下,满足地块对雨水径流的截流、输送及净化的需求。(The invention discloses a flow-guiding immobilized microorganism coupling type grass planting ditch, which belongs to the technical field of ecological water treatment facilities and comprises the following components: grass planting ditch body and immobilized microorganism processing unit, the immobilized microorganism processing unit of water conservancy diversion formula includes: the guide pipe group is arranged in the grass planting ditch body; the immobilized microorganism modules are all arranged in the guide pipe group; the lower ends of the liquid level observation pipes extend into the grass planting ditch body and are communicated with the guide pipe group; and the drain pipe is communicated with one end of the guide pipe group. The invention can fully utilize the underground space of the grass planting ditch, directly discharge the grass planting ditch into the downstream surface runoff road underground pipeline system, and deeply purify the surface runoff road underground pipeline system by utilizing the immobilized microorganisms in the pipeline system, thereby meeting the requirements of the land for intercepting, conveying and purifying the rainwater runoff under the condition of smaller land occupation area.)

1. A grass planting ditch of water conservancy diversion formula immobilized microorganism coupling type which characterized in that includes: grass planting ditch body and immobilized microorganism processing unit, the immobilized microorganism processing unit of water conservancy diversion formula includes:

the guide pipe group is arranged in the grass planting ditch body;

the plurality of immobilized microorganism modules are arranged in the guide pipe group and are used for fully immobilizing, converting and degrading various organic and inorganic pollutants in the runoff of rainwater;

the lower ends of the liquid level observation pipes extend into the grass planting ditch body and are communicated with the guide pipe groups, and the liquid level observation pipes are used for periodically detecting the water level condition in the guide pipe groups;

and the drain pipe is communicated with one end of the guide pipe group and used for purifying the rainwater into a municipal rainwater pipeline.

2. The flow-guided immobilized microorganism coupled grass-planting trench of claim 1, wherein the flow-guided tube group comprises: the plurality of guide pipes are arranged in the grass planting ditch body, one ends of the plurality of guide pipes are respectively communicated with the drainage pipe, the immobilized microorganism modules are respectively arranged in the plurality of guide pipes, and the liquid level observation pipes are respectively communicated with the plurality of guide pipes.

3. The flow-guided immobilized microorganism coupled grass-planting trench of claim 2, wherein each immobilized microorganism module comprises: pipeline inner skleeve and immobilized microorganism, the pipeline inner skleeve is located in the water conservancy diversion pipe, immobilized microorganism locates in the pipeline inner skleeve, the pipeline inner skleeve is the confined cylinder configuration, a plurality of through-holes have been seted up on the surface of pipeline inner skleeve, be equipped with the geotechnological cloth that permeates water in the pipeline inner skleeve.

4. The flow-guiding immobilized microorganism coupled grass planting ditch of claim 3, wherein each flow-guiding pipe comprises a flow-guiding water inlet end, a flow-guiding middle section and a flow-guiding water outlet end, the liquid level observation pipe is connected to the flow-guiding middle section, the immobilized microorganism module is disposed in the flow-guiding middle section, and the end of the flow-guiding water outlet end far away from the flow-guiding middle section is connected to the water outlet pipe.

5. The flow-guiding immobilized microorganism coupled grass planting ditch of claim 4, wherein the grass planting ditch body comprises a drainage layer, a planting soil layer and a stagnant water layer which are sequentially arranged from bottom to top, the flow-guiding water inlet end is located in the stagnant water layer, the flow-guiding middle section, the flow-guiding water outlet end and the drainage pipe are all located in the planting soil layer, and the upper end of the liquid level observation pipe is higher than the upper surface of the stagnant water layer.

6. The flow-guiding immobilized microorganism coupled grass planting ditch of claim 5, wherein two overflow weirs are arranged in the stagnant water layer, the lower surfaces of the two overflow weirs are against the upper surface of the planting soil layer, a plurality of flow-guiding water inlet ends are arranged in one overflow weir, and the bottoms of the flow-guiding water inlet ends are flush with the bottom of the one overflow weir.

7. The flow-guiding immobilized microorganism coupled grass planting ditch of claim 6, wherein the grass planting ditch is arranged under the ground, the surface layer of the ground is a plain soil foundation, the grass planting ditch comprises a grass planting ditch body and an impermeable membrane, and the impermeable membrane is arranged between the plain soil foundation and the grass planting ditch body.

8. The flow-guiding immobilized microorganism coupled grass planting ditch of claim 7, wherein an overflow catch basin is disposed in the grass planting ditch, the lower end of the overflow catch basin is disposed in the soil foundation, the upper end of the overflow catch basin sequentially penetrates through the drainage layer and the planting soil layer from bottom to top and extends into the stagnant water layer, the upper end of the overflow catch basin is provided with an overflow gully, the overflow gully is flush with the upper surface of the stagnant water layer, and the drainage pipe is communicated with the overflow catch basin.

9. The flow-guiding immobilized microorganism coupled grass-planting trench of claim 8, wherein a perforated water-collecting pipe is arranged in the drainage layer, and one end of the perforated water-collecting pipe is communicated with the overflow catch basin.

10. The flow-guiding immobilized microorganism coupled grass planting ditch of claim 5, wherein the permeable geotextile is arranged between the drainage layer and the planting soil layer.

Technical Field

The invention relates to the technical field of ecological water treatment facilities, in particular to a flow guide type immobilized microorganism coupling type grass planting ditch.

Background

The grass planting ditch is used as an ecological water treatment facility and is widely applied to interception and transfer of ground rainwater runoff in a sponge urban system. However, while the runoff transferring function of the various types of grass planting ditches is exerted, no obvious function is used in the aspects of reduction of runoff pollutant load and corresponding water quality purification, so that the potential role of the grass planting ditches in regional runoff control and water environment treatment is limited. The immobilized microorganism technology utilizes the metabolism function of microorganisms to absorb, assimilate and convert pollutants in the surrounding water body and provide water quality of the water body by arranging an immobilized carrier containing engineering microorganisms in a matrix or the water body, but the immobilized microorganism technology is not mature and applied in grass planting ditches at present.

Disclosure of Invention

Aiming at the problems of the prior grass planting ditch, the invention aims to provide a flow-guiding type immobilized microorganism coupling type grass planting ditch, which can fully utilize the underground space of the grass planting ditch, guide the surface runoff directly discharged into the downstream in the grass planting ditch into an underground pipeline system, and utilize the immobilized microorganisms in the pipeline system, the deep purification is carried out on the rainwater flow, so that the requirements of the land for intercepting, conveying and purifying the rainwater runoff are met under the condition of small land occupation area, meanwhile, the application feasibility of the sponge city system in areas with less land resources and unconditional large runoff storage and purification facilities is enhanced, simultaneously, through combining with traditional municipal administration underground piping drainage system, can form distributed runoff closure, defeated, regulation and storage and purification system in certain area to greatly improve the application flexibility of facility.

The specific technical scheme is as follows:

a flow-guiding immobilized microorganism coupling type grass planting ditch comprises: grass planting ditch body and immobilized microorganism processing unit, the immobilized microorganism processing unit of water conservancy diversion formula includes:

the guide pipe group is arranged in the grass planting ditch body;

the plurality of immobilized microorganism modules are arranged in the guide pipe group and are used for fully immobilizing, converting and degrading various organic and inorganic pollutants in the runoff of rainwater;

the lower ends of the liquid level observation pipes extend into the grass planting ditch body and are communicated with the guide pipe groups, and the liquid level observation pipes are used for periodically detecting the water level condition in the guide pipe groups;

and the drain pipe is communicated with one end of the guide pipe group and used for purifying the rainwater into a municipal rainwater pipeline.

The above-mentioned grass planting ditch of water conservancy diversion formula immobilized microorganism coupling type, wherein, the water conservancy diversion nest of tubes includes: the plurality of guide pipes are arranged in the grass planting ditch body, one ends of the plurality of guide pipes are respectively communicated with the drainage pipe, the immobilized microorganism modules are respectively arranged in the plurality of guide pipes, and the liquid level observation pipes are respectively communicated with the plurality of guide pipes.

The above-mentioned grass planting ditch of water conservancy diversion formula immobilized microorganism coupling type, wherein, each immobilized microorganism module all includes: pipeline inner skleeve and immobilized microorganism, the pipeline inner skleeve is located in the water conservancy diversion pipe, immobilized microorganism locates in the pipeline inner skleeve, the pipeline inner skleeve is the confined cylinder configuration, a plurality of through-holes have been seted up on the surface of pipeline inner skleeve, be equipped with the geotechnological cloth that permeates water in the pipeline inner skleeve.

The grass planting ditch of foretell water conservancy diversion formula immobilized microorganism coupling type, wherein, each the honeycomb duct all includes water conservancy diversion intake end, water conservancy diversion middle section and the water conservancy diversion play water end that connects gradually, the liquid level observation pipe with the water conservancy diversion middle section is linked together, immobilized microorganism module locates in the water conservancy diversion middle section, the water conservancy diversion goes out the water end and keeps away from the one end in water conservancy diversion middle section with the drain pipe is linked together.

Foretell water conservancy diversion formula immobilized microorganisms coupled type's grass planting ditch, wherein, grass planting ditch body includes from supreme drainage blanket, planting soil layer and the stagnant water layer that sets gradually down, the water conservancy diversion is intake the end and is located in the stagnant water layer, the water conservancy diversion middle section the water conservancy diversion goes out the water end with the drain pipe all is located in the planting soil layer, the upper end of liquid level observation pipe is higher than the upper surface of stagnant water layer.

The flow guide type immobilized microorganism coupling type grass planting ditch is characterized in that two overflow weirs are arranged in the stagnant water layer, the lower surfaces of the two overflow weirs are abutted to the upper surface of the planting soil layer, a plurality of flow guide water inlet ends are arranged in the overflow weir, and the bottoms of the flow guide water inlet ends are flush with the bottom of the overflow weir.

The flow guide type immobilized microorganism coupling type grass planting ditch is characterized in that the grass planting ditch is arranged under the ground, the surface layer of the ground is a plain soil foundation, the grass planting ditch comprises a grass planting ditch body and an anti-seepage film, and the anti-seepage film is arranged between the plain soil foundation and the grass planting ditch body.

Foretell water conservancy diversion formula immobilized microorganisms coupled type's grass planting ditch, wherein, be equipped with overflow catch basin in the grass planting ditch, in plain soil foundation was located to overflow catch basin's lower extreme, supreme passing in proper order is followed down followed to overflow catch basin's upper end the drainage blanket with plant the soil layer, and stretch into in the stagnant water layer, overflow catch basin's upper end is equipped with the overflow inlet for stom water, the overflow inlet for stom water with the upper surface of stagnant water layer flushes mutually, the drain pipe with overflow catch basin is linked together.

In the above-mentioned flow guide type immobilized microorganism coupling type grass planting ditch, a perforated water collecting pipe is arranged in the drainage layer, and one end of the perforated water collecting pipe is communicated with the overflow catch basin.

The flow guide type immobilized microorganism coupling type grass planting ditch is characterized in that a permeable geotextile is arranged between the drainage layer and the planting soil layer.

Compared with the prior art, the technical scheme has the positive effects that:

the invention provides a composite grass planting ditch facility for strengthening rainwater storage and purification by coupling immobilized microorganisms with a traditional grass planting ditch and arranging a corresponding flow guide pipe as a carrier. The invention can fully utilize the underground space of the grass planting ditch, guide the surface runoff directly discharged into the downstream in the grass planting ditch into the underground pipeline system, and utilize the immobilized microorganisms in the pipeline system to deeply purify the surface runoff, thereby meeting the requirements of the land on the interception, transportation and purification of the rainwater runoff under the condition of smaller land occupation area, simultaneously enhancing the application feasibility of a sponge city system in areas with less land resources and unconditional large runoff storage and purification facilities, and simultaneously forming a distributed runoff interception, transportation, storage and purification system in a certain area by combining with the traditional municipal underground pipeline drainage system, thereby greatly improving the application flexibility of the facility.

Drawings

FIG. 1 is a plan view of a flow-guiding immobilized microorganism coupled grass-planting trench according to the present invention;

FIG. 2 is a cross-sectional view taken along the direction A-A in FIG. 1 of a flow-guiding immobilized microorganism coupled grass-planting trench according to the present invention;

FIG. 3 is a cross-sectional view taken along the direction B-B in FIG. 1 of a flow-guiding immobilized microorganism coupled type grass-planting trench according to the present invention;

FIG. 4 is a cross-sectional view taken along the direction C-C in FIG. 1 of a flow-guiding immobilized microorganism coupled grass-planting trench according to the present invention;

FIG. 5 is an enlarged view of the flow-guiding immobilized microorganism coupled grass-planting trench of FIG. 1 at D;

FIG. 6 is an enlarged view of the flow-guiding immobilized microorganism coupled grass-planting trench of FIG. 2 at E;

in the drawings: 1. a flow guide pipe group; 2. an immobilized microbial module; 3. a liquid level observation tube; 4. a drain pipe; 5. a flow guide pipe; 6. a pipeline inner sleeve; 7. immobilizing the microorganism; 8. a water diversion and inlet end; 9. guiding the middle section; 10. a diversion water outlet end; 11. a drainage layer; 12. planting a soil layer; 13. a water retention layer; 14. an overflow weir; 15. a plain soil foundation; 16. an impermeable membrane; 17. an overflow catch basin; 18. an upstream weir; 19. a downstream weir; 20. perforating a water collecting pipe; 21. an overflow gully; 22. and (5) water-permeable geotextile.

Detailed Description

The invention is further described with reference to the following drawings and specific examples, which are not intended to be limiting.

FIG. 1 is a plan view of a flow-guiding immobilized microorganism coupled grass-planting trench of the present invention, FIG. 2 is a sectional view taken along the direction A-A in FIG. 1 of the flow-guiding immobilized microorganism coupled grass-planting trench of the present invention, FIG. 3 is a cross-sectional view taken along the direction B-B in FIG. 1 of a flow-guiding immobilized microorganism coupled type grass-planting trench according to the present invention, FIG. 4 is a cross-sectional view taken along the direction C-C in FIG. 1 of a flow-guiding immobilized microorganism coupled type grass-planting trench according to the present invention, FIG. 5 is an enlarged view of the flow-guiding immobilized microorganism coupled type grass-planting trench of FIG. 1 at D, FIG. 6 is an enlarged view of E in FIG. 2 of a flow-guiding immobilized microorganism coupled type grass-planting trench according to the present invention, as shown in fig. 1 to 6, a flow-guiding immobilized microorganism coupled grass planting ditch of a preferred embodiment is shown, comprising: grass planting ditch body and immobilized microorganism processing unit, the immobilized microorganism processing unit of water conservancy diversion formula includes: a water conservancy diversion nest of tubes 1, a plurality of immobilized microorganism module 2, a plurality of liquid level observation pipe 3 and a drain pipe 4, this is internal in the grass planting ditch is located to water conservancy diversion nest of tubes 1, in water conservancy diversion nest of tubes 1 is all located to a plurality of immobilized microorganism module 2, immobilized microorganism module 2 is used for fully fixing, the inside all kinds of organic of runoff of conversion and degradation rainwater, inorganic pollutants, the lower extreme of a plurality of liquid level observation pipe 3 all stretches into the grass planting ditch originally internally, and all be linked together with water conservancy diversion nest of tubes 1, liquid level observation pipe 3 is used for the water level condition in the regular detection water conservancy diversion nest of tubes 1, drain pipe 4 is linked together with water conservancy diversion nest of tubes 1's one end, drain pipe 4 is used for discharging into municipal.

Preferably, liquid level observation pipe 3 is vertical setting, and liquid level observation pipe 3 perpendicular to grass planting ditch surface, the elevation of socle is higher than the normal water level of stagnant water layer 13, and liquid level observation pipe 3 is the PVC material pipeline, and the pipe diameter is 110mm, but not limited to this material and pipe diameter, is connected through three way connection and water conservancy diversion middle section 9, and the socle of honeycomb duct 5 surpasss the normal water level 2cm of stagnant water layer 13.

Preferably, the pipe diameter of the drain pipe 4 is 150mm, but is not limited to the material and the pipe diameter.

Further, as a preferred embodiment, the guide tube group 1 includes: a plurality of honeycomb ducts 5, it is internal that grass planting ditch is all located to a plurality of honeycomb ducts 5, and the one end of a plurality of honeycomb ducts 5 is linked together with drain pipe 4 respectively, and in a plurality of honeycomb ducts 5 were located respectively to a plurality of immobilized microorganism module 2, a plurality of liquid level observation pipes 3 were linked together with a plurality of honeycomb ducts 5 respectively. Preferably, the draft tube 5 is a PVC pipe with a pipe diameter of 110mm, but not limited to this material and pipe diameter, and the downstream ends of the draft tubes 5 are combined by a tee bend and discharged into the overflow gutter inlet through the drain pipe 4.

Further, as a preferred embodiment, each of the immobilized microorganism modules 2 comprises: pipeline inner skleeve 6 and immobilized microorganism 7, pipeline inner skleeve 6 locate in honeycomb duct 5, and immobilized microorganism 7 locates in pipeline inner skleeve 6, and pipeline inner skleeve 6 is confined cylinder configuration, and a plurality of through-holes have been seted up on pipeline inner skleeve 6's surface, are equipped with the geotechnological cloth 22 that permeates water in the pipeline inner skleeve 6. Preferably, the surface of the inner sleeve 6 of the pipeline is uniformly perforated, the opening rate is 50%, and the length of the inner sleeve 6 of the pipeline is 20 cm.

Further, as a preferred embodiment, each flow guiding pipe 5 includes a flow guiding water inlet end 8, a flow guiding middle section 9 and a flow guiding water outlet end 10 connected in sequence, the liquid level observing tube 3 is communicated with the flow guiding middle section 9, the immobilized microorganism module 2 is disposed in the flow guiding middle section 9, and one end of the flow guiding water outlet end 10 far from the flow guiding middle section 9 is communicated with the water discharging pipe 4. Preferably, a plurality of immobilized microorganism modules 2 are arranged in the middle diversion section 9 of each diversion pipe 5, and a plurality of pipeline inner sleeves 6 are connected in series and sealed through rubber rings.

Further, as a preferred embodiment, the immobilized microorganism 7 is prepared by adsorption method, and the adsorption medium is activated carbon, but not limited to this material, and is filled inside the inner sleeve 6 of the pipeline.

The above are merely preferred embodiments of the present invention, and the embodiments and the protection scope of the present invention are not limited thereby.

The present invention also has the following embodiments in addition to the above:

in a further embodiment of the present invention, please refer to fig. 1 to 6, the grass planting ditch body includes a drainage layer 11, a planting soil layer 12 and a stagnant water layer 13 sequentially arranged from bottom to top, the diversion water inlet end 8 is located in the stagnant water layer 13, the diversion middle section 9, the diversion water outlet end 10 and the drainage pipe 4 are all located in the planting soil layer 12, and the upper end of the liquid level observation pipe 3 is higher than the upper surface of the stagnant water layer 13.

Preferably, the water retaining layer 13 is used for receiving rainwater runoff drained from peripheral land parcels, the depth of a normal water level is 20cm, and the height of the water level is controlled to be 10cm through slope relief.

Preferably, the planting soil layer 12 is positioned at the top of the biological water-retaining facility and is filled with nutrient soil, and the component proportion is 10% of coarse sand, 70% of grass carbon and 20% of vermiculite, but the planting soil layer is not limited to the proportion, and the depth is 50 cm.

Preferably, the drainage layer 13 is positioned from the lower part of the planting soil layer 12 to the top of the grass planting furrow plain soil foundation 15, and gravels with the grain diameter of 20 cm-50 cm are filled, and the depth is 20 cm.

In a further embodiment of the present invention, two overflow weirs 14 are disposed in the stagnant water layer 13, the lower surfaces of the two overflow weirs 14 are both pressed against the upper surface of the planting soil layer 12, a plurality of water diversion and inlet ends 8 are disposed in one overflow weir 14, and the bottoms of the water diversion and inlet ends 8 are all flush with the bottom of the one overflow weir 14.

In a further embodiment of the present invention, the grass planting ditch is arranged under the ground, the surface layer of the ground is a plain soil foundation 15, the grass planting ditch comprises a grass planting ditch body and an impermeable membrane 16, and the impermeable membrane 16 is arranged between the plain soil foundation 15 and the grass planting ditch body.

In a further embodiment of the present invention, an overflow catch basin 17 is disposed in the grass planting ditch, the lower end of the overflow catch basin 17 is disposed in the soil foundation 15, the upper end of the overflow catch basin 17 sequentially penetrates through the drainage layer 11 and the planting soil layer 12 from bottom to top and extends into the stagnant water layer 13, the upper end of the overflow catch basin 17 is provided with an overflow catch basin 21, the overflow catch basin 21 is flush with the upper surface of the stagnant water layer 13, and the drain pipe 4 is communicated with the overflow catch basin 17. Preferably, the overflow catch basin 17 is arranged at the outer side of the downstream of the grass planting ditch water storage unit partitioned by the overflow weir 14, the elevation of the wellhead of the overflow catch basin 17 is consistent with the upper surface of the stagnant water layer 13, and a rainwater connecting pipe is arranged in the overflow catch basin 17 and communicated with a municipal rainwater pipeline for controlling the water level in the grass planting ditch and transferring excessive rainwater.

In a further embodiment of the invention, a perforated collector pipe 20 is provided in the drainage layer 11, and one end of the perforated collector pipe 20 is in communication with the overflow catch basin 17. Preferably, the perforated water collecting pipe 20 is laid in the drainage layer 11 along the longitudinal axis of the grass planting ditch, the surface of the perforated water collecting pipe is perforated, the opening rate is 20%, and the perforated water collecting pipe is wrapped by the permeable geotextile 22.

In a further embodiment of the present invention, a water permeable geotextile 22 is provided between the drainage layer 11 and the planting soil layer 12.

In a further embodiment of the invention, the grass planting ditch is a linear pond body, the section of the grass planting ditch is arranged in an inverted trapezoid shape, and the upper ends of two sides of the grass planting ditch are connected with the ground through a plain soil foundation 15. Preferably, two sides of the stagnant water layer 13 of the grass planting ditch body are in direct connection with the natural ground through slope releasing, the slope ratio is 1:3, the rainwater runoff is cut off and transferred, the slope releasing is also kept below the ground surface to keep the structure stable, namely, the seepage-proofing film 16 is laid below the upper surface of the stagnant water layer 13, the slope ratio is 2:1, and the seepage-proofing film 16 is positioned between the grass planting ditch body and the plain soil foundation 15.

In a further embodiment of the present invention, the two weirs 14 comprise: an upstream overflow weir 18 and a downstream overflow weir 19, and the diversion water inlet end 8 is arranged in the upstream overflow weir 18. Preferably, the liquid level observation pipe 3 is positioned behind the upstream overflow weir 18, the overflow catch basin 17 is positioned behind the downstream overflow weir 19, the overflow weirs 14 are arranged at equal intervals along the longitudinal direction of the grass planting ditch, and the ratio of the center distance of the two overflow weirs 14 to the top width of the grass planting ditch is 10: 1.

Preferably, the overflow weir 14 is made of grouted rubbles with a height of 10cm, but is not limited to the above materials, and is arranged in the grass planting ditch at intervals for isolating the treatment unit and retaining part of rainwater runoff in the grass planting ditch.

In a further embodiment of the present invention, the plurality of flow guiding middle sections 9 are all arranged along the longitudinal axis of the grass planting ditch body, the plurality of flow guiding middle sections 9 are respectively symmetrically located at two sides of the perforated water collecting pipe 20, the plurality of flow guiding middle sections 9 located at one side of the perforated water collecting pipe 20 are arranged at equal intervals, and one ends of the plurality of flow guiding water outlet ends 10 far away from the flow guiding middle sections 9 are arranged in parallel. Preferably, the interval between the draft tubes 5 located at both sides of the perforated header pipe 20 is twice the pipe diameter of the draft tube 5, but not limited to this interval, and the height of the center of the draft tube 5 from the top of the planting soil layer 12 is 20 cm.

Preferably, the slope of the draft tube 5 is consistent with the longitudinal slope of the grass planting furrows, but may also be determined from hydraulic calculations.

Preferably, herbaceous plants with drought resistance and water logging resistance are uniformly planted in the grass planting ditches.

The invention discharges the rainwater runoff from the peripheral land to the diversion type immobilized microorganism coupling type grass planting ditch when the system is running, the rainwater runoff in the stagnant water layer 13 of the upstream grass planting ditch is input into the diversion pipe 5 through the diversion water inlet end 8 in the upstream overflow weir 18, is transported in the diversion middle section 9 and the diversion water outlet end 10 at a certain hydraulic gradient, then is discharged into the overflow rainwater well 17 through the drainage pipe 4, finally is transported to the municipal rainwater pipeline, is discharged into the rainwater runoff in the grass planting ditch, is transported to the diversion pipe 5 for short-time regulation and storage after being settled by the upstream grass planting ditch section to remove large garbage and large-particle size suspended particles. In the process, the rainwater runoff sequentially passes through the immobilized microorganism module 2 preinstalled in the guide pipe 5 and fully contacts with the immobilized microorganism 7 therein, various organic and inorganic pollutants in the rainwater runoff are fully fixed, converted and degraded through the metabolism of the microorganisms and the adsorption of the activated carbon particles, and the rainwater runoff purified by the immobilized microorganism module 2 in the guide pipe 5 is discharged into a municipal rainwater pipeline through the drain pipe 4 and the downstream overflow rainwater port 21.

Wherein the rainwater runoff which does not enter the flow guide pipe 5 is conveyed to a downstream municipal pipe network, a natural water body or a water body purification and storage facility through the surface of the grass planting ditch, and part of the rainwater runoff is vertically penetrated to the bottom plain soil foundation 15 through the planting soil layer 12 and the drainage layer 11 in the conveying process, supplements an underground water source, and is collected by a perforated water collecting pipe 20 arranged in the drainage layer 11 and then is discharged into an overflow rainwater port 21.

The invention can regularly detect the water level condition in the draft tube 5 by arranging the liquid level observation tube 3, and can combine greening maintenance under the condition of long-time drought and serious water loss in the draft tube 5, and input artificial water from the grass planting ditch in the liquid level observation tube 3 or the upstream by an artificial water replenishing mode to meet the growth requirement of the immobilized microorganism 7 in the draft tube 5.

The invention relates to a flow guide type immobilized microorganism coupled grass planting ditch, which is characterized in that a flow guide system containing prefabricated immobilized microorganisms 7 is arranged in the underground part of the traditional grass planting ditch along the hydraulic gradient direction by fully utilizing the underground space of the grass planting ditch and the linear configuration with high length-width ratio, the original water body directly discharged into a downstream drainage pipe network or the surface of the grass planting ditch of the water body in an overflow mode is intercepted and transferred into an underground pipeline system for temporary regulation and storage, and various pollutants in the water body are fully fixed and degraded by utilizing an immobilized microorganism module 2 coupled in the pipeline system through the adsorption and metabolism actions in the regulation and storage and transfer processes, and finally, the rainwater runoff quality is purified and then discharged into the downstream pipe network or the water body.

On the basis of the rainwater runoff conveying function of the traditional grass planting ditch, the rainwater storage and purification capacity is enhanced, the composite function of the facility is enhanced, and the requirements of peripheral plots on rainwater conveying, storage regulation and pollution load reduction functions are met under the condition of smaller comprehensive land use area. The method has strong application value in the region with extremely tight land resources.

While the invention has been described with reference to a preferred embodiment, it will be understood by those skilled in the art that various changes in form and detail may be made therein without departing from the spirit and scope of the invention.