Multifunctional ecological unit riparian zone structure for reducing runoff pollution

Abstract

The utility model discloses a multifunctional ecological unit riparian zone structure for reducing runoff pollution. The multifunctional ecological unit riparian zone structure comprises a green land unit arranged on a high land on the bank side, a gabion unit arranged on a side slope and a water side wetland unit arranged beside a river water body. The greenbelt unit comprises a soil layer, and an ecological plant layer is arranged on the surface of the soil layer; the gabion unit comprises four gabion units, the bottom of the first gabion unit and the bottom of the second gabion unit are located at the same height, and the contact portions of the first gabion unit and the second gabion unit form a viscous flow zone. A 10% first slope is arranged at the top of the second gabion unit, and a controllable water outlet is formed in the bottom of the second gabion unit; and the waterside wetland unit comprises wetland soil and emergent aquatic plants planted in the wetland soil. By optimizing the water flow path and organically combining the multifunctional ecological units, pollutants in rainwater runoff can be efficiently reduced, meanwhile, the ecological function of a riparian zone is recovered, and the water quality purification capacity, the landscape function and the ecological system service capacity of the riparian zone are improved.

Description

TECHNICAL FIELD

[0001] The utility model relates to the field of environmental engineering technology especially relates to a multifunctional ecological unit river bank zone structure of runoff pollution reduction. TECHNICAL BACKGROUND

[0002] River bank zone generally refers to the two sides of the junction of river water and land, and the zone until the influence of river water disappears, due to its special location, here becomes the terrestrial habitat that is strongly influenced by aquatic environment, therefore it has unique spatial structure and ecological function, research shows that river bank zone coordinates the material and energy flow of river transverse and longitudinal through filtering and intercepting sediments, water and nutrients etc., and thus plays an important role in reducing the degree of soil erosion, channel stabilization, biological habitat protection and water quality improvement related thereto.

[0003] With the acceleration of urbanization process, the hardening area of city surface increases significantly, the natural ecological function of river bank zone is continuously eroded, the amount and flow rate of rainwater runoff rapidly increase, which aggravates the urban flood risk and water pollution problem, rainwater runoff carries a large amount of pollutants, including suspended particulate matter, heavy metals, organic pollutants and nitrogen and phosphorus nutrients, these pollutants will cause serious negative effects on water quality and ecological system after entering rivers, lakes and other water bodies.

[0004] At present, the existing urban drainage system takes rapid drainage as the core target, through the construction of pipelines, ditches and other facilities, rainwater runoff is rapidly guided out of the urban area to reduce the risk of waterlogging. However, this drainage method ignores the treatment of pollutants in runoff and fails to fully exert the interception and purification capacity of natural ecological system on pollutants. In recent years, with the improvement of ecological environmental protection consciousness, measures such as sunken green land, permeable pavement, rainwater garden and green roof are also constructed to realize the on-site collection, storage and purification of rainwater, so as to reduce runoff and the pollutants carried thereby. However, these methods still have the following technical and management challenges in practical application:

[0005] (1) The existing ecological facilities may not have sufficient runoff pollutant reduction capacity in the face of high intensity rainfall or high pollutant load, resulting in part of the pollutants flowing into downstream water bodies;

[0006] (2) Most ecological facilities need regular maintenance, such as vegetation management, filler replacement, etc., which has high operation cost and increases the difficulty of implementation;

[0007] (3) Some designs have high requirements for terrain, site area and environmental conditions, which are difficult to be widely applied in dense urban areas. CONTENT OF THE UTILITY MODEL

[0008] The utility model discloses a multifunctional ecological unit river bank zone structure of cutting down runoff pollution, through the organic combination of optimizing water flow path design and multifunctional ecological unit, the efficient cutting down of the pollutant in rainwater runoff is realized, and the ecological function of the river bank zone is recovered, and its water quality purification capacity, landscape function and ecological system service capacity are improved.

[0009] In order to realize the above-mentioned goal, the utility model adopts the following technical scheme:

[0010] The river bank zone structure includes a green land unit arranged on a river bank highland, a stone cage unit arranged on a side slope and a water edge wetland unit arranged beside a river water body.

[0011] 1. The green land unit

[0012] The green land unit is arranged on the upstream of the river bank purification system, is used for preliminarily intercepting and absorbing the suspended particulate matters and part of the dissolved pollutants in the runoff, and the main components of the green land unit are a soil layer and an ecological plant layer planted on the surface of the soil layer.

[0013] The ecological plant layer: selects the herbaceous plant or shrub with strong adaptability and pollution resistance, the root system of which effectively intercepts the suspended particles and dissolved pollutants in the runoff through adsorption and fixation, and decomposes part of the organic pollutants through the natural process of plant growth, and simultaneously improves the ecological function of the green land.

[0014] The soil layer: provides the necessary growth substrate for the plant, and further filters the large particulate matters and part of the pollutants in the runoff, reduces the treatment load of the subsequent treatment unit, and improves the overall efficiency of the system.

[0015] 2. The stone cage unit

[0016] The stone cage unit includes four stone cage subunits, the first stone cage subunit, the second stone cage subunit, the third stone cage subunit and the fourth stone cage subunit are arranged on the side slope in a ladder type from top to bottom, different functional fillers are filled in each stone cage subunit, the first stone cage subunit and the second stone cage subunit are arranged closely and the bottoms are located at the same height, the contact part forms a stagnant flow zone, the bottom of the first stone cage subunit and the second stone cage subunit is consistent with the top of the third stone cage subunit, the bottom of the third stone cage subunit is consistent with the top of the fourth stone cage subunit, the top of the second stone cage subunit is provided with a first slope with a slope of 10%, and the bottom is provided with a controllable drainage port, the drainage frequency and the drainage amount can be controlled through the controllable drainage port, and emergent aquatic plants are planted on the top of each stone cage subunit.

[0017] The stone cage unit is the core part of the river bank purification system, and the design combines the stepped structure and the stagnant zone, which significantly improves the residence time of the water body in the treatment unit and the removal efficiency of the pollutants. The stagnant zone is arranged between the first stone cage sub-unit and the second stone cage sub-unit, the residence time of the water body is prolonged by optimizing the water flow path, and the treatment effect of the pollutants is improved. The water flow path is as follows: the water flow flows into the bottom outlet from the top of the first stone cage sub-unit, intercepts larger particles, enters the bottom of the second stone cage sub-unit, flows upward from the bottom, and overflows into the third stone cage sub-unit through the first slope with a slope of 10% at the top, and then flows to the fourth stone cage sub-unit, so that the adsorption and filtration capacity of the filler is fully utilized. The bottom of the second stone cage sub-unit is provided with a controllable drainage port, and the drainage frequency and water volume can be adjusted according to actual needs, so that anaerobic fermentation or odor of the water body in the stagnant zone due to long residence time is prevented, and the long-term operation stability of the system is ensured.

[0018] 3. Water edge wetland unit

[0019] The water edge wetland unit is arranged at the end of the river bank purification system, and includes wetland soil and emergent plants planted in the wetland soil.

[0020] The main function of the water edge wetland unit is to deeply purify the runoff treated by the green land unit and the stone cage unit, and further remove residual pollutants. The emergent plants such as reed and cattail are selected, the developed root system of which can adsorb the residual pollutants in the water body and provide attachment points for the microbial community. The wetland soil layer acts as a filter medium, and at the same time, the organic pollutants are decomposed by the metabolic activity of the microorganisms, so that the water quality is further purified, and the pollutant emission is reduced.

[0021] Preferably, the filler of the first stone cage sub-unit adopts 50-100mm pebbles, which is mainly used for intercepting large particle suspended matters in the runoff, the filler of the second stone cage sub-unit adopts 10-20mm pebbles and ceramsite, the porous structure of the ceramsite provides a larger adsorption area, which can effectively adsorb dissolved organic matter, the filler of the third stone cage sub-unit adopts 5-8mm pebbles and medical stone, which further adsorbs pollutants, and the filler of the fourth stone cage sub-unit adopts 3-4mm pebbles and biomass charcoal, which removes refractory organic matter, so that deep purification is realized.

[0022] Preferably, a second slope with a slope of 30% is arranged at the joint of the green land unit and the stone cage unit.

[0023] Preferably, each stone cage sub-unit is wrapped with galvanized low-carbon steel wire mesh, and the bottom is paved with geotextile.

[0024] Preferably, an overflow weir is arranged at the end of the first slope at the top of the second stone cage sub-unit.

[0025] Compared with the disadvantages and deficiencies of the prior art, the utility model has the following beneficial effects:

[0026] (1) The utility model discloses on the basis of traditional ladder type gabion unit increases the design of the lag flow zone, significantly prolongs the water body residence time, optimizes the pollutant settlement, adsorption and decomposition process, realizes the efficient treatment of city runoff water, and significantly enhances the ecosystem service function of the river bank zone.

[0027] (2) The utility model discloses the bottom of the second gabion subunit is provided with a controllable drainage port, and the controllable drainage port can control the drainage frequency and water volume according to actual needs, prevents the lag flow zone water body from producing anaerobic fermentation or peculiar smell due to long-time residence, and ensures the long-term operation stability of the system.

[0028] (3) The utility model improves the pollutant reduction efficiency, effectively increases the urban greening area, promotes the biological diversity, improves the river bank landscape, and improves the urban ecological environment quality.

[0029] (4) The utility model discloses that the gabion unit adopts modular design, combines functional fillers such as pebbles, ceramsite, rhyolite and biomass charcoal, and the top planting emergent plants, effectively enhances the pollutant reduction effect, ensures the system operation stability, is simple in operation and maintenance, is high in economic feasibility, ensures the long-term stable operation of the system, and reduces the management and maintenance cost. BRIEF DESCRIPTION OF DRAWINGS

[0030] Figure 1 It is the river bank structure schematic diagram of the multifunctional ecological unit of the utility model embodiment.

[0031] The figure mark is: 1, green land unit;1-1, ecological plant layer;1-2 soil layer;2, gabion unit;2-1, first gabion subunit;2-2, second gabion subunit;2-3 third gabion subunit;2-4, fourth gabion subunit;2-5, lag flow zone;2-6, first slope;2-7, controllable drainage port;2-8, overflow weir;2-9, pebble aggregate;2-10, pebble and ceramsite;2-11, pebble and rhyolite;2-12, pebble and biomass charcoal;3, water edge wetland unit;4, second slope;5, emergent plant. DETAILED DESCRIPTION

[0032] The technical scheme of the utility model will be described clearly and completely in combination with the drawings in the utility model embodiments. Obviously, the described embodiments are only part of the embodiments of the utility model, not all the embodiments. Based on the embodiments in the utility model, all other embodiments obtained by those skilled in the art without creative labor belong to the protection scope of the utility model.

[0033] As Figure 1As shown, the utility model discloses green land unit 1, gabion unit 2, water edge wetland unit 3. Green land unit 1 sets up in the starting part of river bank zone purification system, mainly by ecological vegetation 1-1 and soil layer 1-2 constitutes, is used for preliminary interception and absorption runoff pollutant, and the junction of green land unit 1 and gabion unit 2 is equipped with the second slope 4 of 30% gradient.

[0034] Gabion unit 2 adopts ladder type structure, and is divided into four gabion subunits from left to right, the bottom of first gabion subunit 2-1 and second gabion subunit 2-2 is located at the same height, and forms stagnant flow zone 2-5 in the middle, and is consistent with the top height of third gabion subunit 2-3, and the bottom of third gabion subunit 2-3 is consistent with the top height of fourth gabion subunit 2-4, and the top of second gabion subunit 2-2 is equipped with the first slope 2-6 of 10% gradient, and is equipped with flow controllable drainage outlet 2-7 at the bottom, and controllable drainage outlet 2-7 can control drainage frequency and drainage capacity, and the end of first slope 2-6 of second gabion subunit 2-2 top is designed overflow weir 2-8.

[0035] First gabion subunit 2-1 filler adopts 50~100mm's pebble aggregate 2-9, mainly for intercepting the large particle suspended matter in runoff, second gabion subunit 2-2 filler adopts 10~20mm's pebble and ceramsite 2-10, and the porous structure of ceramsite provides greater adsorption area, can effectively adsorb dissolved organic matter, third gabion subunit 2-3 filler adopts 5~8mm's pebble and medical stone 2-11, further adsorbs pollutant, fourth gabion subunit 2-4 filler adopts 3~4mm's pebble and biomass charcoal 2-12, removes refractory organic matter, realizes depth purification.

[0036] Each gabion subunit is wrapped by galvanized steel wire mesh, and the edge and gap are fixed by wire binding, so as to keep the stability of the whole device, and the top is planted with strong emergent plant 5, which provides additional ecological benefits for runoff purification.

[0037] Water edge wetland unit 3 is located at the end of river bank zone purification system, and is composed of emergent plant 5 and wetland soil 3-1, and through the synergistic effect of plant root system, soil and microorganism, water is deeply purified.

[0038] The utility model rainwater treatment process is explained as follows:

[0039] Firstly, the ecological vegetation layer 1-1 of the green space unit 1 adsorbs and fixes the pollutants in the runoff through its root system, while enhancing the ecological function of the green space; the soil layer 1-2 further filters the large particle substances in the runoff and provides growth substrate for the vegetation, enhancing the long-term stability of the system. The green space unit 1 also slows down the flow speed of the water, reducing the load on the subsequent treatment units. The rainwater that has been preliminarily purified flows into the stone cage unit 2, which is composed of multiple stone cage sub-units arranged in a stepped manner. The rainwater flows into the first stone cage sub-unit 2-1 filled with pebble aggregate 2-9, intercepting larger suspended particles. The rainwater enters the bottom of the second stone cage sub-unit 2-2 through the stagnant zone 2-5 and flows upward from the bottom. The second stone cage sub-unit 2-2 is filled with pebbles and ceramsite 2-10, which adsorb organic pollutants. From the top of the second slope 2-6 of the second stone cage sub-unit 2-2, the rainwater flows into the third stone cage sub-unit 2-3 filled with pebbles and medical stone 2-11, further adsorbing pollutants in the water. The rainwater then flows into the fourth stone cage sub-unit 2-4 filled with pebbles and biochar 2-12, removing difficult-to-degrade organic matter and achieving deep purification. At the same time, emergent plants 5 such as irises and cattails are planted on the top of the stone cage unit, and the plant roots further adsorb pollutants and work synergistically with microorganisms to decompose organic matter. Finally, the rainwater passes through the stone cage unit 2 and enters the riparian wetland unit 3, where the emergent plants 5, wetland soil 3-1, and microorganisms work synergistically to further purify the residual pollutants in the runoff. The emergent plants 5 fix pollutants through their extensive root systems and provide attachment points for rhizosphere microorganisms. The wetland soil 3-1 layer acts as a filter medium and further degrades organic pollutants through microbial metabolic activity, ultimately outputting cleaner water that flows into the river.

[0040] During use, to ensure long-term stable operation and high-efficiency purification effect of the system, regular inspection and maintenance of the structure and function of each unit are required. The green space unit 1 needs to be regularly pruned to prevent excessive growth from affecting the filtration effect; the stone cage unit 2 needs to monitor the adsorption capacity of the filler and replace materials such as ceramsite, medical stone, or biochar according to usage, while maintaining the stability of the overall structure of the stone cage; the riparian wetland unit 3 needs to monitor the coverage and growth of wetland plants and, if necessary, replant or replace part of the soil to ensure the balance of the wetland ecosystem. In addition, regular monitoring of the water quality entering and exiting the system is required, including changes in the concentrations of suspended particles, dissolved organic matter, heavy metals, and nitrogen and phosphorus nutrients, to evaluate the purification effect of the system and adjust the operating parameters in a timely manner.

[0041] The utility model discloses a green land unit 1, gabion unit 2 and the organic combination of water edge wetland unit 3 has constructed the efficient runoff pollution reduction system, can remove various pollutants in rainwater runoff, and through the synergies of plant and microorganism, the service function of river bank zone ecosystem is significantly promoted.

[0042] The above merely describes the preferred embodiments of the utility model and is not intended to limit the utility model, and any modification, equivalent replacement and improvement made within the spirit and principle of the utility model should be included in the protection scope of the utility model.

Claims

1. A multifunctional ecological unit riparian zone structure for reducing runoff pollution, characterized in that, The application relates to a riverbank ecological restoration structure, which comprises a green land unit arranged on a riverbank highland, a stone cage unit arranged on a slope and a water edge wetland unit arranged beside a river water body; the green land unit comprises a soil layer, and an ecological plant layer is arranged on the surface of the soil layer; the stone cage unit comprises four stone cage subunits, i.e. a first stone cage subunit, a second stone cage subunit, a third stone cage subunit and a fourth stone cage subunit, which are arranged on the slope in a ladder type from top to bottom; different functional fillers are filled in each stone cage subunit; the first stone cage subunit and the second stone cage subunit are arranged closely and the bottoms are located at the same height, the contact part forms a flow retardation zone, the bottom of the first stone cage subunit and the second stone cage subunit is consistent with the top of the third stone cage subunit, the bottom of the third stone cage subunit is consistent with the top of the fourth stone cage subunit; a first slope with a slope of 10% is arranged on the top of the second stone cage subunit, a controllable drainage port is arranged at the bottom, and the drainage frequency and the drainage amount can be controlled through the controllable drainage port; emergent plants are planted on the top of each stone cage subunit; the water edge wetland unit comprises wetland soil and emergent plants planted in the wetland soil.

2. The multifunctional ecotope riparian zone structure according to claim 1, characterised by the fact that, The filler of the first stone cage subunit is 50-100mm pebble aggregate, the filler of the second stone cage subunit is 10-20mm pebble and ceramsite, the filler of the third stone cage subunit is 5-8mm pebble and medical stone, and the filler of the fourth stone cage subunit is 3-4mm pebble and biomass charcoal.

3. The multifunctional ecotope riparian zone structure according to claim 1, characterised by that, A second slope with a slope of 30% is arranged at the joint of the green land unit and the stone cage unit.

4. The multifunctional ecotope riparian zone structure according to claim 1, characterised by that, Each stone cage subunit is wrapped with a galvanized low-carbon steel wire mesh, and geotextile is laid at the bottom.

5. The multifunctional ecotope riparian zone structure according to claim 1, characterised in that, An overflow weir is designed at the end of the first slope on the top of the second stone cage subunit.

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