Riparian zone ecological buffering and intercepting system and method for preventing diffusion of non-point source pollution

Abstract

The invention discloses a riparian zone ecological buffer interception system and method for preventing diffusion of non-point source pollution, and the system comprises the following components which are sequentially arranged along the slope direction of a riparian zone: a substrate layer which is formed by mixing straw fiber, zeolite and humus soil according to the mass ratio of 2: 1: 3, has the thickness of 30-50cm and is laid on the surface layer of the riparian zone. When the scheme is implemented, through the multi-layer design of the substrate layer, the vegetation layer, the flow guide structure and the permeable dam body, suspended solids, nitrogen and phosphorus nutritive salt and heavy metal are intercepted and adsorbed in a graded mode; based on dynamic feedback of the pollution load monitoring module, the flow guide structure and the permeable dam can automatically adjust the angle or porosity to adapt to different flow and pollutant concentration scenes, and overload of the system is avoided; local stain-resistant plants (such as reeds and cattails) are selected for the vegetation layer, and in combination with microflora of the substrate layer, pollution degradation and biodiversity improvement of the riparian zone are synchronously achieved.

Description

Technical Field

[0001] This application relates to the field of ecological restoration technologies, and particularly to a riparian ecological buffer interception system and method for preventing the spread of non-point source pollution. Background Art

[0002] Non-point source pollution is one of the main sources of water pollution. Its characteristics are that the pollution sources are dispersed and the migration paths are complex. Especially during rainfall or farmland drainage, pollutants enter rivers through surface runoff, leading to water eutrophication and ecosystem degradation. Traditional riparian pollution control methods mainly include physical interception (such as concrete revetments and sewage interception ditches) and plant buffer zones.

[0003] However, the existing technologies have significant defects: 1. Although physical interception facilities (such as hard revetments) can intercept sewage in the short term, they damage the ecological functions of the riverbank and cannot degrade pollutants; 2. A single plant buffer zone relies on the adsorption effect of vegetation, and its interception efficiency drops sharply under heavy rain or high pollution loads, and it lacks the ability to actively regulate the migration paths of pollutants. Summary of the Invention

[0004] Therefore, this application provides a riparian ecological buffer interception system and method for preventing the spread of non-point source pollution to solve the problems of the existing technologies, such as the inability to degrade pollutants and the lack of the ability to actively regulate the migration paths of pollutants.

[0005] To achieve the above object, this application provides the following technical solutions:

[0006] In a first aspect, a riparian ecological buffer interception system for preventing the spread of non-point source pollution includes the following components arranged in sequence along the slope direction of the riparian zone:

[0007] A substrate layer, which is composed of straw fiber, zeolite, and humus soil mixed in a mass ratio of 2:1:3. The thickness of the substrate layer is 30 - 50 cm, and it is laid on the surface layer of the riparian zone for adsorbing suspended solids and dissolved pollutants in the runoff.

[0008] A vegetation layer, which is planted above the substrate layer and is composed of pollution-tolerant herbaceous plants and shrubs distributed in a staggered strip pattern. The depth of the plant roots is not less than 1.5 times the thickness of the substrate layer.

[0009] A diversion structure, which is arranged on the downstream side of the vegetation layer and includes an adjustable-angle diversion plate and a bottom water collection trough. The surface of the diversion plate is covered with a biofilm carrier material.

[0010] A permeable dam body, which is located downstream of the diversion structure and is formed by stacking gravel and ecological concrete blocks. It is internally provided with multiple vertical flow filtration channels, and the channels are filled with pyrite-limestone composite fillers.

[0011] The monitoring module includes a flow sensor installed at the entrance of the diversion structure, a water quality monitoring probe in the substrate layer, and a turbidity sensor at the outlet of the permeable dam body;

[0012] The grit chamber is located downstream of the permeable dam body. The bottom of the chamber is sloped and is equipped with a sand discharge pipe. Submerged plants are planted in the chamber;

[0013] The flexible enclosure is installed at the junction of the grit chamber and the river. It is composed of a combination of a high-density polyethylene net and an ecological floating bed. Emergent plants are planted on the floating bed.

[0014] Preferably, the angle between the diversion plate of the diversion structure and the ground can be electrically adjusted within the range of 15° - 60°. The surface of the diversion plate is provided with a honeycomb-shaped polyethylene carrier layer, and the carrier layer is inoculated with a composite bacterium agent of denitrifying bacteria and polyphosphate-accumulating bacteria.

[0015] Preferably, the pyrite-limestone composite filler filled in the vertical flow filtration channel of the permeable dam body has a particle size of 5 - 20 mm, the mass ratio of pyrite to limestone is 1:2 - 1:4, and the total height of the filler layer accounts for 2 / 3 of the height of the permeable dam body.

[0016] Preferably, the monitoring module is communicatively connected to the central controller. The central controller dynamically adjusts the angle of the diversion plate and the internal water flow distribution ratio of the permeable dam body according to the real-time monitored flow rate and pollutant concentration data.

[0017] Preferably, the outlet of the sand discharge pipe of the grit chamber is connected to a sludge drying bed. A sand filtration layer and an earthworm decomposition area are laid in the drying bed, and the dried sediment is backfilled into the substrate layer.

[0018] Preferably, the ecological floating bed of the flexible enclosure is spliced into a grid-shaped frame by modified PVC pipes. The frame is filled with coconut coir fiber matrix, and the planting density of emergent plants is 20 - 30 plants / m 2 .

[0019] Preferably, an anti-seepage isolation layer is further provided below the substrate layer, which is composed of a composite of bentonite and geotextile, with a thickness of 10 - 15 cm and an anti-seepage coefficient ≤ 1×10 -7 cm / s.

[0020] In a second aspect, a method for ecological buffer interception of a riparian zone to prevent the spread of non-point source pollution includes the following steps:

[0021] The first step, topographic survey and system design: According to the slope of the riparian zone, the surface runoff path, and historical pollution data, determine the laying range of the substrate layer, the installation position of the diversion structure, and the height of the permeable dam body;

[0022] The second step, construction of the substrate layer and the vegetation layer: Mix straw fiber, zeolite, and humus soil according to the ratio to form the substrate layer. After compaction, plant pollution-tolerant plants, and initially use a drip irrigation system to maintain soil moisture;

[0023] Step 3, Debugging of the diversion structure and the permeable dam body: Set the initial angle of the deflector to 30°, and pre-fill the vertical flow channel of the permeable dam body with water to activate the microbial community.

[0024] Step 4, System operation and dynamic regulation: Obtain data on flow rate, turbidity, and nitrogen and phosphorus concentrations through the monitoring module. When the pollutant load exceeds the threshold, the central controller increases the angle of the deflector to 45° - 60°, and increases the water flow distribution in the western channel of the permeable dam body.

[0025] Step 5, Maintenance and management: Clean the sediment in the grit chamber every quarter and backfill it into the drying bed, and prune the vegetation layer and replenish the humus soil in the substrate layer every winter.

[0026] Preferably, the specific logic of the dynamic regulation described in Step 4 is as follows:

[0027] When the flow sensor detects that the runoff increases by more than 50% and lasts for 10 minutes, the angle of the deflector is increased to 50°.

[0028] When the water quality monitoring probe detects that the ammonium nitrogen concentration exceeds 2 mg / L, the eastern channel of the permeable dam body is closed, forcing the water to flow through the western high-pyrite proportion packing area.

[0029] When the value of the turbidity sensor exceeds 50 NTU, the sand discharge pipe of the grit chamber is automatically opened.

[0030] Compared with the prior art, the present application has at least the following beneficial effects:

[0031] 1. Through the multi-layer design of "substrate layer - vegetation layer - diversion structure - permeable dam body", hierarchical interception and adsorption of suspended solids, nitrogen and phosphorus nutrients, and heavy metals are achieved.

[0032] 2. Based on the dynamic feedback of the pollution load monitoring module, the diversion structure and the permeable dam can automatically adjust the angle or porosity to adapt to different flow rates and pollutant concentration scenarios, avoiding system overload.

[0033] 3. The vegetation layer selects local pollution-tolerant plants (such as reeds and cattails), combined with the microbial community in the substrate layer, to simultaneously achieve pollution degradation and improvement of riparian biodiversity. Description of the Drawings

[0034] To more intuitively illustrate the prior art and the present application, exemplary drawings are given below. It should be understood that the specific shapes and structures shown in the drawings generally should not be regarded as limiting conditions when implementing the present application; for example, those skilled in the art are capable of making routine adjustments or further optimizations to the addition / deletion / attribution division of certain units (components), specific shapes, positional relationships, connection methods, dimensional proportional relationships, etc. based on the technical concept disclosed in the present application and the exemplary drawings.

[0035] Figure 1 Structural schematic diagram of a riparian ecological buffer interception system for preventing non-point source pollution diffusion provided by this application;

[0036] Figure 2 Schematic diagram of the monitoring module of a riparian ecological buffer interception system for preventing non-point source pollution diffusion provided by this application.

[0037] In the figure: 101, matrix layer; 102, vegetation layer; 103, diversion structure; 104, permeable dam body; 105, monitoring module; 106, grit chamber; 107, flexible enclosure;

[0038] 1031, diversion plate; 1032, bottom water collecting trough;

[0039] 1051, flow sensor; 1052, water quality monitoring probe; 1053, turbidity sensor;

[0040] 1061, sand discharge pipe. Specific implementation manners

[0041] The following further details this application through specific embodiments in conjunction with the accompanying drawings.

[0042] As Figure 1-2 shown, a riparian ecological buffer interception system for preventing non-point source pollution diffusion includes the following components arranged in sequence along the slope direction of the riparian zone:

[0043] Matrix layer 101, which is composed of straw fiber, zeolite and humus soil mixed in a mass ratio of 2:1:3. The thickness of the matrix layer 101 is 30 - 50 cm, and it is laid on the surface layer of the riparian zone, used to adsorb suspended solids and dissolved pollutants in the runoff. As the first barrier for pollution interception, it adsorbs suspended solids and dissolved pollutants in the runoff, where the straw fiber provides a porous structure to intercept particulate matter; the zeolite adsorbs ammonium nitrogen through ion exchange; the humus soil enhances the microbial activity to degrade organic matter;

[0044] Vegetation layer 102 is planted above the matrix layer 101 and is composed of pollution-tolerant herbaceous plants and shrubs distributed in a zonal staggered manner. The depth of the plant roots is not less than 1.5 times the thickness of the matrix layer. The vegetation layer 102 further purifies the water body through the physical interception and biochemical effects of the plant roots and stems and leaves, and deep-rooted plants (such as reeds) can stabilize the soil and absorb dissolved pollutants; shrubs (such as willows) can slow down the surface runoff speed;

[0045] The diversion structure 103 is provided on the downstream side of the vegetation layer 102, and includes an adjustable-angle diversion plate 1031 and a bottom water collection tank 1032. The surface of the diversion plate 1031 is covered with a biofilm carrier material. The diversion structure 103 can dynamically regulate the water flow path, enhance the ability to intercept pollutants and microbial degradation. The adjustable diversion plate 1031 can adjust the angle according to the flow rate to optimize the water flow distribution; the water collection tank 1032 collects the water body after diversion; the biofilm carrier on the surface of the diversion plate 1031 enriches denitrifying bacteria and phosphorus-accumulating bacteria;

[0046] The permeable dam body 104 is used for deep purification of water body, intercepting residual pollutants and regulating water flow. It is located downstream of the diversion structure 103 and is formed by stacking gravel and ecological concrete blocks. It is internally provided with multi-stage vertical flow filtration channels, and the channels are filled with pyrite-limestone composite fillers;

[0047] The monitoring module 105 is used to monitor the pollution load in real time and feedback control signals, including a flow sensor 1051 provided at the entrance of the diversion structure 103, a water quality monitoring probe 1052 in the substrate layer 101, and a turbidity sensor 1053 at the outlet of the permeable dam body 104. The flow sensor 1051 is used to warn of sudden changes in runoff; the water quality probe 1052 is used to detect the pollutant concentration; the turbidity sensor 1053 is used to evaluate the purification effect;

[0048] The grit chamber 106 is used to precipitate suspended particles and recover sediments. It is located downstream of the permeable dam body 104. The bottom of the chamber is sloped and is provided with a sand discharge pipe 1061. Submerged plants are planted in the chamber, and the sloped bottom of the chamber is used to promote the settlement of sand particles;

[0049] The flexible enclosure 107 is used to intercept floating objects at the end and beautify the riverbank landscape. It is provided at the junction of the grit chamber 106 and the river channel and is composed of a high-density polyethylene net and an ecological floating bed. Emergent plants are planted on the floating bed.

[0050] The included angle between the diversion plate 1031 of the diversion structure 103 and the ground can be electrically adjusted within the range of 15° - 60°. The surface of the diversion plate is provided with a honeycomb-shaped polyethylene carrier layer, and the carrier layer is inoculated with a composite bacterium agent of denitrifying bacteria and phosphorus-accumulating bacteria.

[0051] The pyrite-limestone composite filler filled in the vertical flow filtration channel of the permeable dam body 104 has a particle size of 5 - 20 mm, the mass ratio of pyrite to limestone is 1:2 - 1:4, and the total height of the filler layer accounts for 2 / 3 of the height of the permeable dam body. The pyrite-limestone composite filler removes pollutants through the synergy of chemical precipitation (limestone neutralizes acidity) and redox (pyrite decomposes organic matter).

[0052] The monitoring module 105 is communicatively connected to the central controller. The central controller dynamically adjusts the angle of the diversion plate and the internal water flow distribution ratio of the permeable dam body according to the real-time monitored flow rate and pollutant concentration data.

[0053] The outlet of the sand discharge pipe 1061 of the grit chamber 106 is connected to a sludge drying bed. A sand filter layer and an earthworm decomposition area are laid in the drying bed, and the dried sediment is backfilled into the substrate layer. Connecting the sand discharge pipe 1061 to the drying bed realizes the resource utilization of sludge recycling; submerged plants are used to absorb residual nutrients.

[0054] The ecological floating bed of the flexible enclosure 107 is composed of modified PVC pipes spliced into a grid-shaped frame. The frame is filled with coconut shell fiber matrix, and the planting density of emergent plants is 20 - 30 plants / m 2 。

[0055] An anti-seepage isolation layer is also provided below the substrate layer 101, which is composed of a composite of bentonite and geotextile, with a thickness of 10 - 15 cm and a seepage coefficient ≤ 1×10 -7 cm / s.

[0056] An ecological buffer interception method for riverbank zones to prevent the spread of non-point source pollution includes the following steps:

[0057] The first step, topographic survey and system design: According to the slope of the riverbank zone, the surface runoff path, and historical pollution data, determine the laying range of the substrate layer, the installation position of the diversion structure, and the height of the permeable dam body;

[0058] The second step, construction of the substrate layer and vegetation layer: Mix straw fiber, zeolite, and humus soil according to the ratio to form the substrate layer. After compaction, plant pollution-tolerant plants, and use a drip irrigation system to maintain soil moisture in the initial stage;

[0059] The third step, commissioning of the diversion structure and permeable dam body: Set the initial angle of the guide plate to 30°, and pre-fill water in the vertical flow channel of the permeable dam body to activate the microbial community;

[0060] The fourth step, system operation and dynamic regulation: Obtain data on flow rate, turbidity, and nitrogen and phosphorus concentrations through the monitoring module. When the pollutant load exceeds the threshold, the central controller increases the angle of the guide plate to 45° - 60°, and increases the water flow distribution in the western channel of the permeable dam body;

[0061] The fifth step, maintenance and management: Clean the sediment in the grit chamber and backfill it into the drying bed every quarter, and prune the vegetation layer and supplement the humus soil in the substrate layer every winter

[0062] The specific logic of the dynamic regulation described in the fourth step is as follows:

[0063] When the flow sensor detects that the runoff increases by more than 50% and lasts for 10 minutes, the angle of the guide plate is increased to 50°;

[0064] When the water quality monitoring probe detects that the ammonium nitrogen concentration exceeds 2 mg / L, the eastern channel of the permeable dam body is closed, forcing the water to flow through the western high-pyrite proportion filler area;

[0065] When the value of the turbidity sensor exceeds 50 NTU, the automatic opening of the sand discharge pipe of the grit chamber is triggered.

[0066] The technical features of the above embodiments can be combined arbitrarily (as long as there is no contradiction in the combination of these technical features). For the sake of concise description, not all possible combinations of the technical features in the above embodiments are described; these embodiments not explicitly written out should also be considered to be within the scope described in this specification.

Claims

1. An ecological buffer interception system for riverbanks to prevent the spread of non-point source pollution, characterized in that, It includes the following components arranged successively along the slope direction of the riparian zone: The substrate layer (101) is composed of straw fiber, zeolite and humus soil mixed in a mass ratio of 2:1:

3. The thickness of the substrate layer (101) is 30 - 50 cm, and it is laid on the surface layer of the riparian zone to adsorb suspended solids and dissolved pollutants in runoff; The vegetation layer (102) is planted above the substrate layer (101) and is composed of pollution - tolerant herbaceous plants and shrubs distributed in a staggered belt. The depth of the plant roots is not less than 1.5 times the thickness of the substrate layer (101); The diversion structure (103) is arranged on the downstream side of the vegetation layer (102), including an adjustable - angle diversion plate (1031) and a bottom water - collecting trough (1032). The surface of the diversion plate is covered with a biofilm carrier material; The permeable dam body (104) is located downstream of the diversion structure (103) and is formed by stacking gravel and ecological concrete blocks. It is internally provided with multiple vertical - flow filtration channels filled with pyrite - limestone composite fillers; The monitoring module (105) includes a flow sensor (1051) arranged at the entrance of the diversion structure (103), a water quality monitoring probe (1052) in the substrate layer (101), and a turbidity sensor (1053) at the outlet of the permeable dam body (104); The grit chamber (106) is located downstream of the permeable dam body (104). The bottom of the chamber is sloped and is provided with a sand - discharging pipe (1061), and submerged plants are planted in the chamber; The flexible enclosure (107) is arranged at the junction of the grit chamber (106) and the river channel and is composed of a high - density polyethylene net and an ecological floating bed. Emergent plants are planted on the floating bed.

2. The ecological buffer interception system for river banks to prevent the spread of non-point source pollution according to claim 1, characterized in that, The angle between the diversion plate (1031) of the diversion structure (103) and the ground can be electrically adjusted within the range of 15° - 60°. The surface of the diversion plate (1031) is provided with a honeycomb - shaped polyethylene carrier layer, and the carrier layer is inoculated with a composite bacterium agent of denitrifying bacteria and polyphosphate - accumulating bacteria.

3. The ecological buffer interception system for a riverbank to prevent the spread of non-point source pollution according to claim 1, wherein The pyrite - limestone composite fillers filled in the vertical - flow filtration channels of the permeable dam body (104) have a particle size of 5 - 20 mm, the mass ratio of pyrite to limestone is 1:2 - 1:4, and the total height of the filler layer accounts for 2 / 3 of the height of the permeable dam body (104).

4. The ecological buffer interception system for river banks to prevent the spread of non-point source pollution according to claim 1, characterized in that, The monitoring module (105) is communicatively connected to the central controller. The central controller dynamically adjusts the angle of the diversion plate (1031) and the internal water flow distribution ratio of the permeable dam body (104) according to the real - time monitored flow rate and pollutant concentration data.

5. An ecological buffer interception system for a river bank to prevent the spread of non-point source pollution according to claim 1, characterized in that, The outlet of the sand - discharging pipe (1061) of the grit chamber (106) is connected to a sludge drying bed. A sand - filtration layer and an earthworm decomposition area are laid in the drying bed, and the dried sediment is backfilled into the substrate layer (101).

6. The ecological buffer interception system for a riverbank to prevent the spread of non-point source pollution according to claim 1, characterized in that, The ecological floating bed of the flexible enclosure (107) is composed of modified PVC pipes spliced into a grid-shaped framework. The framework is filled with coconut shell fiber matrix, and the planting density of emergent plants is 20-30 plants / m 2 .

7. The ecological buffer interception system for river banks to prevent the spread of non-point source pollution according to claim 1, characterized in that, An anti-seepage isolation layer is further provided below the matrix layer (101), which is composed of a composite of bentonite and geotextile, with a thickness of 10-15 cm and an anti-seepage coefficient ≤ 1×10 -7 cm / s.

8. An ecological buffer interception method for riverbank zones to prevent the spread of non-point source pollution, characterized in that, It includes the following steps: The first step, topographic survey and system design: According to the slope of the riparian zone, the surface runoff path and historical pollution data, determine the laying range of the substrate layer, the installation position of the diversion structure and the height of the permeable dam body; The second step, construction of the substrate layer and the vegetation layer: Mix straw fiber, zeolite and humus soil according to the ratio to form the substrate layer. After compaction, plant pollution - tolerant plants, and initially use a drip irrigation system to maintain soil moisture; Step 3, Debugging of the diversion structure and the permeable dam body: Set the initial angle of the deflector to 30°, and pre-fill the vertical flow channel of the permeable dam body with water to activate the microbial community; Step 4, System operation and dynamic regulation: Obtain data on flow rate, turbidity, and nitrogen and phosphorus concentrations through the monitoring module. When the pollutant load exceeds the threshold, the central controller increases the angle of the deflector to 45° - 60°, and increases the water flow distribution in the western channel of the permeable dam body; Step 5, Maintenance and management: Clean the sediment in the grit chamber every quarter and backfill it into the drying bed, and prune the vegetation layer and supplement the humus soil in the substrate layer every winter.

9. A method for ecological buffer interception of riverbanks to prevent the spread of non-point source pollution according to claim 8, characterized in that, The specific logic of the dynamic regulation described in Step 4 is as follows: When the flow sensor detects that the runoff increases by more than 50% and lasts for 10 minutes, the angle of the deflector is increased to 50°; When the water quality monitoring probe detects that the ammonium nitrogen concentration exceeds 2 mg / L, the eastern channel of the permeable dam body is closed, forcing the water to flow through the western high-pyrite proportion filler area; When the value of the turbidity sensor exceeds 50 NTU, the sand discharge pipe of the grit chamber is automatically triggered to open.

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