Device for controlling non-point source pollution from source and design method

Abstract

The invention discloses a device for controlling non-point source pollution from a source and a design method. The device comprises a shallow pool (1) and a deep pool (2) which are arranged in parallel, the shallow pool (1) is connected to a drainage ditch or an intercepting ditch, the shallow pool (1) is provided with a water inlet and a water outlet, the shallow pool (1) and the deep pool (2) are separated by a partition wall, and the bottom of the partition wall is provided with a communication port (3); the automatic shunting control device comprises a gravity sealing mechanism arranged on the shallow pool side, a water level triggering mechanism arranged on the deep pool side and a traction mechanism for connecting the gravity sealing mechanism and the water level triggering mechanism; the gravity sealing mechanism is used for opening and closing the communicating port; basic data are collected; determining a target control area and an initial design rainfall depth; calculating the effective volume required by the deep pool; determining the structural sizes of the deep pool and the shallow pool; and determining the triggering water level of the water level triggering mechanism. The problems that in the prior art, stable interception cannot be achieved for pollution cores, and the cyclic agricultural requirement of pollutant resource recycling cannot be met are solved.

Description

Technical Field

[0001] This invention belongs to the field of agricultural non-point source pollution control technology, and particularly relates to a device and design method for controlling non-point source pollution at its source. Background Technology

[0002] Agricultural non-point source pollution is a major external input leading to eutrophication of water bodies. Nutrients in farmland and orchards are mainly transported through rainfall runoff and the sediment it carries. This type of pollution output exhibits a significant initial flushing effect, with pollutants from a single rainfall event concentrated in the early stages of runoff generation. The concentration of pollutants in this portion of runoff sediment is extremely high, making it a key focus of pollution control.

[0003] Currently widely adopted end-of-pipe interception measures, such as ecological drainage ditches and vegetated buffer zones, are severely inadequate in addressing this critical issue. While these measures can promote some sediment deposition by slowing flow velocity, nutrients deposited in the ditches are not effectively removed or recycled. In subsequent rainfall, especially strong scouring events, these nutrients are easily washed afresh and transported downstream, meaning pollutants are not truly intercepted, and nutrient return to the fields is impossible, resulting in continuous resource loss. Secondly, the effectiveness of such facilities declines rapidly with sediment accumulation, leading to high maintenance costs and a lack of sustainability. Existing technologies cannot identify, separate, and specifically treat high-pollution initial runoff; instead, they passively mix extremely high-concentration initial runoff with later, cleaner runoff, severely diluting the pollution front, reducing overall interception efficiency, and lacking the possibility of recycling high-concentration nutrients.

[0004] Therefore, existing technological systems are unable to achieve stable interception of pollution at its core, nor can they meet the needs of circular agriculture for the resource recovery of pollutants. Summary of the Invention

[0005] The technical problem to be solved by this invention is to provide a device and design method for controlling non-point source pollution at its source, so as to solve the technical problems that the existing technology system can neither achieve stable interception of pollution cores nor meet the needs of circular agriculture for the resource recovery of pollutants.

[0006] The technical solution of this invention is:

[0007] A device for controlling non-point source pollution at its source includes a shallow pool and a deep pool arranged in parallel. The shallow pool is connected to a drainage ditch or intercepting ditch and has an inlet and an outlet. The shallow pool and the deep pool are separated by a partition wall, and a connecting port is opened at the bottom of the partition wall. An automatic diversion control device includes a gravity sealing mechanism disposed on the side of the shallow pool, a water level triggering mechanism disposed on the side of the deep pool, and a traction mechanism connecting the two. The gravity sealing mechanism is used to open and close the connecting port.

[0008] The gravity sealing mechanism includes a sealing plate, a guide section, and a guide assembly. The guide section is fixed directly above the sealing plate. The guide assembly is a vertical guide sleeve fixed on the inner wall of the shallow pool. The sealing plate and the guide section are set inside the vertical guide sleeve and slide in cooperation with the vertical guide sleeve to realize the sealing plate and the guide section moving up and down along the vertical guide sleeve. A sealing gasket is provided at the bottom of the sealing plate.

[0009] The water level triggering mechanism includes a lever, a float fixed to one end of the lever, and a hook fixed to the other end of the lever; the float is located near the inner wall of the deep pool; the lever is fixed to the inner wall of the deep pool by a bracket.

[0010] The traction mechanism includes a chain, one end of which is connected to the guide of the gravity sealing mechanism, and the other end of which passes through the chain hole in the partition wall and is hung on a hook; a limit stop is provided on the chain.

[0011] The method includes:

[0012] Step 1: Collect basic data;

[0013] Step 2: Determine the target control area and the initial design rainfall depth;

[0014] Step 3: Calculate the required effective volume of the deep pool;

[0015] Step 4: Determine the structural dimensions of the deep pool;

[0016] Step 5: Determine the structural dimensions of the shallow pool;

[0017] Step 6: Determine the trigger water level of the water level triggering mechanism.

[0018] The basic data includes: meteorological and hydrological data, underlying surface data, and pollution load data; the meteorological and hydrological data includes daily rainfall data for at least 10 consecutive years; the underlying surface data includes the area of ​​the catchment area, land use type, soil type, and runoff coefficient; the pollution load data includes regional fertilization level and soil background nitrogen and phosphorus content, or monitoring data of initial runoff pollutant concentration in similar areas.

[0019] The method for determining the target control area is as follows: clearly define the catchment area of ​​the farmland being served; the method for determining the initial design rainfall depth is as follows: use "initial 10-15 mm rainfall" or "rainfall in the first 30 minutes of the initial rainfall" as the design value.

[0020] The method for calculating the required effective volume of a deep pool is as follows:

[0021] V deep = i × A × ψ;

[0022] In the formula: V deepdenoted as , where i is the required effective volume of the deep pool; is the initial design rainfall depth; A is the catchment area; and ψ is the comprehensive runoff coefficient.

[0023] The method for determining the structural dimensions of the deep pool is as follows:

[0024] Calculate the bottom area S of the pool deep :S deep = V deep / H deep ;

[0025] Determine the plan dimensions: Based on the site topography, determine the pool length L. deep With pool width W deep Satisfying L deep × W deep =S deep The aspect ratio is between 1.5:1 and 3:1;

[0026] In the formula: V deep H is the effective volume required for the deep pool. deep For effective water depth.

[0027] Methods for determining the trigger water level of the water level triggering mechanism include:

[0028] H trigger = V deep / S deep；

[0029] H trigger To trigger the water level, V deep H is the effective volume required for the deep pool. deep The effective water depth; based on the calculated trigger water level H trigger In the automatic diversion control device, the water level triggering mechanism is set with a pre-defined float position so that when the actual water level in the deep pool reaches the trigger level Htrig... ger At that time, the buoyancy-driven automatic diversion control device closes the connection port.

[0030] The beneficial effects of this invention are:

[0031] This invention achieves source separation and precise interception of polluted runoff: through an automatic cut-off device, the initial and later runoff with huge differences in pollution load are physically separated, and high-concentration pollutants are sealed in a deep pool, which greatly improves the targeting and efficiency of pollution interception and provides high-quality raw materials for the production of liquid fertilizer or compost.

[0032] Reliable operation and low maintenance costs: The entire system operates on a purely mechanical principle, requiring no external power or complex control system, making it adaptable to harsh outdoor environments. The deep pool closes once full, significantly reducing the frequency of dredging; main maintenance is concentrated in the shallow pool, resulting in simple and economical overall operation and maintenance.

[0033] Simple structure and sturdy and durable: The main components of the device are all rigid metal parts, which are not easily deformed, worn or affected by mud and sand, and have a long service life.

[0034] This invention features a scientific design, providing a design method that quantitatively correlates key facility parameters with local meteorological, hydrological, and topographical conditions. This transforms the design from "experience-based design" to "scientific design," ensuring the stable and efficient operation of the facility and enabling it to flexibly adapt to the complex needs of different regions and plots of land. It has high potential for widespread application.

[0035] It solves the technical problems that existing technology systems cannot achieve stable interception of pollution cores, nor can they meet the needs of circular agriculture for the resource recovery of pollutants. Attached Figure Description

[0036] Figure 1 This is a schematic diagram of the structure of the source control device for non-point source pollution of the present invention;

[0037] Figure 2 This is a three-dimensional structural diagram of the water level triggering mechanism.

[0038] Figure 3 This is a three-dimensional structural diagram of a gravity sealing mechanism.

[0039] The numbers in the diagram are as follows: 1 is the shallow pool, 2 is the deep pool, 3 is the connecting port, 4 is the sealing plate, 5 is the vertical guide sleeve, 6 is the guide section, 7 is the limiting block, 8 is the chain, and 9 is the float. Detailed Implementation

[0040] A design method for a source control device for non-point source pollution includes:

[0041] Step 1: Collect and analyze basic data:

[0042] Meteorological and hydrological data: Daily rainfall data for at least 10 consecutive years, used to analyze rainfall characteristics.

[0043] Underlying surface data: Catchment area (A, m²) 2 ), land use type, soil type and runoff coefficient (ψ).

[0044] Pollution load data: regional fertilization levels, soil background nitrogen and phosphorus content, or monitoring data on initial runoff pollutant concentrations in similar areas.

[0045] Step 2: Determine the target control area and the initial design rainfall depth (i):

[0046] Delineate the catchment area: Define the catchment area (A, m) of the farmland served by the device. 2 This area should have a relatively uniform land use and fertilization pattern.

[0047] Determining the "initial runoff" control: The core is determining the "initial design rainfall depth (i)", which represents the initial rainfall amount that this invention aims to effectively intercept, corresponding to runoff carrying the majority of pollutants. Consult hydrological manuals or relevant research literature on agricultural non-point source pollution in the project area. "Initial 10-15 mm rainfall" or "rainfall in the first 30 minutes of the initial rainfall" can be adopted as the design value. For example, if research shows that 70% of the local pollution load is carried by the runoff from the first 12 mm of rainfall, then i can be taken as 12 mm.

[0048] Step 3: Calculate the required effective volume (V) of the deep pool. deep ):

[0049] Used to store all contaminated runoff generated from the initial design rainfall.

[0050] The calculation formula is: V deep = i × A × ψ

[0051] In the formula: V deep Required effective volume of deep pool (m³) 3 );

[0052] i. Initial design rainfall depth (m);

[0053] A. Catchment area (m²) 2 );

[0054] ψ is the comprehensive runoff coefficient (determined by referring to a table based on the surface type of the catchment area, such as dry land, paddy field, or bare soil. For example, 0.2-0.4 can be used for leveled farmland, and 0.4-0.6 can be used for sloping farmland).

[0055] Step 4: Determine the structural dimensions of the deep pool:

[0056] According to V deep Determine the geometric dimensions of the pool.

[0057] Select effective water depth (H) deep Considering both sedimentation efficiency and construction safety, a value range of 0.6-0.8m is recommended.

[0058] Calculate the bottom area of ​​the pool (S) deep ):S deep = V deep / H_deep.

[0059] Determine the plan dimensions: Based on the site topography, determine the pool length (L). deep ) and pool width (W deep ), satisfying L deep × W deep =S deepThe aspect ratio should be between 1.5:1 and 3:1.

[0060] Step 5: Determine the structural dimensions of the shallow pool:

[0061] Shallow pools are used to treat cleaner runoff in the later stages, and their size should meet the requirements for sedimentation and flow.

[0062] Estimate the volume of the shallow pool (V) shallow V can be deducted based on the total runoff of a typical complete rainfall event (e.g., a 1-year return period). deep Then, take into account the hydraulic residence time (20-30 minutes is recommended) in the calculation.

[0063] Determine the effective water depth (H) of the shallow pool shallow The recommended depth is 0.4-0.6m.

[0064] Shallow pool bottom area: To facilitate construction, the length and width of the shallow pool should be the same as those of the deep pool.

[0065] Set key elevations: The elevation of the overflow weir at the outlet of the shallow pool must be higher than the elevation of the inlet of the connecting pipe at the bottom of the partition wall to ensure that the hydraulic flow preferentially flows to the deep pool.

[0066] Step 6: Determine the trigger water level of the water level triggering mechanism:

[0067] Calculate the trigger water level (H) trigger ): That is, the deep pool is designed to be filled to the full water level, H trigger = V deep / S deep .

[0068] Device adjustment settings: based on the calculated H trigger In the water level triggering mechanism of the automatic diversion control device, the installation position of the preset float ensures that when the actual water level in the deep pool reaches Htrig... ger At that time, the buoyancy is just enough to drive the automatic diversion control device to close the connection port.

[0069] Step 7: Create integrated design drawings:

[0070] Based on all the parameters determined in the above steps, draw up construction design drawings that include the pool's plan layout, cross-sectional structure, detailed drawings of the automatic diversion control device, and water flow path.

[0071] A device for controlling non-point source pollution at its source, comprising:

[0072] A shallow pool 1 and a deep pool 2 are connected in parallel. The shallow pool 1 is connected to a drainage ditch or intercepting ditch and is equipped with an inlet and an outlet. The shallow pool 1 and the deep pool 2 are separated by a partition wall, and a connecting opening 3 is opened at the bottom of the partition wall to connect the two pools at the bottom.

[0073] The source control device for non-point source pollution also includes an automatic diversion control device. The automatic diversion control device includes a gravity sealing mechanism installed on the shallow pool side, a water level triggering mechanism installed on the deep pool side, and a traction mechanism connecting the two.

[0074] A gravity sealing mechanism is used to open and close the connection port 3. It includes a sealing plate 4. To ensure that the sealing plate 4 falls precisely and vertically to cover the connection port 3, the gravity sealing mechanism also includes a guide assembly. The guide assembly includes a vertical guide sleeve 5 fixed to the inner wall of the shallow pool, the sealing plate 4, and a guide section 6 fixed to the upper side of the sealing plate 4. The sealing plate 4 and the guide section 6 are disposed within the vertical guide sleeve 5 and slide in cooperation with it, enabling the sealing plate 4 and the guide section 6 to move vertically up and down along the vertical guide sleeve 5, preventing the sealing plate and guide section from shifting or tilting. A sealing gasket is provided at the bottom of the sealing plate 4.

[0075] The water level triggering mechanism is used to sense the water level in the deep pool and trigger an action. The water level triggering mechanism includes a lever, a float 9 fixed to one end of the lever, and a hook fixed to the other end of the lever.

[0076] The lever is fixed to the inner wall of the deep pool by a bracket.

[0077] The traction mechanism is a chain 8. One end of the chain 8 is connected to the guide section 6 of the gravity sealing mechanism, and the other end passes through the chain hole in the partition wall and can be released and hung on a hook. A limit stop 7 is set on the chain 8. When the sealing plate 4 falls to the sealing position, the limit stop 7 is locked at the chain hole on the deep pool side to prevent the chain 8 from being excessively released.

[0078] The facility operates as follows:

[0079] Initial / Inlet State: The water level in the deep pool is low, the float 9 sinks, the hook end of the lever is in a high position, the chain 8 is tightened, the sealing plate 4 is pulled away from the connecting port, and the channel is opened. Initially, all high-concentration runoff enters the deep pool for storage through the connecting port 3.

[0080] Trigger / Close Status: When the water level in the deep pool rises to the preset height, float 9 rises, causing the lever to rotate, the hook end to descend, and the chain to be released. Under its own weight, sealing plate 4 falls vertically along the guide assembly, its bottom sealing gasket tightly covering the connecting opening, completely cutting off the channel. Cleaner runoff will then only be able to settle in the shallow pool before being discharged from the outlet.

[0081] Manual reset: During the off-season, the nutrient-rich muddy water in the deep pool is returned to the field, and the chain is manually reattached to the hook, and the sealing plate is lifted and reset to prepare for the next rainfall.

Claims

1. A device for controlling pollution from a source, characterized in that: The device comprises shallow pool (1) and deep pool (2) arranged in parallel; the shallow pool (1) is connected to the drainage ditch or the water interception ditch, the shallow pool (1) is provided with a water inlet and a water outlet, the shallow pool (1) and the deep pool (2) are separated by a partition wall, and a communication port (3) is formed in the bottom of the partition wall; the automatic diversion control device comprises a gravity sealing mechanism arranged on the shallow pool side, a water level triggering mechanism arranged on the deep pool side and a traction mechanism connecting the two; the gravity sealing mechanism is used for opening and closing the communication port (3).

2. The device for controlling pollution of a source according to claim 1, characterized in that: The gravity sealing mechanism comprises a sealing plate (4), a guide section (6) and a guide assembly, the guide section (6) is fixed above the sealing plate (4); the guide assembly is a vertical guide sleeve (5) fixed on the inner wall of the shallow pool, the sealing plate (4) and the guide section (6) are arranged in the vertical guide sleeve (5) and are in sliding fit with the vertical guide sleeve (5), so that the sealing plate (4) and the guide section (6) move up and down along the vertical guide sleeve (5); the bottom of the sealing plate (4) is provided with a sealing gasket.

3. The device for controlling pollution of a source according to claim 1, characterized in that: The water level triggering mechanism comprises a lever, a floating ball (9) fixed at one end of the lever and a hook fixed at the other end of the lever; the floating ball (9) is close to the inner side wall end of the deep pool; the lever is fixed on the inner side wall of the deep pool through a support.

4. The device for controlling pollution of a source according to claim 3, characterized in that: The traction mechanism comprises a chain (8), one end of the chain (8) is connected with the guide section (6) of the gravity sealing mechanism, the other end of the chain (8) passes through a chain passing hole on the partition wall and is hung on the hook; a limiting stopper (7) is arranged on the chain (8).

5. The method of designing a device for controlling pollution from a source of surface contamination as claimed in claim 1, wherein: The method comprises: Step 1, collecting basic data; Step 2, determining target control area and initial design rainfall depth; Step 3, calculating effective volume required by the deep pool; Step 4, determining the structure size of the deep pool; Step 5, determining the structure size of the shallow pool; Step 6, determining the triggering water level of the water level triggering mechanism.

6. The method of claim 5, wherein the device is designed to control pollution from a source of surface water. The basic data comprises meteorological and hydrological data, underlying surface data and pollution load data; the meteorological and hydrological data comprises daily rainfall data for at least 10 consecutive years; the underlying surface data comprises the area of the catchment area, the land use type, the soil type and the runoff coefficient; the pollution load data comprises the regional fertilization level and the background nitrogen and phosphorus content of the soil, or the monitoring data of the initial runoff pollutant concentration of the similar region.

7. The method of claim 5, wherein the device is designed to control pollution from a source of surface water. The determination method of the target control area is to determine the farmland catchment area served; the determination method of the initial design rainfall depth is to adopt "initial 10-15 mm rainfall" or "rainfall amount in the first 30 minutes of rainfall" as the design value.

8. The method of claim 5, wherein the device is designed to control pollution from a source of surface water. The calculation method of the effective volume required by the deep pool is: V deep = i × A × ψ; where: V deep is the effective volume required for a deep pool; i is the initial design rainfall depth; A is the catchment area; and ψ is the combined runoff coefficient.

9. The method of claim 5, wherein the device is designed to control pollution from a source of surface water. The determination method of the structure size of the deep pool is: Calculate the bottom area S of the pool deep : S deep = V deep / H deep ; Determine the plan size: according to the site topography, determine the pool length L deep and the pool width W deep , meet L deep × W deep = S deep , the length-width ratio is between 1.5:1 and 3:1; where: V deep is the effective volume required for a deep pool, H deep is the effective water depth.

10. The method of claim 5, wherein the device is designed to control pollution from a source of surface water. The method for determining the triggering water level of the water level triggering mechanism comprises: H trigger = V deep / S deep； H trigger Htrig deep Htrig deep Htrig trigger Htrig ger Htrig

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