Synergistic recycling device and method for domestic sewage and paddy field drainage

Abstract

The invention relates to the technical field of agricultural water resource utilization, in particular to a domestic sewage and paddy field drainage collaborative recycling device and method.The device comprises an irrigation channel, a plurality of electric micro gates and water level gauges are arranged on the two sides of the irrigation channel and correspond to farmlands; the water level gauge is located in the middle of the farmland and used for measuring the water level of the farmland in real time; the drainage ditch is arranged on the side, away from the irrigation channel, of the farmland, the drainage ditch is provided with a plurality of drainage ports corresponding to the farmland, one end of each drainage port is communicated with the pond, a plurality of height-adjustable overflow weirs are arranged in the drainage ditch, and a plurality of submersible pumps communicated with the farmland are further arranged in the drainage ditch. The submersible pump is powered by a solar power supply system; according to the invention, the efficient utilization of water resources is realized, the domestic sewage is recycled for pollution control, the energy and agricultural production cost is reduced, and the synergistic effects of water saving, energy saving and environmental protection are achieved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of agricultural water resource utilization, in particular to a domestic sewage and paddy field drainage collaborative recycling device and method. BACKGROUND

[0002] In current agricultural production, the contradiction between water supply and demand is increasingly prominent. Farmland irrigation has long relied on conventional water sources such as groundwater and river and lake water. Overexploitation has led to problems such as declining groundwater levels and imbalanced water resources in river basins. At the same time, the efficiency of agricultural water use is low. Traditional flooding irrigation not only wastes water resources but also easily causes secondary salinization of soil. At the same time, domestic sewage in rural areas is directly discharged or discharged after simple treatment, polluting the surrounding water environment and wasting water resources. Paddy field drainage contains certain nitrogen and phosphorus nutrients. Direct discharge not only wastes resources but also may exacerbate water eutrophication.

[0003] Existing farmland irrigation systems lack intelligent control capabilities and cannot accurately supply water according to the water requirements of crop growth periods. No collaborative recycling mechanism has been established for domestic sewage and paddy field drainage, making it difficult to achieve water resource recycling. Some recycling technologies only treat domestic sewage or recover paddy field drainage, which has low treatment efficiency, poor adaptability, and relies on external energy, and cannot meet the dual needs of efficient use of water resources and ecological environment protection for agricultural green development.

[0004] For example, the prior art CN204670041U discloses a control system for agricultural irrigation using domestic sewage, proposing an automatic control device that connects the domestic sewage treatment pond to the irrigation pipeline, and the pump valve to the clean water backup circuit. Although this method realizes the automatic connection of domestic sewage to agricultural irrigation, its essence is still mainly based on the direct supply of treated effluent, which increases the dependence on effluent stability, electric drive, and on-site maintenance. If the effluent fluctuates or the operation and maintenance is not in place, it may lead to the runaway of pathogens or nutrient load and exacerbate irrigation safety hazards. Prior art CN104355410A and CN104355410B disclose a non-point source interception and blocking system with ecological ditches and paddy field wetlands as the core. Although this passive wetland / interception method plays a role in reducing non-point source nitrogen and phosphorus emissions and improving the resource utilization of wastewater, the wetland treatment efficiency is greatly affected by climate, residence time, substrate and plant configuration, and the stable removal capacity of trace organic pollutants and pathogens is limited. Therefore, it is poorly adaptable to grain production scenarios that require strict water quality protection and extensive irrigation applications. Existing technologies such as CN102817337A, CN104445831A, and CN104773835B disclose various paddy field drainage control devices, household / decentralized integrated systems for domestic sewage treatment and reuse, and field fixed-point drainage wetland construction systems. Although each of these technologies partially solves the practical operational problems of single-source reuse or drainage purification, their solutions generally tend to be single-function modules (such as only treating domestic sewage or only intercepting paddy field drainage). They lack the complete realization of real-time coordinated allocation of domestic sewage effluent and paddy field drainage within the same engineering device, intelligent water supply strategies based on the growth period, and low-energy off-grid / regional time-based operation. Therefore, they are prone to causing the quality of reused water / water supply timing to be out of sync with crop water requirements, increased energy consumption and maintenance costs, and increased risks in field operation.

[0005] Therefore, given the functional gaps and engineering limitations reflected in the aforementioned patents, it is necessary to propose an engineering device and method that can achieve real-time coordinated allocation of water quantity and quality under dual constraints between domestic sewage treatment effluent and paddy field drainage at the field level, intelligent water supply control based on crop growth stages, hierarchical online safety assurance, and low-energy off-grid operation, in order to fill the gaps in existing technologies in terms of intelligence, multi-source coupling, and sustainable operation. Summary of the Invention

[0006] In view of this, the present invention addresses the shortcomings of the prior art by proposing a device and method for the coordinated reuse of domestic sewage and paddy field drainage, aiming to solve at least one of the problems mentioned in the background art.

[0007] In a first aspect, the present invention provides a device for the coordinated reuse of domestic sewage and paddy field drainage, comprising:

[0008] An irrigation canal is connected at one end to a water source and a domestic sewage treatment pond. Multiple electric micro-gates and water level gauges are installed on both sides of the irrigation canal corresponding to the farmland. The electric micro-gates are located at the head of the farmland and automatically start and stop to achieve automatic irrigation of the farmland. The water level gauges are located in the middle of the farmland and are used to measure the water level of the farmland in real time.

[0009] A drainage ditch is provided on the side of the farmland away from the irrigation canal. The drainage ditch has multiple drainage outlets corresponding to the farmland. One end of each drainage outlet is connected to a pond. The drainage ditch is equipped with multiple adjustable-height overflow weirs. The drainage ditch is also equipped with multiple submersible pumps connected to the farmland. The submersible pumps are powered by a solar power system.

[0010] In some embodiments, the domestic sewage treatment pond is connected to the irrigation channel via the submersible pump.

[0011] In some embodiments, the water level gauge is installed inside the sewage treatment tank and the pond.

[0012] In some embodiments, the drainage ditch is provided with a plurality of adjustable height overflow weirs, and a water storage tank is formed between the plurality of adjustable height overflow weirs. The top of the adjustable height overflow weir is provided with a V-shaped opening.

[0013] In some embodiments, the solar power system is electrically connected to the electric microgate, submersible pump, and water level gauge, respectively.

[0014] Secondly, the present invention provides a method for the co-reuse of domestic sewage and paddy field drainage, comprising the following steps:

[0015] The water level in the farmland is measured in real time by the water level gauge in the farmland. The water level is then combined with the water balance principle and the water requirements of crops at different growth stages to determine whether the farmland needs irrigation. When the farmland needs irrigation, the current irrigation amount of the farmland is obtained.

[0016] The system obtains the sewage storage volume in the domestic sewage treatment pond, the rainfall forecast for the current farmland area in the next 3-5 days, and irrigates the farmland based on the sewage storage volume in the domestic sewage treatment pond, the rainfall forecast for the current farmland area in the next 3-5 days, and the drainage volume of the paddy field drainage ditch.

[0017] In some embodiments, the step of measuring the water level of the farmland in real time using a water level gauge, and determining whether the farmland needs irrigation based on the principle of water balance and the water requirements of crops at different growth stages, and obtaining the current irrigation amount of the farmland when irrigation is needed, includes:

[0018] A preset water level threshold is set in the farmland. When the water level in the farmland is lower than the water level threshold, it is determined that the farmland needs irrigation, and the current irrigation amount of the farmland is obtained based on the area of ​​the farmland.

[0019] In some embodiments, obtaining the sewage storage volume in the domestic sewage treatment pond, obtaining the rainfall forecast for the area where the farmland is located in the next 3-5 days, and irrigating the farmland based on the sewage storage volume in the domestic sewage treatment pond and the rainfall forecast for the area where the farmland is located in the next 3-5 days includes:

[0020] The sewage storage volume in the sewage treatment tank is obtained according to the water level gauge in the sewage treatment tank. The sewage in the sewage treatment tank is then transferred to the interior of the irrigation canal by a submersible pump in the sewage treatment tank, and then transferred to the interior of the farmland by a submersible pump on the irrigation canal.

[0021] In some embodiments, when obtaining the sewage storage volume in the domestic sewage treatment pond, obtaining the rainfall forecast for the area where the farmland is located in the next 3-5 days, and irrigating the farmland based on the sewage storage volume in the domestic sewage treatment pond and the rainfall forecast for the area where the farmland is located in the next 3-5 days, the method further includes:

[0022] When the sewage storage volume in the sewage treatment pond is greater than or equal to the current irrigation volume of the farmland, the domestic sewage in the sewage treatment pond is transferred to the farmland for irrigation.

[0023] When the sewage storage volume in the sewage treatment pond is less than the current irrigation volume of the farmland, the domestic sewage in the sewage treatment pond is transferred to the farmland, and it is determined whether the sum of the water volume in the water storage tank and the sewage storage volume in the sewage treatment pond meets the current irrigation volume of the farmland.

[0024] In some embodiments, when obtaining the sewage storage volume in the domestic sewage treatment pond, obtaining the rainfall forecast for the area where the farmland is located in the next 3-5 days, and irrigating the farmland based on the sewage storage volume in the domestic sewage treatment pond and the rainfall forecast for the area where the farmland is located in the next 3-5 days, the method further includes:

[0025] When the total amount of water in the water storage tank and the amount of sewage stored in the domestic sewage treatment pond meets the current irrigation demand of the farmland, the water in the water storage tank is transferred to the farmland for irrigation.

[0026] When the total amount of water in the water storage tank and the amount of sewage stored in the domestic sewage treatment pond is insufficient to meet the current irrigation needs of the farmland, the water in the water storage tank is transferred to the farmland, and the water in the pond is transferred to the water storage tank by the submersible pump, and then pumped into the farmland by the submersible pump inside the water storage tank for irrigation.

[0027] Compared with existing technologies, the beneficial effects of this invention are as follows: This invention reuses treated domestic sewage and paddy field drainage in a coordinated manner, reducing dependence on conventional water sources such as groundwater, rivers, and lakes, avoiding the problems of groundwater level decline and water resource imbalance caused by over-exploitation, while replacing traditional flood irrigation, improving agricultural water use efficiency, and reducing water waste. By recycling rural domestic sewage, its direct discharge and water pollution are avoided; recycling paddy field drainage can reduce the direct discharge of nitrogen and phosphorus-containing water bodies, reducing the risk of eutrophication, achieving a dual cycle of water and nutrient resources, and protecting the ecological environment. Real-time monitoring of farmland water levels using water level gauges, combined with the water requirements of crops at different growth stages and the principle of water balance, uses an electric micro-gate to automatically start and stop irrigation, solving the problem of inaccurate water supply in existing systems and meeting the precise water needs of crop growth. A solar power system is used to power submersible pumps and other equipment, reducing dependence on external energy; an adjustable-height overflow weir forms a water storage tank to store water resources, combined with a pond water replenishment mechanism, ensuring a stable irrigation water source, achieving integrated resource recycling, and meeting the needs of green agricultural development.

[0028] The above general description and the following detailed description are exemplary and explanatory only, and are not intended to limit this disclosure.

[0029] Other features and aspects of this disclosure will become clearer from the following detailed description of exemplary embodiments with reference to the accompanying drawings. Attached Figure Description

[0030] To more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0031] Fig. 1 A plan view of the device for the coordinated reuse of domestic sewage and paddy field drainage provided in an embodiment of the present invention;

[0032] Fig. 2 A flowchart illustrating the method for the coordinated reuse of domestic sewage and paddy field drainage provided in an embodiment of the present invention.

[0033] The components include: 1. Irrigation canals; 2. Water sources; 3. Domestic sewage treatment ponds; 4. Farmland; 5. Electric micro-gates; 6. Water level gauges; 7. Ponds; 8. Drainage ditches; 9. Drainage outlets; 10. Submersible pumps; 11. Solar power supply systems; 12. Adjustable height overflow weirs; and 13. Water storage tanks. Detailed Implementation

[0034] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of this application, and not all of the embodiments. Based on the embodiments of this application, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of this application.

[0035] In the description of this application, it should be understood that the terms "center", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this application.

[0036] The terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Therefore, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this application, unless otherwise stated, "a plurality of" means two or more.

[0037] In the description of this application, it should be noted that, unless otherwise expressly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection between two components. Those skilled in the art can understand the specific meaning of the above terms in this application based on the specific circumstances.

[0038] See Figs. 1-2 As shown, in the first embodiment, a device for the co-reuse of domestic sewage and paddy field drainage according to an embodiment of this application includes:

[0039] An irrigation canal 1 is connected at one end to a water source 2 and a domestic sewage treatment pond 3. Multiple electric micro gates 5 and water level gauges 6 are respectively installed on both sides of the irrigation canal 1 corresponding to the farmland 4. The electric micro gates 5 are located at the head of the farmland 4 and automatically irrigate the farmland 4 by starting and stopping automatically. The water level gauges 6 are located in the middle of the farmland 4 and are used to measure the water level of the farmland 4 in real time.

[0040] A drainage ditch 8 is located on the side of the farmland 4 away from the irrigation canal 1. The drainage ditch 8 is provided with multiple drainage outlets 9 corresponding to the farmland 4. One end of each drainage outlet 9 is connected to a pond 7. Multiple adjustable-height overflow weirs 12 are provided in the drainage ditch 8. Multiple submersible pumps 10 connected to the farmland 4 are also provided in the drainage ditch 8. The submersible pumps 10 are powered by a solar power system 11.

[0041] In some specific embodiments, the domestic sewage treatment pond 3 is connected to the irrigation channel 1 via the submersible pump 10.

[0042] In some specific embodiments, the water level gauge 6 is installed inside the domestic sewage treatment tank 3 and the pond 7.

[0043] In some specific embodiments, the drainage ditch 8 is provided with a plurality of adjustable height overflow weirs 12, and a water storage tank 13 is formed between the plurality of adjustable height overflow weirs 12. The top of the adjustable height overflow weir 12 is provided with a V-shaped opening.

[0044] In some specific embodiments, the solar power supply system 11 is electrically connected to the electric microgate 5, the submersible pump 10 and the water level gauge 6, respectively.

[0045] It should be understood that irrigation canal 1, as the core water conveyance channel, plays a crucial role in supplying irrigation water to farmland 4. One end of it is connected to water source 2 and domestic sewage treatment pond 3, thus constructing a dual water supply mode of "conventional water source + reclaimed water source". The specific working logic is as follows:

[0046] Dual water source access logic: On the one hand, water source 2 can be used as a traditional irrigation water source (such as river water, groundwater, etc.) to supply water to farmland in special circumstances (such as insufficient domestic sewage, extreme drought, etc.); on the other hand, the treated sewage that meets the standards after treatment in domestic sewage treatment pond 3 will be transported to irrigation canal 1 through submersible pump 10 (a specific submersible pump connected to domestic sewage treatment pond) to become the main reclaimed water source for farmland irrigation and realize the resource utilization of sewage.

[0047] Precision irrigation control for farmland: Each plot of farmland 4 is equipped with an electric micro-gate 5 and a water level gauge 6 on both sides of the irrigation canal 1, forming a precision control unit of "one field, one gate, one monitoring". The electric micro-gate 5 is installed at the head of the farmland 4 (i.e., the entrance for irrigation water to enter the farmland). Its opening and closing is automatically controlled by the system based on the monitoring data of the water level gauge 6: When the water level gauge 6 (located in the middle of the farmland and accurately reflects the overall water level of the farmland) detects that the farmland water level is lower than the preset threshold, the system determines that the farmland needs irrigation and then controls the electric micro-gate 5 to open, allowing water (domestic sewage or source water) in the irrigation canal to enter the farmland; when the water level gauge detects that the farmland water level has reached the preset suitable value, the system controls the electric micro-gate 5 to close, stopping irrigation, thereby realizing automatic and precise irrigation of farmland and avoiding water waste.

[0048] Drainage ditch 8 is located on the side of farmland 4 away from irrigation canal 1. Its main function is to collect excess drainage from the farmland and to achieve temporary storage, regulation, and secondary reuse of the drainage through a special structural design. The specific working mechanism is as follows:

[0049] Farmland drainage collection and preliminary regulation: Each plot of farmland 4 is equipped with a drainage outlet 9 for its corresponding drainage ditch 8. When excess water occurs after irrigation (e.g., due to excessively high water levels caused by combined rainfall and irrigation, or reduced water requirements in the later stages of crop growth), the excess water will flow into the drainage ditch 8 through the drainage outlet 9, preventing waterlogging from affecting crop growth. Simultaneously, the adjustable-height overflow weirs 12 within the drainage ditch 8 play a crucial regulatory role. In a specific embodiment, each drainage ditch 8 is equipped with two adjustable-height overflow weirs 12, forming a closed water storage tank 13 between them. The adjustable height design allows staff to adjust the overflow weir height according to actual needs (e.g., more water storage during the rainy season, rapid water replenishment during the dry season), thereby controlling the volume of the water storage tank 13. The V-shaped opening at the top of the overflow weir ensures a smooth flow of water into the water storage tank when the drainage flow is low, preventing water impact from causing siltation within the tank. Simultaneously, when the flow is high, the V-shaped opening allows for rapid drainage, preventing excessively high water levels in the drainage ditch from backflowing into the farmland.

[0050] Coordinated replenishment of drainage and reclaimed water sources: Multiple submersible pumps 10 connected to farmland 4 are installed in drainage ditch 8. These submersible pumps are powered by solar power system 11 (ensuring clean energy drive and reducing operating costs) and mainly undertake the function of "secondary water replenishment". When farmland needs irrigation, but the sewage storage capacity of domestic sewage treatment pond 3 is insufficient, the system will prioritize the use of farmland drainage collected in water storage tank 13: submersible pump 10 starts and pumps water from the water storage tank to the corresponding farmland 4 to supplement irrigation water; if the total amount of water in the water storage tank and sewage in the domestic sewage treatment pond is still insufficient to meet the irrigation needs of farmland, the system will control submersible pump 10 (submersible pump connected to pond 7, or submersible pump that can switch water intake targets) to pump water from pond 7, and transport rainwater, surface runoff and other water sources stored in the pond to the farmland, forming a three-level water source guarantee system of "domestic sewage as the main source, farmland drainage as the auxiliary source, and pond water for emergency use", maximizing the use of reclaimed water and natural precipitation and reducing dependence on traditional water sources.

[0051] The configuration of the solar power system 11 and the multi-scenario water level gauge 6 provides energy support and data assurance for the stable operation of the entire device.

[0052] The entire system is powered by clean energy: the solar power system 11 is electrically connected to the electric micro-gate 5, submersible pump 10, and water level gauge 6, providing continuous power to these devices. In farmland areas (where sunlight conditions are usually good), the solar panels can efficiently absorb solar energy and convert it into electricity to meet the daily operating needs of the equipment. This not only reduces the power cost of the device but also reduces carbon emissions from traditional fossil fuel power generation, aligning with green environmental protection principles. Simultaneously, the system is typically equipped with energy storage devices (such as batteries) to power the equipment during cloudy days and nighttime hours when there is no sunlight, ensuring stable operation of the device around the clock.

[0053] Full-process water level monitoring and data support: In addition to the water level gauge 6 in farmland 4, water level gauges 6 are also installed in the domestic sewage treatment pond 3 and the pond 7, forming a water level monitoring network covering the entire process from "water source-treatment pond-farmland-drainage ditch-pond". The water level gauge in the domestic sewage treatment pond is used to obtain the sewage storage volume in real time, providing data basis for the system to determine whether it can meet the irrigation needs of farmland; the water level gauge in the pond is used to monitor the water storage volume of the pond, ensuring that the pond water volume can be accurately grasped during emergency water replenishment, avoiding excessive water pumping that could cause the pond to dry up; the monitoring data of all water level gauges are transmitted to the system control center in real time, providing accurate data support for operations such as starting and stopping the electric micro-gate, switching submersible pumps, and adjusting the overflow weir height, ensuring the efficient and stable operation of the entire collaborative reuse system.

[0054] A second embodiment of the method for co-reusing domestic sewage and paddy field drainage according to an embodiment of this application includes the following steps:

[0055] S100. The water level of the farmland is measured in real time by the water level gauge in the farmland, and the farmland needs irrigation if it needs to be irrigated, based on the principle of water balance and the water requirements of crops at different growth stages. When the farmland needs irrigation, the current irrigation amount of the farmland is obtained.

[0056] S200: Obtain the sewage storage volume in the domestic sewage treatment pond, obtain the rainfall in the current farmland area in the next 3-5 days, and irrigate the farmland based on the sewage storage volume in the domestic sewage treatment pond, the rainfall in the current farmland area in the next 3-5 days, and the drainage volume of the paddy field drainage ditch.

[0057] In some specific embodiments, the step of measuring the water level of the farmland in real time using a water level gauge, and determining whether the farmland needs irrigation based on the principle of water balance and the water requirements of crops at different growth stages, and obtaining the current irrigation amount of the farmland when irrigation is needed, includes:

[0058] A preset water level threshold is set in the farmland. When the water level in the farmland is lower than the water level threshold, it is determined that the farmland needs irrigation, and the current irrigation amount of the farmland is obtained based on the area of ​​the farmland.

[0059] In some specific embodiments, the step of obtaining the sewage storage volume in the domestic sewage treatment pond, obtaining the rainfall forecast for the area where the farmland is located in the next 3-5 days, and irrigating the farmland based on the sewage storage volume in the domestic sewage treatment pond and the rainfall forecast for the area where the farmland is located in the next 3-5 days includes:

[0060] The sewage storage volume in the sewage treatment tank is obtained according to the water level gauge in the sewage treatment tank. The sewage in the sewage treatment tank is then transferred to the interior of the irrigation canal by a submersible pump in the sewage treatment tank, and then transferred to the interior of the farmland by a submersible pump on the irrigation canal.

[0061] In some specific embodiments, when obtaining the sewage storage volume in the domestic sewage treatment pond, obtaining the rainfall forecast for the area where the farmland is located in the next 3-5 days, and irrigating the farmland based on the sewage storage volume in the domestic sewage treatment pond and the rainfall forecast for the area where the farmland is located in the next 3-5 days, the method further includes:

[0062] When the sewage storage volume in the sewage treatment pond is greater than or equal to the current irrigation volume of the farmland, the domestic sewage in the sewage treatment pond is transferred to the farmland for irrigation.

[0063] When the sewage storage volume in the sewage treatment pond is less than the current irrigation volume of the farmland, the domestic sewage in the sewage treatment pond is transferred to the farmland, and it is determined whether the sum of the water volume in the water storage tank and the sewage storage volume in the sewage treatment pond meets the current irrigation volume of the farmland.

[0064] In some specific embodiments, when obtaining the sewage storage volume in the domestic sewage treatment pond, obtaining the rainfall forecast for the area where the farmland is located in the next 3-5 days, and irrigating the farmland based on the sewage storage volume in the domestic sewage treatment pond and the rainfall forecast for the area where the farmland is located in the next 3-5 days, the method further includes:

[0065] When the total amount of water in the water storage tank and the amount of sewage stored in the domestic sewage treatment pond meets the current irrigation demand of the farmland, the water in the water storage tank is transferred to the farmland for irrigation.

[0066] When the total amount of water in the water storage tank and the amount of sewage stored in the domestic sewage treatment pond is insufficient to meet the current irrigation needs of the farmland, the water in the water storage tank is transferred to the farmland, and the water in the pond is transferred to the water storage tank by the submersible pump, and then pumped into the farmland by the submersible pump inside the water storage tank for irrigation.

[0067] It should be understood that the core of the S100 step is to accurately determine whether farmland needs irrigation through "real-time monitoring + scientific models" and calculate the current required irrigation amount, providing data support for subsequent water supply. The specific process is as follows:

[0068] The basic principle of real-time monitoring of farmland water level: This step relies on the water level gauge 6 set in the middle of farmland 4. The water level gauge can collect water level data of the farmland soil surface and root zone in real time (such as the water level height corresponding to soil moisture content, the thickness of the water layer on the field surface, etc.) and transmit the data to the system control center in real time to ensure the authenticity and timeliness of the data. Compared with manual monitoring, the design of the water level gauge in the middle of the farmland can avoid misjudgment caused by the difference between the water level at the edge of the farmland and the water level in the center, and more accurately reflect the overall water status of the farmland.

[0069] The system assesses irrigation needs using a dual-dimensional approach: it doesn't rely solely on water level data, but integrates two core dimensions: the "water balance principle" and the "water requirement characteristics of crops at different growth stages."

[0070] Application of the water balance principle: The system calculates the farmland's "water income" (such as previous irrigation water and natural rainfall) and "water expenditure" (such as crop transpiration, soil infiltration, and surface runoff), and uses the difference between the two to determine the actual water surplus or deficit of the farmland. For example, if the farmland's transpiration is high at a certain time, even if the water level gauge data is not below the threshold, if the water balance calculation shows that a water deficit is about to occur, the system will predict the irrigation demand in advance to avoid crop drought.

[0071] Adapting to Crop Growth Stage Water Requirements: Different crops (such as rice and wheat) and different growth stages of the same crop (such as tillering, jointing, and grain-filling stages of rice) have vastly different water requirements. The system presets water requirement parameters for each growth stage of different crops (e.g., maintaining a water layer of 3-5 cm on the field surface during the rice tillering stage and 2-3 cm during the grain-filling stage), and adjusts the judgment criteria based on real-time water level gauge data. For example, rice has a high water requirement during the tillering stage, so the water level threshold is set to 3 cm; when the water level is below 3 cm, irrigation is deemed necessary. Conversely, water requirement decreases during the grain-filling stage, so the water level threshold is lowered to 2 cm to avoid over-irrigation leading to lodging or disease.

[0072] The precise calculation logic for irrigation volume: When the system determines that farmland needs irrigation based on the above two dimensions, it will further calculate the current irrigation volume. In a specific embodiment, the core calculation basis is "farmland area + water level difference": The system first obtains the actual planting area of ​​the farmland (preset in the system database), and then calculates the amount of water to be supplemented based on the difference between the suitable water level threshold for the current growth stage of the crop and the real-time water level, combined with parameters such as soil bulk density and porosity (the formula can be simplified to: Irrigation volume = farmland area × water level difference × soil effective water holding coefficient). For example, for a 1-acre (approximately 667㎡) paddy field, the suitable water level threshold during the tillering stage is 4cm, the real-time water level is 2cm, and the water level difference is 2cm (0.02m), then the basic irrigation volume is approximately 667㎡ × 0.02m = 13.34m. 3 Then, by combining this with fine-tuning the soil permeability coefficient, the precise irrigation amount is finally determined, avoiding the problems of "over-irrigation leading to waste and under-irrigation leading to insufficient irrigation".

[0073] Step S200, following the determination of irrigation demand and volume in S100, achieves efficient irrigation through "multi-source priority scheduling." Its core principle is to combine the volume of domestic sewage treatment ponds and rainfall data to sequentially utilize reclaimed water, recycled wastewater, and emergency water sources. The specific process is as follows:

[0074] Multi-source data acquisition and preprocessing:

[0075] Water volume acquisition for domestic sewage treatment pond: Relying on the water level gauge 6 installed inside the domestic sewage treatment pond 3, the system calculates the current sewage storage volume (storage volume = pond bottom area × water level height) by monitoring the water level height through the water level gauge and combining it with the preset volume parameters of the sewage treatment pond (such as pond length, pond width, and pond depth). At the same time, it ensures that the sewage has reached the farmland irrigation water quality standard (the pretreatment stage has been completed, and only the water volume needs to be confirmed here).

[0076] Rainfall data acquisition: The system can obtain real-time rainfall data for farmland areas in two ways: first, by connecting to the local meteorological department's real-time rainfall data interface to obtain the regional average rainfall; second, by setting up small rain gauges around the farmland to collect the actual rainfall in that area (more accurate). The core function of rainfall data is to determine whether natural precipitation can supplement some of the irrigation needs—if the current rainfall is large (e.g., 5mm of rainfall in 1 hour, and further rainfall is forecast), the system will appropriately reduce the irrigation amount to avoid redundant water supply.

[0077] Multi-source priority scheduling and irrigation execution: The system executes irrigation in four steps according to the principle of "reclaimed water priority, recycled drainage supplementation, and emergency water source backup" to ensure maximum water resource utilization.

[0078] Step 1: Priority supply of sewage from the domestic sewage treatment pond: When the sewage storage volume in the domestic sewage treatment pond is greater than or equal to the current irrigation volume of the farmland, the system controls the submersible pump 10 connected to the sewage treatment pond to start, transporting the treated sewage to the irrigation canal 1, and then controls the electric micro gates 5 on both sides of the irrigation canal corresponding to the farmland to open, and the sewage enters the farmland through the electric micro gates to complete the irrigation; during this process, the water level gauge 6 monitors the farmland water level in real time, and closes the electric micro gates and submersible pump after reaching the appropriate value.

[0079] Step 2: Draining water from the storage tank when sewage volume is insufficient: When the sewage storage volume in the domestic sewage treatment pond is less than the current irrigation volume of the farmland, the system first transports all the sewage in the sewage treatment pond to the farmland (basic water supply), and then calculates the water volume in the storage tank 13 through the water level gauge in the drainage ditch 8 (or the preset volume parameter of the storage tank 13) to determine whether "sewage storage volume + water volume in the storage tank" is greater than or equal to the irrigation volume: If it is satisfied, the submersible pump 10 connected to the storage tank in the drainage ditch is started to pump the excess drainage (reclaimed drainage) collected in the storage tank to the farmland to supplement the remaining irrigation volume; the water volume in the storage tank comes from the previous farmland drainage and belongs to "secondary recycled water", which further improves the water resource utilization rate.

[0080] Step 3: Emergency water from the pond when the dual regenerated water sources are insufficient: If the "sewage storage volume + water volume in the storage tank" is still less than the irrigation volume, the system determines that the regenerated water source is insufficient and immediately switches to the emergency water source - controlling the submersible pump 10 connected to the pond 7 to start (the submersible pump is powered by the solar power system 11 to ensure stable energy), pumping the natural water sources such as rainwater and surface runoff stored in the pond to the farmland to supplement the remaining irrigation volume and prevent the farmland from being affected by water shortage; at the same time, the water level gauge 6 in the pond will monitor the pond water volume in real time to avoid excessive water pumping that could cause the pond to dry up and affect the ecology.

[0081] Step 4: Dynamic Adjustment and Monitoring Throughout the Irrigation Process: During the entire irrigation process, the farmland water level gauge 6, the sewage treatment pond water level gauge, the water storage tank water level gauge, and the pond water level gauge all transmit data in real time. The system dynamically adjusts the submersible pump speed and the opening degree of the electric micro-gate based on the data. For example, if there is sudden rainfall during the irrigation process, and the system detects that the rainfall has reached the replenishment threshold, it will immediately reduce the submersible pump speed or close part of the electric micro-gate to reduce the irrigation water volume and achieve "dynamic adaptation".

[0082] Obviously, those skilled in the art can make various modifications and variations to this invention without departing from its spirit and scope. Therefore, if these modifications and variations fall within the scope of the claims of this invention and their equivalents, this invention also intends to include these modifications and variations.

Claims

1. A device for the co-reuse of domestic sewage and paddy field drainage, characterized in that, include: An irrigation canal is connected at one end to a water source and a domestic sewage treatment pond. Multiple electric micro-gates and water level gauges are installed on both sides of the irrigation canal corresponding to the farmland. The electric micro-gates are located at the head of the farmland and automatically start and stop to achieve automatic irrigation of the farmland. The water level gauges are located in the middle of the farmland and are used to measure the water level of the farmland in real time. A drainage ditch is provided on the side of the farmland away from the irrigation canal. The drainage ditch has multiple drainage outlets corresponding to the farmland. One end of each drainage outlet is connected to a pond. The drainage ditch is equipped with multiple adjustable-height overflow weirs. The drainage ditch is also equipped with multiple submersible pumps connected to the farmland. The submersible pumps are powered by a solar power system.

2. The device for co-reusing domestic sewage and paddy field drainage according to claim 1, characterized in that, The domestic sewage treatment pond is connected to the irrigation channel via the submersible pump.

3. The device for co-reusing domestic sewage and paddy field drainage according to claim 2, characterized in that, The water level gauge is installed inside the sewage treatment pond and the pond.

4. The device for co-reusing domestic sewage and paddy field drainage according to claim 3, characterized in that, The drainage ditch is provided with multiple adjustable height overflow weirs, and a water storage tank is formed between the multiple adjustable height overflow weirs. The top of the adjustable height overflow weir is provided with a V-shaped opening.

5. The device for co-reusing domestic sewage and paddy field drainage according to claim 4, characterized in that, The solar power system is electrically connected to the electric microgate, submersible pump, and water level gauge, respectively.

6. A method for the co-reuse of domestic sewage and paddy field drainage, characterized in that, The device for co-reusing domestic sewage and paddy field drainage as described in any one of claims 1 to 5 includes the following steps: The water level in the farmland is measured in real time by the water level gauge in the farmland. The water level is then combined with the water balance principle and the water requirements of crops at different growth stages to determine whether the farmland needs irrigation. When the farmland needs irrigation, the current irrigation amount of the farmland is obtained. The system obtains the sewage storage volume in the domestic sewage treatment pond, the rainfall forecast for the current farmland area in the next 3-5 days, and irrigates the farmland based on the sewage storage volume in the domestic sewage treatment pond, the rainfall forecast for the current farmland area in the next 3-5 days, and the drainage volume of the paddy field drainage ditch.

7. A method for the co-reuse of domestic sewage and paddy field drainage according to claim 6, characterized in that, The process of measuring the water level of the farmland in real time using a water level gauge, and determining whether the farmland needs irrigation based on the principle of water balance and the water requirements of crops at different growth stages, and obtaining the current irrigation amount when the farmland needs irrigation, includes: A preset water level threshold is set in the farmland. When the water level in the farmland is lower than the water level threshold, it is determined that the farmland needs irrigation, and the current irrigation amount of the farmland is obtained based on the area of ​​the farmland.

8. A method for the co-reuse of domestic sewage and paddy field drainage according to claim 7, characterized in that, The process of obtaining the sewage storage volume in the domestic sewage treatment pond, obtaining the rainfall forecast for the area where the farmland is located in the next 3-5 days, and irrigating the farmland based on the sewage storage volume in the domestic sewage treatment pond and the rainfall forecast for the area where the farmland is located in the next 3-5 days includes: The sewage storage volume in the sewage treatment tank is obtained according to the water level gauge in the sewage treatment tank. The sewage in the sewage treatment tank is then transferred to the interior of the irrigation canal by a submersible pump in the sewage treatment tank, and then transferred to the interior of the farmland by a submersible pump on the irrigation canal.

9. A method for the co-reuse of domestic sewage and paddy field drainage according to claim 8, characterized in that, When obtaining the sewage storage volume in the domestic sewage treatment pond, obtaining the rainfall forecast for the area where the farmland is located in the next 3-5 days, and irrigating the farmland based on the sewage storage volume in the domestic sewage treatment pond and the rainfall forecast for the area where the farmland is located in the next 3-5 days, the method further includes: When the sewage storage volume in the sewage treatment pond is greater than or equal to the current irrigation volume of the farmland, the domestic sewage in the sewage treatment pond is transferred to the farmland for irrigation. When the sewage storage volume in the sewage treatment pond is less than the current irrigation volume of the farmland, the domestic sewage in the sewage treatment pond is transferred to the farmland, and it is determined whether the sum of the water volume in the water storage tank and the sewage storage volume in the sewage treatment pond meets the current irrigation volume of the farmland.

10. A method for the co-reuse of domestic sewage and paddy field drainage according to claim 9, characterized in that, When obtaining the sewage storage volume in the domestic sewage treatment pond, obtaining the rainfall forecast for the area where the farmland is located in the next 3-5 days, and irrigating the farmland based on the sewage storage volume in the domestic sewage treatment pond and the rainfall forecast for the area where the farmland is located in the next 3-5 days, the method further includes: When the total amount of water in the water storage tank and the amount of sewage stored in the domestic sewage treatment pond meets the current irrigation demand of the farmland, the water in the water storage tank is transferred to the farmland for irrigation. When the total amount of water in the water storage tank and the amount of sewage stored in the domestic sewage treatment pond is insufficient to meet the current irrigation needs of the farmland, the water in the water storage tank is transferred to the farmland, and the water in the pond is transferred to the water storage tank by the submersible pump, and then pumped into the farmland by the submersible pump inside the water storage tank for irrigation.

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