Farmland tail water treatment system and method

Abstract

The invention relates to the technical field of farmland tail water treatment, in particular to a farmland tail water treatment system and method. The farmland tail water collecting equipment collects initial tail water of the farmland in the preset area; the soil humidity monitoring equipment collects the current soil humidity of the farmland in the preset area; when the current soil humidity is smaller than a preset soil humidity threshold value, the intelligent terminal equipment controls the initial tail water to flow into farmland tail water desalting equipment, desalting treatment is conducted on the initial tail water, desalted tail water is obtained, and farmland in a preset area is irrigated based on the desalted tail water; and when the current soil humidity is greater than or equal to a preset soil humidity threshold value, the intelligent terminal equipment controls the initial tail water to flow into the farmland tail water pollution control equipment, performs pollution control treatment on the initial tail water to obtain pollution-controlled tail water, and discharges the pollution-controlled tail water into a drainage ditch to reduce water pollution. A'salt reduction-pollution control 'synchronization and'water resource-nutrient' dual-recovery system is constructed, multiple treatment targets are achieved, and the comprehensive utilization efficiency of saline-alkali land resources is improved.

Description

Technical Field

[0001] This invention relates to the field of farmland wastewater treatment technology, specifically to farmland wastewater treatment systems and methods. Background Technology

[0002] To address the problem of saline wastewater treatment, technologies such as physical desalination, electroadsorption, electrodialysis, chemical precipitation, biological methods, and interfacial evaporation desalination have been successively applied. Each technology has its own advantages and disadvantages: physical desalination is simple to operate, interfacial evaporation desalination is green and low-energy, while electroadsorption and electrodialysis are energy-intensive, chemical precipitation is prone to secondary pollution, and biological desalination has limited effectiveness; none of these can achieve integrated "desalination + pollution control." Ecological ditch technology can synergistically intercept nitrogen and phosphorus through bottom sediment, plants, and microorganisms, but it cannot solve the problem of salt accumulation and cannot meet the needs of treating complex pollution in saline-alkali land tailwater.

[0003] Existing research largely focuses on single areas, lacking studies on the correlation between desalination and non-point source pollution control, as well as integrated design, making it difficult to address the complex characteristics of "high salinity + high nitrogen and phosphorus" in saline-alkali land tailwater. Current technologies cannot synergistically desalinate and control pollution, nor can they simultaneously address water resource and nutrient recovery, resulting in a prominent contradiction between resource waste and pollution control. Therefore, there is an urgent need to develop integrated technology systems to construct a simultaneous "salinity reduction-pollution control" and "water resource-nutrient" dual recovery system, achieving multiple governance objectives and improving the comprehensive utilization efficiency of saline-alkali land resources. Summary of the Invention

[0004] This invention provides a farmland wastewater treatment system and method to solve the problem of difficulty in constructing a system for simultaneous "salt reduction and pollution control" and dual "water resource and nutrient recovery", thereby achieving multiple treatment goals and improving the comprehensive utilization efficiency of saline-alkali land resources.

[0005] In a first aspect, the present invention provides a farmland wastewater treatment system, comprising farmland wastewater collection equipment, farmland wastewater desalination equipment, farmland wastewater pollution control equipment, soil moisture monitoring equipment, and a smart terminal device; wherein, the farmland wastewater collection equipment is connected to the farmland wastewater desalination equipment and the farmland wastewater pollution control equipment respectively; the farmland wastewater desalination equipment is connected to a preset area of ​​farmland; and the farmland wastewater pollution control equipment is connected to a preset area of ​​drainage ditches; the farmland wastewater desalination equipment, the farmland wastewater pollution control equipment, and the soil moisture monitoring equipment are all communicatively connected to the smart terminal device, wherein: the farmland wastewater collection equipment is used to collect the initial wastewater from the preset area of ​​farmland; the soil moisture monitoring device is used to monitor the wastewater in the smart terminal device. Under the control of the system, the current soil moisture of the farmland in the preset area is collected; the intelligent terminal device is used to control the initial tailwater in the farmland tailwater collection device to flow into the farmland tailwater desalination device when the current soil moisture is less than the preset soil moisture threshold, and to control the farmland tailwater desalination device to desalinate the initial tailwater to obtain desalinated tailwater, which is then used to irrigate the farmland in the preset area; the intelligent terminal device is also used to control the initial tailwater in the farmland tailwater collection device to flow into the farmland tailwater pollution control device when the current soil moisture is greater than or equal to the preset soil moisture threshold, and to control the farmland tailwater pollution control device to control the initial tailwater to obtain pollution-controlled tailwater, which is then discharged into the drainage ditch to reduce water pollution.

[0006] In one optional embodiment, the farmland wastewater collection device includes: a farmland wastewater discharge well, a salinity sensor, a nitrogen and phosphorus concentration sensor, a liquid level sensor, a pump, and a collection well; wherein: the farmland wastewater discharge well is connected to a submerged pipe at a preset depth corresponding to a preset area of ​​farmland, and collects the initial wastewater corresponding to the preset area of ​​farmland in a directional manner; the salinity sensor is installed on the farmland wastewater discharge well to detect the initial salinity of the initial wastewater and transmit the initial salinity to a smart terminal device; the nitrogen and phosphorus concentration sensor is installed on the farmland wastewater discharge well to detect the initial nitrogen and phosphorus concentration of the initial wastewater and transmit the initial nitrogen and phosphorus concentration to the smart terminal device; the liquid level sensor... A sensor, installed on the farmland tailwater discharge well, is used to detect the initial water level of the initial tailwater in the farmland tailwater discharge well and transmit the initial water level to the intelligent terminal device; a water pump is connected at one end to the farmland tailwater discharge well and at the other end to the collection well, and is also communicatively connected to the intelligent terminal device; the intelligent terminal device is used to control the pumping power of the water pump according to at least one of the initial water level, initial salinity, and initial nitrogen and phosphorus concentration; the water pump is used to pump the initial tailwater in the farmland tailwater discharge well to the collection well under the control of the intelligent terminal device; the collection well has one outlet connected to the farmland tailwater desalination equipment and the other outlet connected to the farmland tailwater pollution control equipment.

[0007] In one optional embodiment, the collection well includes a tailwater pretreatment device and an online water quality monitoring instrument; both the online water quality monitoring instrument and the tailwater pretreatment device are communicatively connected to a smart terminal device, wherein: the smart terminal device is used to control the tailwater pretreatment device to perform desalination pretreatment on the initial tailwater when the initial salinity is greater than a first preset salinity threshold, to obtain desalinated pretreated tailwater; the online water quality monitoring instrument is used to monitor the pretreated salinity corresponding to the desalinated pretreated tailwater online; the smart terminal device is used to monitor the pretreated salinity corresponding to the desalinated pretreated tailwater. When the amount is less than or equal to the first preset salinity threshold, the wastewater pretreatment equipment is controlled to stop desalination; and / or an intelligent terminal device is used to control the wastewater pretreatment equipment to perform pollution control pretreatment on the initial wastewater when the initial nitrogen and phosphorus concentration is greater than the first preset nitrogen and phosphorus concentration threshold, to obtain pollution control pretreated wastewater; an online water quality monitor is used to monitor the pretreated nitrogen and phosphorus concentration corresponding to the pollution control pretreated wastewater online; and an intelligent terminal device is used to control the wastewater pretreatment equipment to stop pollution control treatment when the pretreated nitrogen and phosphorus concentration is less than or equal to the first preset nitrogen and phosphorus concentration threshold.

[0008] In one optional embodiment, the wastewater pretreatment equipment includes a desalination pretreatment device and a pollution control pretreatment device. The inlet of the desalination pretreatment device is connected to the outlet of a water pump via a first control valve, and the inlet of the pollution control pretreatment device is connected to the outlet of the water pump via a second control valve. The desalination pretreatment device and the pollution control pretreatment device are connected via a third control valve. The first outlet of the desalination pretreatment device is connected to a farmland wastewater desalination device via a fourth control valve, and the second outlet of the desalination pretreatment device is connected to a farmland wastewater pollution control device via a fifth control valve. The first outlet of the pollution control pretreatment device is connected to the farmland wastewater desalination device via a sixth control valve. The second outlet of the equipment is connected to the farmland tailwater pollution control equipment via a seventh control valve. The first, second, third, fourth, fifth, sixth, and seventh control valves are all communicatively connected to a smart terminal device. The smart terminal device is used to control the first control valve to open when the initial salinity is greater than a first preset salinity threshold and the initial nitrogen and phosphorus concentration is less than or equal to the first preset nitrogen and phosphorus concentration threshold, so that the desalination pretreatment equipment can perform desalination pretreatment on the initial tailwater. It also controls the fourth or fifth control valve to open based on the current soil moisture. Alternatively, the smart terminal device is also used to control the opening of the fourth or fifth control valve when the initial salinity is low. When the initial salinity is equal to or greater than the first preset salinity threshold, and the initial nitrogen and phosphorus concentration is greater than the first preset nitrogen and phosphorus concentration threshold, the second control valve is opened to allow the pollution control pretreatment equipment to perform pollution control pretreatment on the initial effluent; and based on the current soil moisture, the sixth or seventh control valve is opened; or, the intelligent terminal device is further used to control the opening of the first control valve when the initial salinity is greater than the first preset salinity threshold, and the initial nitrogen and phosphorus concentration is greater than the first preset nitrogen and phosphorus concentration threshold, to allow the desalination pretreatment equipment to perform desalination pretreatment on the initial effluent; and to control the opening of the third control valve when the pretreated salinity of the desalination pretreated effluent is less than or equal to the first preset salinity threshold, to allow the pollution control pretreatment equipment to perform desalination pretreatment on the initial effluent. The wastewater pretreatment equipment performs pollution control pretreatment on the initial effluent; and controls the opening of the sixth or seventh control valve based on the current soil moisture; or, the intelligent terminal equipment is further used to control the opening of the second control valve when the initial salinity is greater than the first preset salinity threshold and the initial nitrogen and phosphorus concentration is greater than the first preset nitrogen and phosphorus concentration threshold, so that the pollution control pretreatment equipment performs pollution control pretreatment on the initial effluent; and to control the opening of the third control valve when the pretreatment nitrogen and phosphorus concentration corresponding to the pollution control pretreatment effluent is less than or equal to the first preset nitrogen and phosphorus concentration threshold, so that the desalination pretreatment equipment performs desalination pretreatment on the initial effluent; and to control the opening of the fourth or fifth control valve based on the current soil moisture.

[0009] In one optional embodiment, the farmland tailwater desalination equipment includes: a desalination zone, a bottom desalination device, an interfacial evaporation desalination device, a salt concentration monitoring device, and a light intensity sensor; wherein, the bottom desalination device is located at the bottom of the desalination zone, the interfacial evaporation desalination device is installed on a floating island in the desalination zone, the light intensity sensor is installed on the outer surface of the interfacial evaporation desalination device, and the salt concentration monitoring device is installed inside the desalination zone; wherein: the bottom of the desalination zone and the slopes communicating with the preset farmland area are covered with geomembranes to hold the initial tailwater flowing in from the farmland tailwater collection device; the bottom desalination device includes modified zeolite and natural zeolite as fillers. The system includes an ecological bag filter dam, a movable lifting support, and a control motor. The ecological bag filter dam is mounted on the movable lifting support, and the control motor is also mounted on the movable lifting support and communicates with the intelligent terminal device. A salt concentration monitoring device is used to monitor the current salt content at various locations and depths within the desalination zone. The intelligent terminal device controls the motor to move and lift the movable lifting support based on the current salt content at various locations and depths within the desalination zone, thereby enabling the ecological bag filter dam to desalinate the initial effluent at various locations and depths. An interface evaporation desalination device is used to desalinate the initial effluent.

[0010] In one optional embodiment, the outermost layer of the interfacial evaporation desalination device is a protective cover; the lower functional areas, from bottom to top, are: a bottom container, located at the very bottom of the entire interfacial evaporation desalination device, fixedly connected to the floating island of the desalination zone, in contact with the tailwater, and serving as the basic load-bearing structure for all components in the interfacial evaporation desalination device; zeolite, filled inside the bottom container; the upper functional areas, from bottom to top, are: polystyrene foam, with a middle water conveying area including black cotton thread; superhydrophilic filter paper, horizontally laid above the polystyrene foam; carbon nanotube powder, directly sprayed onto the upper surface of the superhydrophilic filter paper; the middle water transmission channel and salt collection area includes: black cotton thread, vertically penetrating the pre-reserved holes in the polystyrene foam, with the upper end embedded in the lower surface of the superhydrophilic filter paper and the lower end extending into the zeolite in the bottom container; and a salt collection plate, obliquely surrounding the outside of the superhydrophilic filter paper and carbon nanotube powder, located inside the protective cover and above the polystyrene foam.

[0011] In one optional embodiment, the farmland tailwater pollution control equipment includes: a nutrient absorption zone, the bottom layer of which is covered with a sediment substrate; the sediment substrate contains microorganisms; a plant community is planted on the sediment substrate; and the nutrient absorption zone is used to control pollution of the initial tailwater based on microorganisms and the plant community.

[0012] In one optional embodiment, the farmland tailwater pollution control equipment further includes a microbial activity monitoring module, an online nitrogen and phosphorus concentration monitor, a dissolved oxygen sensor, an intelligent aeration device, a slow-release fertilizer dosing device, and an underwater lighting device. The microbial activity monitoring module, the online nitrogen and phosphorus concentration monitor, the dissolved oxygen sensor, the intelligent aeration device, the slow-release fertilizer dosing device, and the underwater lighting device are all communicatively connected to an intelligent terminal device. Specifically: the microbial activity monitoring module is installed in the sediment substrate to monitor the current microbial activity value of the sediment substrate and transmit the current microbial activity value to the intelligent terminal device; the online nitrogen and phosphorus concentration monitor is installed in the nutrient absorption area to monitor the current nitrogen and phosphorus concentration of the initial tailwater in the nutrient absorption area and transmit the current nitrogen and phosphorus concentration to the intelligent terminal device; the dissolved oxygen sensor is installed in the nutrient absorption area to monitor the current dissolved oxygen concentration of the initial tailwater in the nutrient absorption area and transmit the current dissolved oxygen concentration to the intelligent terminal device; the intelligent terminal device… The system is used to calculate the nitrogen and phosphorus concentration reduction efficiency based on the current nitrogen and phosphorus concentration. The intelligent terminal device is also used to control an intelligent aeration device to aerate and increase the current dissolved oxygen concentration when the current microbial activity value is lower than a preset microbial activity threshold, the nitrogen and phosphorus concentration reduction efficiency is lower than a preset nitrogen and phosphorus concentration reduction efficiency threshold, and the current dissolved oxygen concentration is lower than a preset dissolved oxygen concentration threshold. The intelligent aeration device is installed on the bottom sediment substrate. The intelligent terminal device is also used to control a slow-release fertilizer application device to apply slow-release fertilizer and increase the current microbial activity value when the current microbial activity value is lower than a preset microbial activity threshold, the nitrogen and phosphorus concentration reduction efficiency is lower than a preset nitrogen and phosphorus concentration reduction efficiency threshold, but the current dissolved oxygen concentration is greater than or equal to a preset dissolved oxygen concentration threshold. The slow-release fertilizer application device is installed around the bottom sediment substrate. The intelligent terminal device is also used to control an underwater lighting device to provide supplemental lighting when the current nitrogen and phosphorus concentration is greater than a second preset nitrogen and phosphorus concentration threshold. The underwater lighting device is installed above the plant community.

[0013] In one optional embodiment, the farmland wastewater treatment system further includes a wind-solar hybrid power generation device, which is communicatively connected to the smart terminal device, and is also communicatively connected to the farmland wastewater collection device, the farmland wastewater desalination device, and the farmland wastewater pollution control device; wherein: the wind-solar hybrid power generation device is used to generate electricity and supply power to the smart terminal device and the various electrical devices in the farmland wastewater collection device, the farmland wastewater desalination device, and the farmland wastewater pollution control device.

[0014] In a second aspect, the present invention provides a method for treating farmland wastewater, applied to a farmland wastewater treatment system according to the first aspect or any corresponding embodiment thereof, the method comprising: Obtain the current soil moisture of farmland in the preset area; When the current soil moisture is less than the preset soil moisture threshold, the initial tailwater in the farmland tailwater collection device is controlled to flow into the farmland tailwater desalination device, and the farmland tailwater desalination device is controlled to desalinate the initial tailwater to obtain desalinated tailwater. The desalinated tailwater is then used to irrigate the preset area of ​​farmland. When the current soil moisture is greater than or equal to the preset soil moisture threshold, the initial tailwater in the farmland tailwater collection device is controlled to flow into the farmland tailwater pollution control device, and the farmland tailwater pollution control device is controlled to treat the initial tailwater to obtain pollution-controlled tailwater. The pollution-controlled tailwater is then discharged into the drainage ditch to reduce water pollution.

[0015] The farmland wastewater treatment system and method provided in this application embodiment can collect initial wastewater from farmland in a predetermined area, preventing wastewater from overflowing and seeping into the farmland. This reduces secondary pollution of soil and surrounding shallow groundwater by pollutants such as salt, nitrogen, and phosphorus at the source, laying the foundation for subsequent targeted treatment. The intelligent terminal device accurately determines the wastewater flow direction based on the current soil moisture. When the current soil moisture is less than a preset soil moisture threshold, the farmland is in a water-scarce state. The initial wastewater is controlled to enter the desalination equipment for treatment before being re-irrigated into the farmland, replenishing the farmland's moisture while preventing salt accumulation and soil salinization, thus improving the recycling rate of agricultural water resources. When the current soil moisture is greater than or equal to the preset soil moisture threshold, the farmland does not require irrigation. The initial wastewater is controlled to enter the pollution control equipment for treatment, reducing the concentration of pollutants such as nitrogen and phosphorus, and minimizing the impact of agricultural non-point source pollution on drainage ditches and downstream water bodies. Intelligent terminal equipment coordinates and controls the entire process of wastewater collection, diversion, and treatment. It dynamically adjusts treatment strategies based on soil moisture conditions without human intervention, significantly reducing manual maintenance costs. Simultaneously, the linkage between desalination, pollution control, and monitoring equipment ensures the stability and reliability of treatment results. This constructs a simultaneous "salinity reduction-pollution control" and "water resource-nutrient" dual recovery system, achieving multiple governance objectives and improving the comprehensive utilization efficiency of saline-alkali land resources. Attached Figure Description

[0016] 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.

[0017] Figure 1 This is a schematic diagram of the structure of a first type of farmland tailwater treatment system according to an embodiment of the present invention; Figure 2 This is a schematic diagram of the structure of a second type of farmland tailwater treatment system according to an embodiment of the present invention; Figure 3This is a schematic diagram of the structure of a water collection well in a farmland tailwater treatment system according to an embodiment of the present invention. Figure 4 This is a schematic diagram of the structure of a farmland tailwater desalination device in a farmland tailwater treatment system according to an embodiment of the present invention. Figure 5 This is a schematic diagram of the structure of a farmland tailwater pollution control device in a farmland tailwater treatment system according to an embodiment of the present invention. Figure 6 This is a schematic diagram of the structure of the third type of farmland tailwater treatment system according to an embodiment of the present invention; Figure 7 This is a schematic flowchart of the farmland tailwater treatment method according to an embodiment of the present invention. Detailed Implementation

[0018] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0019] It is understood that before using the technical solutions disclosed in the various embodiments of the present invention, users should be informed of the types, scope of use, and usage scenarios of the personal information involved in the present invention and their authorization should be obtained in accordance with relevant laws and regulations through appropriate means.

[0020] 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. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this invention, "a plurality of" means two or more, unless otherwise explicitly specified.

[0021] This invention provides a farmland wastewater treatment system, such as Figure 1 As shown, the farmland wastewater treatment system includes farmland wastewater collection equipment 1, farmland wastewater desalination equipment 2, farmland wastewater pollution control equipment 3, soil moisture monitoring equipment 4, and intelligent terminal equipment 5. The farmland wastewater collection equipment 1 is connected to both the farmland wastewater desalination equipment 2 and the farmland wastewater pollution control equipment 3. The farmland wastewater desalination equipment 2 is connected to a pre-defined area of ​​farmland, and the farmland wastewater pollution control equipment 3 is connected to a pre-defined area of ​​drainage ditches. The farmland wastewater desalination equipment 2, the farmland wastewater pollution control equipment 3, and the soil moisture monitoring equipment 4 are all communicatively connected to the intelligent terminal equipment 5. Farmland tailwater collection device 1 is used to collect the initial tailwater from farmland in a preset area; Soil moisture monitoring device 4 is used to collect the current soil moisture of farmland in a preset area under the control of intelligent terminal device 5; The intelligent terminal device 5 is used to control the initial tailwater in the farmland tailwater collection device 1 to flow into the farmland tailwater desalination device 2 when the current soil moisture is less than the preset soil moisture threshold, and to control the farmland tailwater desalination device 2 to desalinate the initial tailwater to obtain desalinated tailwater, and to irrigate the preset area of ​​farmland based on the desalinated tailwater. The intelligent terminal device 5 is also used to control the initial tailwater in the farmland tailwater collection device 1 to flow into the farmland tailwater pollution control device 3 when the current soil moisture is greater than or equal to the preset soil moisture threshold, and to control the farmland tailwater pollution control device 3 to treat the initial tailwater to obtain pollution-controlled tailwater, and to discharge the pollution-controlled tailwater into the drainage ditch to reduce water pollution.

[0022] Specifically, the core function of the farmland wastewater collection equipment 1 is to efficiently collect the initial wastewater from farmland in a pre-defined area, ensuring that no wastewater is missed or lost. Through pre-designed collection pipes or water collection facilities, the initial wastewater carrying pollutants such as salt, nitrogen, and phosphorus from the farmland is collected and stored, providing a stable water source for subsequent diversion and treatment, and avoiding secondary soil pollution or water waste caused by direct overflow of wastewater.

[0023] Under the unified control of the intelligent terminal device 5, the soil moisture monitoring device 4 periodically or in real time collects the current soil moisture data of farmland in a preset area. The monitoring points are evenly distributed in key areas of the farmland to ensure that the data can accurately reflect the overall soil moisture condition of the farmland. The collected soil moisture data is uploaded to the intelligent terminal device 5 in real time, serving as the core basis for determining whether the farmland needs irrigation.

[0024] After receiving the start command from the intelligent terminal device 5, the farmland wastewater desalination equipment 2 desalinates the initial wastewater transported by the farmland wastewater collection equipment 1. Through core processes such as physical adsorption and evaporation desalination, it removes sodium ions, chloride ions, and other salt ions from the initial wastewater, reducing the salt content of the treated desalinated wastewater to within the allowable range for farmland irrigation. After treatment, according to the instructions of the intelligent terminal device 5, the desalinated wastewater is transported to the farmland through irrigation pipelines.

[0025] The farmland effluent pollution control equipment 3 responds to control commands from the intelligent terminal device 5, receiving the initial effluent diverted from the farmland effluent collection device 1 and focusing on the removal of pollutants such as nitrogen and phosphorus. Through processes such as ecological absorption and microbial degradation, the concentration of pollutants such as ammonia nitrogen and total phosphorus in the effluent is reduced, preventing pollutants from being discharged into natural water bodies and causing non-point source pollution. After the treated effluent meets the discharge requirements, it is discharged into the pre-designated drainage ditch through pipelines.

[0026] As the core control unit of the system, the intelligent terminal device 5 receives real-time soil moisture data uploaded by the soil moisture monitoring device 4, as well as the operating status data of the farmland tailwater desalination device 2 and the pollution control device. It compares the current soil moisture with a preset soil moisture threshold to determine the farmland's irrigation needs. If the current soil moisture is lower than the preset threshold, indicating a water shortage in the farmland, the intelligent terminal device 5 controls the farmland tailwater collection device 1 to switch its flow path, allowing the initial tailwater to flow into the farmland tailwater desalination device 2. Simultaneously, it issues a desalination treatment command to the farmland tailwater desalination device 2. After treatment, it controls the farmland tailwater desalination device 2 to deliver the desalinated tailwater to the farmland for irrigation.

[0027] If the current soil moisture is greater than or equal to a preset soil moisture threshold, the farmland does not require irrigation. The intelligent terminal device 5 controls the farmland wastewater collection device 1 to switch the flow path, allowing the initial wastewater to flow into the farmland wastewater control device 3. Simultaneously, it issues a pollution control treatment command to the farmland wastewater control device 3. After the treatment meets the standards, the device controls the farmland wastewater control device 3 to discharge the wastewater into a drainage ditch. Furthermore, the intelligent terminal device 5 monitors the operating status of the farmland wastewater desalination device 2 and the farmland wastewater control device 3 throughout the process to ensure the normal progress of the treatment process. If any abnormality occurs in the equipment, a warning signal is issued promptly.

[0028] The farmland wastewater treatment system provided in this application embodiment includes a farmland wastewater collection device 1 that can directionally collect the initial wastewater from a preset area of ​​farmland, preventing wastewater from overflowing and leaking into the farmland. This reduces secondary pollution of the soil and surrounding shallow groundwater by pollutants such as salt, nitrogen, and phosphorus from the source, laying the foundation for subsequent targeted treatment. The intelligent terminal device 5 accurately determines the wastewater flow direction based on the current soil moisture. When the current soil moisture is less than a preset soil moisture threshold, the farmland is in a water-scarce state. The initial wastewater is controlled to enter the desalination equipment for treatment before being re-irrigated into the farmland, replenishing the farmland's moisture while preventing salt accumulation and soil salinization, thus improving the recycling rate of agricultural water resources. When the current soil moisture is greater than or equal to the preset soil moisture threshold, the farmland does not require irrigation. The initial wastewater is controlled to enter the pollution control equipment for treatment, reducing the concentration of pollutants such as nitrogen and phosphorus, and minimizing the impact of agricultural non-point source pollution on drainage ditches and downstream water bodies. The intelligent terminal equipment 5 coordinates and controls the entire process of wastewater collection, diversion, and treatment. It can dynamically adjust the treatment strategy according to the soil moisture of farmland without human intervention, which greatly reduces the cost of manual operation and maintenance. At the same time, the linkage between desalination, pollution control equipment and monitoring equipment ensures the stability and reliability of the treatment effect.

[0029] In one optional embodiment of this application, such as Figure 2As shown, the farmland wastewater collection device 1 includes: a farmland wastewater discharge well 11, a salinity sensor 12, a nitrogen and phosphorus concentration sensor 13, a liquid level sensor 14, a water pump 15, and a collection well 16; wherein: the farmland wastewater discharge well 11 is connected to a submerged pipe at a preset depth corresponding to a preset area of ​​farmland, and collects the initial wastewater corresponding to the preset area of ​​farmland in a directional manner; the salinity sensor 12 is installed on the farmland wastewater discharge well 11 to detect the initial salinity of the initial wastewater and transmit the initial salinity to the intelligent terminal device 5; the nitrogen and phosphorus concentration sensor 13 is installed on the farmland wastewater discharge well 11 to detect the initial nitrogen and phosphorus concentration of the initial wastewater and transmit the initial nitrogen and phosphorus concentration to the intelligent terminal device 5; the liquid level sensor 14... Installed on the farmland tailwater discharge well 11, it is used to detect the initial water level of the initial tailwater in the farmland tailwater discharge well 11 and transmit the initial water level to the intelligent terminal device 5; the pump 15 is connected to the farmland tailwater discharge well 11 at one end and to the collection well 16 at the other end, and is also connected to the intelligent terminal device 5; the intelligent terminal device 5 is used to control the pumping power of the pump 15 according to at least one of the initial water level, initial salinity, and initial nitrogen and phosphorus concentration; the pump 15 is used to pump the initial tailwater in the farmland tailwater discharge well 11 to the collection well 16 under the control of the intelligent terminal device 5; the collection well 16 has one outlet connected to the farmland tailwater desalination device 2 and the other outlet connected to the farmland tailwater pollution control device 3.

[0030] Specifically, after rainfall or irrigation, farmland in the designated area produces initial wastewater carrying pollutants such as salt, nitrogen, and phosphorus. A submerged pipe at a predetermined depth underground within the farmland acts as a guide, directing and collecting the dispersed initial wastewater. This predetermined depth can be 1.5 meters or 2 meters underground. The farmland wastewater discharge well 11 is directly connected to the submerged pipe. The collected initial wastewater flows along the pipe into the farmland wastewater discharge well 11, completing the centralized collection of the initial wastewater and preventing overflow and leakage that could cause secondary soil pollution or water waste.

[0031] After the initial wastewater flows into the discharge well, the salinity sensor 12, nitrogen and phosphorus concentration sensor 13, and level sensor 14 installed in the farmland wastewater discharge well 11 simultaneously start working. The salinity sensor 12 accurately detects the initial salinity of the initial wastewater, clarifying the degree of salt pollution. The nitrogen and phosphorus concentration sensor 13 detects the initial nitrogen and phosphorus concentrations of the initial wastewater, understanding the load of key pollutants. The level sensor 14 monitors the initial water level of the initial wastewater in the farmland wastewater discharge well 11, understanding the initial wastewater collection volume and storage status.

[0032] The three sensors will transmit the detected initial salinity, initial nitrogen and phosphorus concentration, and initial water level data to the intelligent terminal device 5 in real time, forming a complete "status profile" of the tailwater, providing accurate data support for subsequent pumping and regulation.

[0033] After receiving the initial salinity, initial nitrogen and phosphorus concentration, and initial water level data transmitted by the three major sensors, the intelligent terminal device 5 makes a logical judgment based on "at least one of the initial water level, initial salinity, and initial nitrogen and phosphorus concentration".

[0034] If the initial water level is used for regulation only: if the initial water level is higher than the preset upper limit, the discharge well will overflow and an instruction to increase the pumping power will be issued; if the initial water level is lower than the preset lower limit, the discharge well will not have enough water and an instruction to "reduce the pumping power" or "stop the machine" will be issued; if the initial water level is within a reasonable range, the rated pumping power will be maintained. If water quality data is used for regulation: if the initial salinity or initial nitrogen and phosphorus concentrations far exceed the load capacity of subsequent treatment equipment, an instruction to "reduce pumping power" should be issued to slow down the conveying speed; if the water quality indicators are within the normal range, pump water normally according to the power matched to the water level. The water pump 15 receives the control command from the intelligent terminal device 5, adjusts its own operating power, and accurately pumps the initial tailwater in the discharge well to the collection well 16, realizing the dynamic adaptation of "water quantity-water quality-treatment load".

[0035] The collection well 16 serves as a transfer hub for the tailwater, receiving the initial tailwater from the pump 15 and concentrating it to ensure no leakage or stagnation. Optionally, the collection well 16 features a dual-outlet design, establishing physical connections with both the farmland tailwater desalination equipment 2 and the farmland tailwater pollution control equipment 3. Subsequently, the intelligent terminal device 5 will combine soil moisture data and tailwater status records to further determine the tailwater's destination, controlling the opening of the corresponding outlet of the collection well 16 to direct the initial tailwater towards the desalination or pollution control equipment, laying the foundation for either "desalination reuse" or "pollution control discharge" processes.

[0036] The farmland tailwater treatment system provided in this application embodiment connects the farmland tailwater discharge well 11 to a submerged pipe at a preset depth. This allows for the directional collection of initial farmland tailwater, preventing secondary soil salinization caused by overflow and leakage. It also prevents pollutants such as nitrogen and phosphorus from directly infiltrating shallow groundwater, thus laying a solid foundation for source control in subsequent treatment. Three sensors—salt content, nitrogen and phosphorus concentration, and liquid level—simultaneously monitor key indicators of the tailwater, transmitting initial salinity, initial nitrogen and phosphorus concentration, and initial water level data to the intelligent terminal device 5 in real time, forming a "status profile" of the initial tailwater. This allows subsequent desalination and pollution control equipment to predict the treatment load in advance and provides precise basis for adjusting treatment process parameters, avoiding inefficiency caused by blind treatment. Based on at least one of the monitored data, the intelligent terminal device 5 precisely controls the power of the pump 15: increasing power to prevent overflow when the water level is too high, reducing power to prevent idling when the water level is too low, and reducing power when the water quality exceeds standards, allowing sufficient reaction time for subsequent treatment units. This control method not only ensures the stability of wastewater collection, but also achieves dynamic matching of "collection efficiency - treatment load", reducing equipment energy consumption and operation and maintenance costs.

[0037] In one alternative implementation, such as Figure 3 As shown, the collection well 16 includes a tailwater pretreatment device 161 and a water quality online monitoring instrument 162. Both the water quality online monitoring instrument 162 and the tailwater pretreatment device 161 are communicatively connected to the intelligent terminal device 5. Specifically: the intelligent terminal device 5 controls the tailwater pretreatment device 161 to perform desalination pretreatment on the initial tailwater when the initial salinity is greater than a first preset salinity threshold, obtaining desalinated pretreated tailwater; the water quality online monitoring instrument 162 is used to monitor the pretreated salinity corresponding to the desalinated pretreated tailwater online; the intelligent terminal device 5 is used to monitor the pretreated salinity corresponding to the desalinated pretreated tailwater. When the initial nitrogen and phosphorus concentration is less than or equal to the first preset salinity threshold, the wastewater pretreatment equipment 161 is controlled to stop desalination; and / or; the intelligent terminal device 5 is used to control the wastewater pretreatment equipment 161 to perform pollution control pretreatment on the initial wastewater when the initial nitrogen and phosphorus concentration is greater than the first preset nitrogen and phosphorus concentration threshold, to obtain pollution control pretreated wastewater; the online water quality monitor 162 is used to monitor the pretreated nitrogen and phosphorus concentration corresponding to the pollution control pretreated wastewater online; the intelligent terminal device 5 is used to control the wastewater pretreatment equipment 161 to stop pollution control treatment when the pretreated nitrogen and phosphorus concentration is less than or equal to the first preset nitrogen and phosphorus concentration threshold.

[0038] In one optional embodiment, the wastewater pretreatment equipment 161 includes a desalination pretreatment equipment 1611 and a pollution control pretreatment equipment 1612. The inlet of the desalination pretreatment equipment 1611 is connected to the outlet of the pump 15 via a first control valve 1613, and the inlet of the pollution control pretreatment equipment 1612 is connected to the outlet of the pump 15 via a second control valve 1614. The desalination pretreatment equipment 1611 and the pollution control pretreatment equipment 1612 are connected via a third control valve 1615. The first outlet of the desalination pretreatment equipment 1611 is connected to the farmland wastewater desalination equipment 2 via a fourth control valve 1616. The second outlet of 611 is connected to the farmland tailwater pollution control equipment 3 via the fifth control valve 1617; the first outlet of the pollution control pretreatment equipment 1612 is connected to the farmland tailwater desalination equipment 2 via the sixth control valve 1618, and the second outlet of the pollution control pretreatment equipment 1612 is connected to the farmland tailwater pollution control equipment 3 via the seventh control valve 1619; wherein, the first control valve 1613, the second control valve 1614, the third control valve 1615, the fourth control valve 1616, the fifth control valve 1617, the sixth control valve 1618, and the seventh control valve 1619 are all communicatively connected to the intelligent terminal equipment 5; wherein: The intelligent terminal device 5 is configured to: control the opening of the first control valve 1613 when the initial salinity is greater than a first preset salinity threshold and the initial nitrogen and phosphorus concentration is less than or equal to a first preset nitrogen and phosphorus concentration threshold, so that the desalination pretreatment equipment 1611 performs desalination pretreatment on the initial effluent; and control the opening of the fourth control valve 1616 or the fifth control valve 1617 based on the current soil moisture; or, the intelligent terminal device 5 is further configured to: control the opening of the second control valve 1614 when the initial salinity is less than or equal to the first preset salinity threshold and the initial nitrogen and phosphorus concentration is greater than a first preset nitrogen and phosphorus concentration threshold, so that the pollution control pretreatment equipment 1612 performs pollution control pretreatment on the initial effluent; and control the opening of the sixth control valve 1618 or the seventh control valve 1619 based on the current soil moisture; or, the intelligent terminal device 5 is further configured to: control the opening of the first control valve 1613 when the initial salinity is greater than the first preset salinity threshold and the initial nitrogen and phosphorus concentration is greater than a first preset nitrogen and phosphorus concentration threshold, so that the desalination pretreatment equipment 1611 performs desalination pretreatment on the initial effluent. The treatment equipment 1611 performs desalination pretreatment on the initial effluent; when the pretreated salinity of the desalination pretreated effluent is less than or equal to a first preset salinity threshold, the third control valve 1615 is opened to allow the pollution control pretreatment equipment 1612 to perform pollution control pretreatment on the initial effluent; and based on the current soil moisture, the sixth control valve 1618 or the seventh control valve 1619 is opened; or, the intelligent terminal equipment 5 is further used to control the second control valve 1614 to open when the initial salinity is greater than the first preset salinity threshold and the initial nitrogen and phosphorus concentration is greater than the first preset nitrogen and phosphorus concentration threshold, so that the pollution control pretreatment equipment 1612 performs pollution control pretreatment on the initial effluent; when the pretreated nitrogen and phosphorus concentration of the pollution control pretreated effluent is less than or equal to the first preset nitrogen and phosphorus concentration threshold, the third control valve 1615 is opened to allow the desalination pretreatment equipment 1611 to perform desalination pretreatment on the initial effluent; and based on the current soil moisture, the fourth control valve 1616 or the fifth control valve 1617 is opened.

[0039] Specifically, the intelligent terminal device 5 can compare the initial salinity with a first preset salinity threshold and the initial nitrogen and phosphorus concentration with a first preset nitrogen and phosphorus concentration threshold. In one scenario, if the initial salinity is greater than the first preset salinity threshold and the initial nitrogen and phosphorus concentration is less than or equal to the first preset nitrogen and phosphorus concentration threshold, the intelligent terminal device 5 controls the first control valve 1613 to open while simultaneously closing all other control valves, allowing the initial effluent to flow into the desalination pretreatment equipment 1611. The desalination pretreatment equipment 1611 starts and desalinates the initial effluent, for example, through zeolite adsorption or evaporation. The online water quality monitor 162 monitors the pretreated salinity of the desalination pretreatment effluent in real time and continuously feeds data back to the intelligent terminal device 5. When the pretreated salinity is detected to be less than or equal to the first preset salinity threshold, the intelligent terminal device 5 controls the desalination pretreatment equipment 1611 to stop operating.

[0040] The intelligent terminal device 5 calls up soil moisture monitoring data. If the current soil moisture is less than the preset soil moisture threshold, the farmland is short of water and needs irrigation. The fourth control valve 1616 is opened to transport the desalinated tailwater to the farmland tailwater desalination equipment 2 for deep treatment and reuse. If the current soil moisture is greater than or equal to the preset soil moisture threshold, the farmland is not short of water and does not need irrigation. The fifth control valve 1617 is opened to transport the desalinated tailwater to the farmland tailwater pollution control equipment 3. The farmland tailwater pollution control equipment 3 then performs simple pollution control on the desalinated tailwater or discharges it directly.

[0041] In another scenario, if the initial salinity is less than or equal to a first preset salinity threshold, and the initial nitrogen and phosphorus concentration is greater than a first preset nitrogen and phosphorus concentration threshold, the intelligent terminal device 5 controls the second control valve 1614 to open, while simultaneously closing all other control valves, allowing the initial effluent to flow into the pollution control pretreatment device 1612. The pollution control pretreatment device 1612 starts and performs pollution control treatment on the initial effluent, for example, through microbial degradation or plant root adsorption. The online water quality monitor 162 monitors the pretreated nitrogen and phosphorus concentration of the pollution control pretreatment effluent in real time and continuously feeds data back to the intelligent terminal device 5. When the pretreated nitrogen and phosphorus concentration is detected to be less than the first preset nitrogen and phosphorus concentration threshold, the intelligent terminal device 5 controls the pollution control pretreatment device 1612 to stop operating. Then, the intelligent terminal device 5 calls the soil moisture monitoring data. If the current soil moisture is less than the preset soil moisture threshold, the farmland is short of water and needs irrigation. The sixth control valve 1618 is opened to transport the treated wastewater to the farmland wastewater desalination equipment 2. The farmland wastewater desalination equipment 2 then desalinates the treated wastewater before reuse. If the current soil moisture is greater than or equal to the preset soil moisture threshold, the farmland is not short of water and does not need irrigation. The seventh control valve 1619 is opened to transport the treated wastewater to the farmland wastewater pollution control equipment 3 for deep treatment before discharge.

[0042] In another scenario, if the initial salinity is greater than a first preset salinity threshold and the initial nitrogen and phosphorus concentrations are also greater than a first preset nitrogen and phosphorus concentration threshold, the intelligent terminal device 5 controls the first control valve 1613 to open while simultaneously closing all other control valves, allowing the initial effluent to flow into the desalination pretreatment equipment 1611. The desalination pretreatment equipment 1611 then starts, desalinating the initial effluent, for example, through zeolite adsorption or evaporation. The online water quality monitor 162 monitors the pretreated salinity of the desalination pretreatment effluent in real time and continuously feeds data back to the intelligent terminal device 5. When the pretreated salinity is detected to be less than or equal to the first preset salinity threshold, the intelligent terminal device 5 controls the desalination pretreatment equipment 1611 to stop operating.

[0043] After desalination, the treated effluent flows into the pollution control pretreatment equipment 1612 through the third control valve 1615, initiating pollution control treatment. The online water quality monitor 162 monitors the pretreated nitrogen and phosphorus concentrations of the pollution control pretreatment effluent in real time and continuously feeds data back to the intelligent terminal device 5. When the pretreated nitrogen and phosphorus concentration is detected to be lower than the first preset nitrogen and phosphorus concentration threshold, the intelligent terminal device 5 controls the pollution control pretreatment equipment 1612 to stop working.

[0044] The intelligent terminal device 5 calls up soil moisture monitoring data. If the current soil moisture is less than the preset soil moisture threshold, the farmland is short of water and needs irrigation. The device controls the sixth control valve 1618 to open, and transports the treated wastewater to the farmland wastewater desalination equipment 2. The farmland wastewater desalination equipment 2 then desalinates the treated wastewater before reuse. If the current soil moisture is greater than or equal to the preset soil moisture threshold, the farmland is not short of water and does not need irrigation. The device controls the seventh control valve 1619 to open, and transports the treated wastewater to the farmland wastewater pollution control equipment 3 for deep treatment before discharge.

[0045] In another scenario, if the initial salinity exceeds a first preset salinity threshold, the intelligent terminal device 5 controls the second control valve 1614 to open while simultaneously closing all other control valves, allowing the initial effluent to flow into the pollution control pretreatment equipment 1612. When the initial nitrogen and phosphorus concentration exceeds a first preset nitrogen and phosphorus concentration threshold, the treatment equipment 1612 activates to treat the initial effluent for pollution control, such as through microbial degradation or plant root adsorption. The online water quality monitor 162 monitors the pretreated nitrogen and phosphorus concentration of the pollution control pretreatment effluent in real time and continuously feeds data back to the intelligent terminal device 5. When the pretreated nitrogen and phosphorus concentration is detected to be below the first preset nitrogen and phosphorus concentration threshold, the intelligent terminal device 5 controls the pollution control pretreatment equipment 1612 to stop operating.

[0046] Then, the intelligent terminal device 5 controls the opening of the third control valve 1615 and the closing of the second control valve 1614. The treated effluent, after meeting pollution control standards, flows into the desalination pretreatment equipment 1611 through the third control valve 1615, initiating desalination treatment. The online water quality monitoring instrument 162 monitors the pre-treated salinity of the desalination pretreatment effluent in real time and continuously feeds data back to the intelligent terminal device 5. When the pre-treated salinity is detected to be less than or equal to the first preset salinity threshold, the intelligent terminal device 5 controls the desalination pretreatment equipment 1611 to stop working.

[0047] The intelligent terminal device 5 calls up soil moisture monitoring data. If the current soil moisture is less than the preset soil moisture threshold, the farmland is short of water and needs irrigation. The fourth control valve 1616 is opened to transport the desalinated tailwater to the farmland tailwater desalination equipment 2 for deep treatment and reuse. If the current soil moisture is greater than or equal to the preset soil moisture threshold, the farmland is not short of water and does not need irrigation. The fifth control valve 1617 is opened to transport the desalinated tailwater to the farmland tailwater pollution control equipment 3. The farmland tailwater pollution control equipment 3 then performs simple pollution control on the desalinated tailwater or discharges it directly.

[0048] The farmland wastewater treatment system provided in this application embodiment initiates desalination or pollution control pretreatment based on a comparison of the initial salinity with a first preset salinity threshold and the initial nitrogen and phosphorus concentrations with the first preset nitrogen and phosphorus concentration thresholds. Desalination pretreatment is initiated when salinity exceeds the standard, and pollution control pretreatment is initiated when nitrogen and phosphorus exceed the standard, prioritizing the treatment of exceeding indicators. This pretreatment method significantly reduces the impact of high-concentration pollutants on subsequent advanced treatment equipment, avoids overloading of treatment units, and extends equipment lifespan. The online water quality monitor 162 monitors the salinity or nitrogen and phosphorus concentrations of the pretreated wastewater in real time throughout the process, and the intelligent terminal device 5 automatically controls the start and stop of the pretreatment equipment based on the monitoring data. Treatment stops as soon as standards are met, without ineffective treatment. This closed-loop control mode ensures stable pretreatment results, avoids waste of energy and reagents, and improves the economic efficiency of the treatment process. By leveraging the coordinated operation of multiple control valves, the farmland wastewater treatment system can intelligently switch between four operating modes based on water quality indicators and soil moisture data: desalination only, pollution control only, desalination followed by pollution control, and pollution control followed by desalination. The treated wastewater is then directed to either desalination or pollution control equipment. This design adapts to wastewater with varying pollution loads and precisely addresses subsequent reuse or discharge needs, enhancing the flexibility and adaptability of the entire system.

[0049] In one alternative implementation, such as Figure 4As shown, the farmland tailwater desalination equipment 2 includes: a desalination zone 21, a bottom desalination device 22, an interface evaporation desalination device 23, a salt concentration monitoring device 24, and a light intensity sensor 25; wherein, the bottom desalination device 22 is set at the bottom of the desalination zone 21, the interface evaporation desalination device 23 is installed on the floating island of the desalination zone 21, the light intensity sensor 25 is installed on the outer surface of the interface evaporation desalination device 23, and the salt concentration monitoring device 24 is installed inside the desalination zone 21; wherein: the bottom of the desalination zone 21 and the slope connecting to the preset farmland area are covered with a geomembrane to hold the initial tailwater flowing in from the farmland tailwater collection device 1; the bottom desalination device 22 includes modified zeolite and natural zeolite The ecological bag filter dam, which serves as the filling material, is mounted on the movable lifting support, and the control motor is connected to the intelligent terminal device 5. A salt concentration monitoring device 24 monitors the current salt content at various locations and depths within the desalination zone 21. The intelligent terminal device 5 controls the control motor to move and lift the movable lifting support based on the current salt content at various locations and depths within the desalination zone 21, thereby enabling the ecological bag filter dam to desalinate the initial effluent at various locations and depths. An interface evaporation desalination device 23 is used to desalinate the initial effluent.

[0050] In one optional embodiment, the outermost layer of the interface evaporation desalination device 23 is a protective cover; the lower functional areas, from bottom to top, are: a bottom container, located at the bottom of the entire interface evaporation desalination device 23, fixedly connected to the floating island of the desalination zone 21, in contact with the tailwater, and serving as the basic load-bearing structure for all components in the interface evaporation desalination device 23; zeolite, filled inside the bottom container; the upper functional areas, from bottom to top, are: polystyrene foam, with a middle water conveying area including black cotton thread; superhydrophilic filter paper, horizontally laid above the polystyrene foam; carbon nanotube powder, directly sprayed onto the upper surface of the superhydrophilic filter paper; the middle water transmission channel and salt collection area includes: black cotton thread, vertically penetrating the reserved holes in the polystyrene foam, with the upper end embedded in the lower surface of the superhydrophilic filter paper and the lower end extending into the zeolite in the bottom container; and a salt collection plate, obliquely surrounding the outside of the superhydrophilic filter paper and carbon nanotube powder, located inside the protective cover and above the polystyrene foam.

[0051] Specifically, geomembranes have been pre-laid at the bottom of the desalination zone 21 and on the slopes connecting to the pre-designated farmland area to form a sealed tailwater containment space, preventing water leakage during the desalination process and secondary soil salinization. The tailwater, pretreated by the collection well 16 or directly transported, flows into the desalination zone 21 through pipelines, completing the water collection before desalination and preparing for the subsequent dual desalination process.

[0052] The core components of the bottom-layer desalination equipment 22, such as the ecological bag filter dam, movable lifting support, and control motor, are ready. The ecological bag filter dam is filled with a mixture of modified zeolite and natural zeolite, which has a strong salt ion adsorption capacity. The filler layer adopts a "layered filling" process. The upper layer is laid with 100mm thick modified zeolite, which is responsible for the efficient adsorption of salt ions. The lower layer is laid with 100mm thick natural zeolite, which is responsible for intercepting suspended impurities and protecting the upper modified zeolite layer, forming a composite functional layer of "adsorption + filtration" and extending the service life of the filler.

[0053] The salt concentration monitoring device 24 is activated, monitoring the current salt content at various horizontal and vertical depths in the desalination zone 21 in real time. The data is transmitted to the intelligent terminal device 5 in real time, forming a three-dimensional salt content distribution map. The intelligent terminal device 5 analyzes the three-dimensional data, comparing the current salt content at each point with a second preset salt content threshold. Based on the comparison results, it locates areas with high salt content, such as the key desalination zone 21, and issues movement and lifting commands to the control motor. The control motor drives the movable lifting bracket, moving the ecological bag filter dam to the key desalination zone 21. At the same time, the lifting height of the bracket is adjusted according to the depth of the tailwater in this area, ensuring that the filter dam is fully immersed in the water and in full contact with the tailwater at different depths.

[0054] When the tailwater flows through the ecological bag filter dam, the mixed zeolite packing retains salt ions through physical adsorption, completing the first stage of desalination. During the process, the salt concentration monitoring device 24 continuously provides data, and the intelligent terminal device 5 dynamically adjusts the position and height of the support to ensure that the tailwater in the entire desalination zone 21 can be treated efficiently.

[0055] The interface evaporation desalination device 23 is installed on the floating island of the desalination zone 21. A protective cover provides protection for the device without affecting light penetration. The bottom container directly contacts the tailwater of the desalination zone 21, completing the water reception. Zeolite in the bottom container first performs preliminary adsorption and desalination of the contacting tailwater, while simultaneously fixing the lower end of a black cotton thread. The black cotton thread, through capillary action, vertically transports the tailwater from the bottom container upwards, passing through pre-reserved holes in the polystyrene foam, and then embeds its upper end into the lower surface of the superhydrophilic filter paper. The tailwater spreads evenly on the filter paper surface, thus achieving a water diffusion layer effect. A light intensity sensor 25 monitors the ambient light conditions in real time, transmitting the data to the intelligent terminal device 5. The terminal adapts the operating status of the interface evaporation desalination device 23 according to the light intensity. Carbon nanotube powder is sprayed onto the surface of the superhydrophilic filter paper, absorbing solar energy and converting it into heat energy. This rapidly heats the tailwater on the filter paper surface, causing the water to evaporate as water vapor. Salt ions, unable to migrate with the water vapor, remain on the filter paper surface. The salt crystals produced by evaporation gradually fall off and are caught by the inclined salt collection plate surrounding the outside, preventing the salt particles from falling back into the tailwater, thus completing the second stage of desalination.

[0056] The bottom-level desalination device 22 and the interface evaporation desalination device 23 operate synchronously, forming a dual desalination system of "physical adsorption + photothermal evaporation," significantly improving desalination efficiency. The salt concentration monitoring device 24 continuously monitors the current salinity of the effluent from the desalination zone 21 and provides real-time feedback to the intelligent terminal device 5. When the salinity of the effluent across the entire desalination zone 21 drops to the preset irrigation standard, the intelligent terminal device 5 issues stop commands to both the bottom-level desalination device 22 and the interface evaporation desalination device 23, ending the desalination process. If the salinity in some areas still does not meet the standard, the intelligent terminal device 5 adjusts the position / height of the bottom-level filter dam or optimizes the operation of the interface evaporation desalination device 23 based on light intensity, such as extending the operating time, until the effluent fully meets the standard. The desalinated effluent is then exported by the intelligent terminal device 5 based on soil moisture data: if the farmland requires irrigation, it is transported to the preset farmland area via pipeline; if irrigation is not currently needed, it is temporarily stored in the desalination zone 21 or transported to a designated water storage facility for later use, achieving water resource recycling.

[0057] The farmland wastewater treatment system provided in this application embodiment uses a bottom-level desalination device 22 to adsorb salt ions through zeolite packing material in an ecological bag filter dam, and an interface evaporation desalination device 23 to separate salts using "capillary water transport + photothermal evaporation," forming a dual desalination mode of "physical adsorption + photothermal evaporation." Compared with a single desalination process, the salt removal rate is significantly improved, and the treated wastewater can directly meet farmland irrigation standards. Intelligent dynamic adaptation achieves uniform desalination across the entire area. A salt concentration monitoring device 24 collects real-time salt content data at various locations and depths in the desalination zone 21. Based on this data, an intelligent terminal device 5 controls a movable lifting support to precisely move and lift the ecological bag filter dam, targeting high-salinity areas and avoiding incomplete local desalination, ensuring that the salt content of the wastewater in the entire desalination zone 21 meets the standards. Driven by clean energy, reducing operating costs and environmental impact, the interface evaporation desalination equipment 23 uses solar energy as its core power source and achieves evaporation desalination through efficient photothermal conversion of carbon nanotube powder, without the need for additional electricity or chemical agents. At the same time, the bottom filter dam uses modified zeolite and natural zeolite fillers, which are green, environmentally friendly and recyclable, significantly reducing the operating costs and secondary pollution risks of the equipment.

[0058] In one alternative implementation, such as Figure 5 As shown, the farmland tailwater pollution control equipment 3 includes: a nutrient absorption zone 31, the bottom layer of which is covered with a bottom sediment substrate 32; the bottom sediment substrate 32 contains microorganisms; a plant community 33 is planted on the bottom sediment substrate 32; the nutrient absorption zone 31 is used to control pollution of the initial tailwater based on microorganisms and the plant community 33.

[0059] In one optional embodiment, the farmland tailwater pollution control equipment 3 further includes a microbial activity monitoring module 34, an online nitrogen and phosphorus concentration monitor 35, a dissolved oxygen sensor 36, an intelligent aeration device 37, a slow-release fertilizer dosing device 38, and an underwater lighting device 39. The microbial activity monitoring module 34, the online nitrogen and phosphorus concentration monitor 35, the dissolved oxygen sensor 36, the intelligent aeration device 37, the slow-release fertilizer dosing device 38, and the underwater lighting device 39 are all communicatively connected to the intelligent terminal device 5. The microbial activity monitoring module 34... 4. An online nitrogen and phosphorus concentration monitor 35, installed in the sediment substrate 32, is used to monitor the current microbial activity value of the sediment substrate 32 and transmit the current microbial activity value to the intelligent terminal device 5; 5. An online nitrogen and phosphorus concentration monitor 35, installed in the nutrient absorption area 31, is used to monitor the current nitrogen and phosphorus concentration of the initial effluent in the nutrient absorption area 31 and transmit the current nitrogen and phosphorus concentration to the intelligent terminal device 5; 6. A dissolved oxygen sensor 36, installed in the nutrient absorption area 31, is used to monitor the current dissolved oxygen concentration of the initial effluent in the nutrient absorption area 31 and transmit the current dissolved oxygen concentration to the intelligent terminal device 5. The system includes a terminal device 5; an intelligent terminal device 5 for calculating the nitrogen and phosphorus concentration reduction efficiency based on the current nitrogen and phosphorus concentration; the intelligent terminal device 5 is also used to control an intelligent aeration device 37 to aerate and increase the current dissolved oxygen concentration when the current microbial activity value is lower than a preset microbial activity threshold, the nitrogen and phosphorus concentration reduction efficiency is lower than a preset nitrogen and phosphorus concentration reduction efficiency threshold, and the current dissolved oxygen concentration is lower than a preset dissolved oxygen concentration threshold; wherein, the intelligent aeration device 37 is installed on the bottom sediment substrate 32; the intelligent terminal device 5 is also used to control a slow-release fertilizer application device 38 to apply slow-release fertilizer and increase the current microbial activity value when the current microbial activity value is lower than a preset microbial activity threshold, the nitrogen and phosphorus concentration reduction efficiency is lower than a preset nitrogen and phosphorus concentration reduction efficiency threshold, but the current dissolved oxygen concentration is greater than or equal to a preset dissolved oxygen concentration threshold; wherein, the slow-release fertilizer application device 38 is installed around the bottom sediment substrate 32; the intelligent terminal device 5 is also used to control an underwater lighting supplement device 39 to provide supplemental lighting when the current nitrogen and phosphorus concentration is greater than a second preset nitrogen and phosphorus concentration threshold; the underwater lighting supplement device 39 is installed above the plant community 33.

[0060] Specifically, the bottom layer of the nutrient absorption zone 31 is pre-laid with a sediment substrate 32 rich in microorganisms, and planted with plant communities 33 such as reeds and calamus that have strong nitrogen and phosphorus adsorption capabilities, forming a three-in-one ecological purification system of "microorganisms-plants-sediment". The initial effluent, which has been pretreated by the collection well 16 or directly transported, flows into the nutrient absorption zone 31 through pipelines. The effluent flows slowly in the zone, allowing sufficient reaction time for subsequent ecological purification.

[0061] As the effluent flows through the sediment substrate 32, microorganisms such as nitrifying bacteria, denitrifying bacteria, and polyphosphate-accumulating bacteria in the substrate metabolize and release ammonia nitrogen from the water, and convert soluble phosphorus into insoluble phosphorus, fixing it in the microbial cells or sediment. The roots of the plant community 33 actively absorb nitrogen and phosphorus nutrients from the effluent, converting them into biomass needed for their own growth. Simultaneously, root exudates provide a suitable growth environment for microorganisms, enhancing the synergistic purification effect of "microorganism-plant." Some nitrogen and phosphorus pollutants are deposited in the sediment through physical sedimentation, being adsorbed and fixed by sediment particles, completing basic pollution control at the ecological level.

[0062] The microbial activity monitoring module 34, the online nitrogen and phosphorus concentration monitor 35, and the dissolved oxygen sensor 36 are activated simultaneously to continuously collect core data. The microbial activity monitoring module 34 is embedded in the sediment substrate 32, detecting the current microbial activity value in real time and transmitting it to the intelligent terminal device 5. The online nitrogen and phosphorus concentration monitor 35 monitors the current nitrogen and phosphorus concentrations of the effluent in the nutrient disposal zone 31, dynamically providing feedback on pollution load and purification effect. The dissolved oxygen sensor 36 monitors the current dissolved oxygen concentration of the effluent, providing a basis for microbial activity regulation.

[0063] Based on the comparison results between the monitoring data and the preset threshold, the intelligent terminal device 5 initiates targeted control measures: When the current microbial activity value is lower than the preset microbial activity threshold, the nitrogen and phosphorus concentration reduction efficiency is lower than the preset nitrogen and phosphorus concentration reduction efficiency threshold, and the current dissolved oxygen concentration is lower than the preset dissolved oxygen concentration threshold, the intelligent terminal device 5 controls the intelligent aeration device 37 to start. The aeration device increases the dissolved oxygen concentration in the water through microporous aeration, providing sufficient oxygen for aerobic microbial metabolism, thereby improving microbial activity and nitrogen and phosphorus degradation efficiency.

[0064] When the current microbial activity value is lower than the preset microbial activity threshold, and the nitrogen and phosphorus concentration reduction efficiency is lower than the preset nitrogen and phosphorus concentration reduction efficiency threshold, but the current dissolved oxygen concentration is greater than or equal to the preset dissolved oxygen concentration threshold, the intelligent terminal device 5 controls the slow-release fertilizer application device 38 to start. The slow-release fertilizer application device 38 precisely applies slow-release fertilizer to the periphery of the bottom sediment substrate 32, supplementing the carbon source and trace elements required for microbial growth, enhancing microbial activity, and strengthening the nitrogen and phosphorus degradation effect.

[0065] When the current nitrogen and phosphorus concentration exceeds the second preset nitrogen and phosphorus concentration threshold, the pollution load is too high, and the intelligent terminal device 5 controls the underwater lighting supplementation device 39 to start. The supplementation device provides sufficient light to the plant community 33, prolongs the photosynthetic duration, promotes plant root growth and nutrient absorption, and at the same time enhances the activity of microorganisms attached to the plant surface, forming a "plant-microorganism" synergistic enhancement of pollution control.

[0066] The online nitrogen and phosphorus concentration monitoring instrument 35 continuously provides feedback on the current nitrogen and phosphorus concentration of the effluent, and the intelligent terminal device 5 compares the data with the emission standards in real time. When the current nitrogen and phosphorus concentration drops below the emission standards, the valve at the outlet of the nutrient consumption area 31 is opened, discharging the compliant effluent into a pre-set drainage ditch. If the standards are not met, ecological purification and intelligent control measures continue to operate until the effluent meets the emission requirements. Throughout the process, the intelligent terminal device 5 monitors the operating status of each module to ensure a stable and efficient pollution control process, achieving effective control of agricultural non-point source pollution.

[0067] The farmland wastewater treatment system provided in this application relies on an ecological combination of "sediment microorganisms-plant community 33" to eliminate nitrogen and phosphorus pollutants in the wastewater through a triple action of microbial degradation, plant root absorption, and sediment adsorption. No chemical agents are required throughout the process, avoiding secondary pollution and aligning with the concept of ecological and environmental protection. Multi-module monitoring data is linked, and the intelligent terminal device 5 can activate targeted control measures such as aeration, slow-release fertilizer application, and supplemental lighting based on changes in microbial activity, nitrogen and phosphorus concentration, and dissolved oxygen content: aeration increases oxygen when oxygen is deficient, nutrients are supplemented when microbial activity is low, and the duration of plant photosynthesis is extended when pollution load is high. This dynamic control mode solves the problem of unstable purification efficiency in traditional ecological wetlands, ensuring that nitrogen and phosphorus removal rates remain at a high level. The farmland wastewater treatment system triggers control actions based on real-time monitoring data, avoiding meaningless energy consumption. For example, the aeration device is only activated when microbial activity is insufficient and dissolved oxygen is lacking, and the supplemental lighting device is only activated when nitrogen and phosphorus concentrations exceed the standard. Meanwhile, targeted regulation measures can extend the effective operating cycle of microbial and plant communities, reduce the frequency of manual maintenance, and lower long-term operation and maintenance costs.

[0068] In one alternative implementation, such as Figure 6 As shown, the farmland wastewater treatment system also includes a wind-solar hybrid power generation device 6, which is communicatively connected to the intelligent terminal device 5, and is also communicatively connected to the farmland wastewater collection device 1, the farmland wastewater desalination device 2, and the farmland wastewater pollution control device 3; wherein: the wind-solar hybrid power generation device 6 is used to generate electricity and supply power to the intelligent terminal device 5 and the various electrical devices in the farmland wastewater collection device 1, the farmland wastewater desalination device 2, and the farmland wastewater pollution control device 3.

[0069] Specifically, the wind-solar hybrid power generation equipment 6 is deployed at a preset installation location, with its core components in standby mode, constantly monitoring environmental wind and solar energy resources. The preset installation location can be an open area or a region with no obstructions around the equipment. The core components may include a 500W wind turbine and six 200W solar photovoltaic panels. When there is natural wind, the wind turbine blades rotate under the force of the wind, converting wind energy into mechanical energy, which is then converted into electrical energy by a generator. When there is sunlight, the solar photovoltaic panels absorb light energy and directly convert it into electrical energy through the photoelectric conversion effect. The wind and solar power generation processes occur simultaneously, achieving a complementary mode of "power generation when there is wind, power generation when there is solar, and simultaneous wind and solar power generation," ensuring continuous power output.

[0070] The electricity generated by the wind turbine and photovoltaic panels is transmitted to a 6000W industrial frequency inverter. The electricity generated by the wind turbine and photovoltaic panels can be either unstable AC or DC. The inverter converts the electricity generated by the wind turbine and photovoltaic panels into stable AC power adapted to the system equipment; this stable AC power can be 220V or 380V. The converted electricity is distributed in two parts: one part is directly supplied to the equipment currently requiring power to meet real-time power needs; the other part is transmitted to four 200Ah batteries for energy storage, with a daily storage capacity of up to 9.6 kWh. During energy storage, the equipment automatically monitors the battery level to prevent overcharging or over-discharging, ensuring battery lifespan, while also storing surplus energy to meet power needs during periods without wind or sunlight.

[0071] The wind-solar hybrid power generation equipment 6 establishes a communication connection with the intelligent terminal equipment 5, transmitting data such as power generation, energy storage capacity, and equipment operating status to the intelligent terminal in real time. After receiving the data, the intelligent terminal equipment 5 performs intelligent power distribution scheduling based on the power demand of the farmland tailwater treatment system, including the farmland tailwater collection equipment 1, farmland tailwater desalination equipment 2, farmland tailwater pollution control equipment 3, soil moisture monitoring equipment 4, and the intelligent terminal equipment 5. Priority is given to ensuring power supply for core equipment: such as the intelligent terminal equipment 5, salinity sensor 12, nitrogen and phosphorus concentration sensor 13, microbial activity monitoring module 34, and other sensors, control motors, intelligent valves, and other key control units, ensuring uninterrupted system regulation functions. Power is supplied to power equipment as needed: according to the progress of the treatment process, power is allocated to power equipment such as the water pump 15, intelligent aeration device 37, slow-release fertilizer dosing device 38, underwater lighting supplementation device 39, and interface evaporation desalination equipment 23, avoiding ineffective energy consumption. During the power supply process, the wind-solar hybrid power generation equipment generated approximately 7.8 kWh of electricity over 6 days, which can fully cover the energy consumption needs of all electrical equipment in the system, achieving energy self-sufficiency.

[0072] The intelligent terminal device 5 continuously monitors the power generation, energy storage capacity, and power consumption of the wind-solar hybrid power generation equipment 6, forming an energy supply and demand balance ledger. When there is sufficient sunlight and strong wind, the power generation is sufficient, prioritizing full-load power supply to all operating equipment, while maximizing the storage of surplus energy. When there is insufficient sunlight and weak wind, the power generation decreases, and the intelligent terminal device 5 automatically adjusts the power supply strategy: prioritizing power supply to core control equipment, appropriately reducing the operating power of non-essential equipment, such as switching the interface evaporation desalination equipment 23 to energy-saving mode, or drawing on battery-stored energy to avoid system shutdown due to insufficient power supply. In the event of extreme weather, the energy stored in the battery can ensure the continuous operation of core equipment until natural energy recovers, ensuring the stability of the system power supply.

[0073] The wind-solar hybrid power generation unit 6 provides power to all electrical equipment in the farmland wastewater collection unit 1, farmland wastewater desalination unit 2, farmland wastewater pollution control unit 3, soil moisture monitoring unit 4, and intelligent terminal unit 5, ensuring that the entire process of "collection-pretreatment-desalination / pollution control-reuse / discharge" is independent of the external power grid. The intelligent terminal unit 5 dynamically coordinates energy allocation and equipment operation based on power generation status and treatment needs, achieving precise matching of "energy supply and treatment demand." This ensures treatment efficiency while reducing energy waste, ultimately achieving green and sustainable operation of the farmland wastewater treatment system.

[0074] The farmland wastewater treatment system provided in this application embodiment utilizes a wind-solar hybrid power generation device 6 to generate electricity from both wind and solar energy. This provides power to all electrical units within the system, including intelligent terminals, sensors, water pumps 15, aeration devices, and supplemental lighting equipment, eliminating reliance on an external power grid and significantly reducing electricity costs. Furthermore, the entire process consumes no fossil fuels, reducing carbon emissions during farmland wastewater treatment and aligning with green and environmentally friendly development principles. The wind-solar hybrid power generation device 6 communicates with the intelligent terminal device 5, enabling real-time transmission of data such as power generation and energy storage status. Based on this data, the intelligent terminal dynamically allocates power: prioritizing power supply to core control equipment such as sensors and control valves, and allocating power to power equipment such as water pumps 15 and aeration devices as needed. Excess power can be stored for backup to cope with extreme weather conditions such as no wind or no sunlight, preventing power outages from halting the wastewater treatment process and improving the stability and reliability of the system. The energy self-sufficiency mode of wind and solar hybrid power generation frees the entire farmland wastewater treatment system from the limitations of power grid coverage. It can be flexibly deployed in remote farmland, mountain farmland and other areas where power grid access is inconvenient, which greatly expands the scope of application of the technology and enables more farmland areas to realize the resource reuse and pollution control of wastewater.

[0075] Based on the above introduction to farmland wastewater treatment systems, such as Figure 7As shown, this application also provides a method for treating farmland wastewater, applied to an intelligent terminal device in the aforementioned farmland wastewater treatment system. The method includes: Step S101: Obtain the current soil moisture of the farmland in the preset area.

[0076] Step S102: When the current soil moisture is less than the preset soil moisture threshold, control the initial tailwater in the farmland tailwater collection device to flow into the farmland tailwater desalination device, and control the farmland tailwater desalination device to desalinate the initial tailwater to obtain desalinated tailwater, and irrigate the preset area of ​​farmland based on the desalinated tailwater.

[0077] Step S103: When the current soil moisture is greater than or equal to the preset soil moisture threshold, control the initial tailwater in the farmland tailwater collection device to flow into the farmland tailwater pollution control device, and control the farmland tailwater pollution control device to treat the initial tailwater to obtain pollution-controlled tailwater. Discharge the pollution-controlled tailwater into the drainage ditch to reduce water pollution.

[0078] For a detailed introduction to methods for treating farmland wastewater, please refer to the above introduction to farmland wastewater treatment systems; further details will not be repeated here.

[0079] Embodiments of the present invention have been described with reference to the accompanying drawings. However, those skilled in the art can make various modifications and variations without departing from the spirit and scope of the invention, and all such modifications and variations fall within the scope defined by the appended claims.

Claims

1. A farmland wastewater treatment system, characterized in that, The farmland wastewater treatment system includes farmland wastewater collection equipment, farmland wastewater desalination equipment, farmland wastewater pollution control equipment, soil moisture monitoring equipment, and intelligent terminal equipment. The farmland wastewater collection equipment is connected to both the farmland wastewater desalination equipment and the farmland wastewater pollution control equipment. The farmland wastewater desalination equipment is connected to a pre-defined area of ​​farmland, and the farmland wastewater pollution control equipment is connected to a pre-defined area of ​​drainage ditches. The farmland wastewater desalination equipment, the farmland wastewater pollution control equipment, and the soil moisture monitoring equipment are all communicatively connected to the intelligent terminal equipment. The farmland tailwater collection device is used to collect the initial tailwater from farmland in a preset area; The soil moisture monitoring device is used to collect the current soil moisture of the farmland in the preset area under the control of the smart terminal device; The intelligent terminal device is used to control the initial tailwater in the farmland tailwater collection device to flow into the farmland tailwater desalination device when the current soil moisture is less than a preset soil moisture threshold, and to control the farmland tailwater desalination device to desalinate the initial tailwater to obtain desalinated tailwater, and to irrigate the preset area farmland based on the desalinated tailwater. The intelligent terminal device is also used to control the initial tailwater in the farmland tailwater collection device to flow into the farmland tailwater pollution control device when the current soil moisture is greater than or equal to the preset soil moisture threshold, and to control the farmland tailwater pollution control device to treat the initial tailwater to obtain pollution-controlled tailwater, and to discharge the pollution-controlled tailwater into the drainage ditch to reduce water pollution.

2. The farmland tailwater treatment system according to claim 1, characterized in that, The farmland tailwater collection equipment includes: a farmland tailwater discharge well, a salinity sensor, a nitrogen and phosphorus concentration sensor, a liquid level sensor, a water pump, and a collection well; wherein: The farmland tailwater discharge well is connected to a submerged pipe at a preset depth corresponding to the preset farmland area, and collects the initial tailwater corresponding to the preset farmland area in a directional manner. The salinity sensor is installed on the farmland tailwater discharge well to detect the initial salinity of the initial tailwater and transmit the initial salinity to the smart terminal device. The nitrogen and phosphorus concentration sensor is installed on the farmland tailwater discharge well to detect the initial nitrogen and phosphorus concentration corresponding to the initial tailwater and transmit the initial nitrogen and phosphorus concentration to the smart terminal device. The liquid level sensor is installed on the farmland tailwater discharge well and is used to detect the initial water level of the initial tailwater in the farmland tailwater discharge well and transmit the initial water level to the smart terminal device. The water pump is connected at one end to the farmland tailwater discharge well and at the other end to the water collection well, and is also connected to the smart terminal device. The intelligent terminal device is used to control the pumping power of the water pump according to at least one of the initial water level, the initial salinity, and the initial nitrogen and phosphorus concentration. The water pump is used, under the control of the intelligent terminal device, to pump the initial tailwater in the farmland tailwater discharge well to the water collection well; The water collection well has one outlet connected to the farmland tailwater desalination equipment and the other outlet connected to the farmland tailwater pollution control equipment.

3. The farmland tailwater treatment system according to claim 2, characterized in that, The water collection well includes tailwater pretreatment equipment and an online water quality monitoring instrument; both the online water quality monitoring instrument and the tailwater pretreatment equipment are communicatively connected to the intelligent terminal device, wherein: The intelligent terminal device is used to control the wastewater pretreatment device to perform desalination pretreatment on the initial wastewater when the initial salinity is greater than a first preset salinity threshold, so as to obtain desalination pretreated wastewater. The online water quality monitoring instrument is used to monitor the pre-treated salinity of the desalination pre-treated effluent online. The intelligent terminal device is used to control the wastewater pretreatment equipment to stop desalination when the pretreated salt content of the wastewater is less than or equal to the first preset salt content threshold. and / or The intelligent terminal device is used to control the wastewater pretreatment device to perform pollution control pretreatment on the initial wastewater when the initial nitrogen and phosphorus concentration is greater than the first preset nitrogen and phosphorus concentration threshold, so as to obtain pollution control pretreated wastewater. The online water quality monitoring instrument is used to monitor the pre-treated nitrogen and phosphorus concentrations of the pre-treated wastewater online. The intelligent terminal device is used to control the wastewater pretreatment equipment to stop pollution control treatment when the pretreatment nitrogen and phosphorus concentration is less than or equal to the first preset nitrogen and phosphorus concentration threshold.

4. The farmland tailwater treatment system according to claim 3, characterized in that, The wastewater pretreatment equipment includes a desalination pretreatment device and a pollution control pretreatment device. The inlet of the desalination pretreatment device is connected to the outlet of the water pump via a first control valve, and the inlet of the pollution control pretreatment device is connected to the outlet of the water pump via a second control valve. The desalination pretreatment device and the pollution control pretreatment device are connected via a third control valve. The first outlet of the desalination pretreatment device is connected to the farmland wastewater desalination device via a fourth control valve, and the second outlet of the desalination pretreatment device is connected to the farmland wastewater pollution control device via a fifth control valve. The first outlet of the pollution control pretreatment device is connected to the farmland wastewater desalination device via a sixth control valve, and the second outlet of the pollution control pretreatment device is connected to the farmland wastewater pollution control device via a seventh control valve. All of the following control valves are communicatively connected to the intelligent terminal device: The intelligent terminal device is used to control the first control valve to open when the initial salinity is greater than the first preset salinity threshold and the initial nitrogen and phosphorus concentration is less than or equal to the first preset nitrogen and phosphorus concentration threshold, so that the desalination pretreatment device can perform desalination pretreatment on the initial effluent; and to control the fourth control valve or the fifth control valve to open based on the current soil moisture. or, The intelligent terminal device is further configured to control the second control valve to open when the initial salinity is less than or equal to the first preset salinity threshold and the initial nitrogen and phosphorus concentration is greater than the first preset nitrogen and phosphorus concentration threshold, so that the pollution control pretreatment device can perform pollution control pretreatment on the initial effluent; and to control the sixth control valve or the seventh control valve to open based on the current soil moisture. or, The intelligent terminal device is further configured to: control the first control valve to open when the initial salinity is greater than the first preset salinity threshold and the initial nitrogen and phosphorus concentration is greater than the first preset nitrogen and phosphorus concentration threshold, so that the desalination pretreatment device can perform desalination pretreatment on the initial effluent; control the third control valve to open when the pretreated salinity of the desalination pretreated effluent is less than or equal to the first preset salinity threshold, so that the pollution control pretreatment device can perform pollution control pretreatment on the initial effluent; and control the sixth or seventh control valve to open based on the current soil moisture. or, The intelligent terminal device is further configured to: control the second control valve to open when the initial salinity is greater than the first preset salinity threshold and the initial nitrogen and phosphorus concentration is greater than the first preset nitrogen and phosphorus concentration threshold, so that the pollution control pretreatment device can perform pollution control pretreatment on the initial effluent; control the third control valve to open when the pretreatment nitrogen and phosphorus concentration corresponding to the pollution control pretreatment effluent is less than or equal to the first preset nitrogen and phosphorus concentration threshold, so that the desalination pretreatment device can perform desalination pretreatment on the initial effluent; and control the fourth or fifth control valve to open based on the current soil moisture.

5. The farmland tailwater treatment system according to claim 1, characterized in that, The farmland tailwater desalination equipment includes: a desalination zone, a bottom desalination device, an interfacial evaporation desalination device, a salt concentration monitoring device, and a light intensity sensor; wherein, the bottom desalination device is located at the bottom of the desalination zone, the interfacial evaporation desalination device is installed on a floating island in the desalination zone, the light intensity sensor is installed on the outer surface of the interfacial evaporation desalination device, and the salt concentration monitoring device is installed inside the desalination zone; wherein: The desalination zone is equipped with a geomembrane at its bottom and on the slopes connected to the pre-defined farmland area to hold the initial tailwater flowing in from the farmland tailwater collection equipment. The bottom desalination equipment includes an ecological bag filter dam filled with modified zeolite and natural zeolite, a movable lifting support, and a control motor. The ecological bag filter dam is on the movable lifting support, and the control motor is installed on the movable lifting support and is communicatively connected to the intelligent terminal device. The salt concentration monitoring device is used to monitor the current salt content at various locations and depths in the desalination zone; The intelligent terminal device is used to control the control motor to move and lift the movable lifting support according to the current salinity corresponding to each position and depth in the desalination zone, so as to drive the ecological bag filter dam to desalinate the initial tailwater at each position and depth. The interface evaporation desalination equipment is used to desalinate the initial tailwater.

6. The farmland tailwater treatment system according to claim 5, characterized in that, The outermost layer of the interface evaporation desalination equipment is a protective cover; the lower functional areas, from bottom to top, are: The bottom container, located at the very bottom of the entire interface evaporation desalination equipment, is fixedly connected to the floating island of the desalination zone and contacts the tailwater. It is the basic load-bearing structure for all components of the interface evaporation desalination equipment. Zeolite, filling the bottom of the container; The upper functional areas, from bottom to top, are as follows: Polystyrene foam, with black cotton thread in the central water conveyance zone; Superhydrophilic filter paper is laid horizontally on top of the polystyrene foam; Carbon nanotube powder is directly sprayed onto the upper surface of superhydrophilic filter paper; The central water transport corridor and salt collection area include: A black cotton thread runs vertically through the pre-reserved holes in the polystyrene foam, with its upper end embedded in the lower surface of the superhydrophilic filter paper and its lower end extending into the zeolite in the bottom container. A salt collection plate is tilted and surrounds the outside of the superhydrophilic filter paper and carbon nanotube powder, located inside the protective cover and above the polystyrene foam.

7. The farmland tailwater treatment system according to claim 1, characterized in that, The farmland tailwater pollution control equipment includes: a nutrient absorption zone, the bottom layer of which is covered with a bottom sediment substrate; the bottom sediment substrate contains microorganisms; and a plant community is planted on the bottom sediment substrate. The nutrient absorption area is used to control pollution in the initial effluent based on the microorganisms and the plant community.

8. The farmland tailwater treatment system according to claim 7, characterized in that, The farmland tailwater pollution control equipment also includes a microbial activity monitoring module, an online nitrogen and phosphorus concentration monitor, a dissolved oxygen sensor, an intelligent aeration device, a slow-release fertilizer dosing device, and an underwater lighting device. The microbial activity monitoring module, the online nitrogen and phosphorus concentration monitor, the dissolved oxygen sensor, the intelligent aeration device, the slow-release fertilizer dosing device, and the underwater lighting device are all communicatively connected to the intelligent terminal device. The microbial activity monitoring module is installed in the sediment matrix to monitor the current microbial activity value of the sediment matrix and transmit the current microbial activity value to the smart terminal device. The nitrogen and phosphorus concentration online monitoring instrument is installed in the nutrient disposal area to monitor the current nitrogen and phosphorus concentration of the initial effluent in the nutrient disposal area and transmit the current nitrogen and phosphorus concentration to the smart terminal device. The dissolved oxygen sensor is installed in the nutrient absorption area to monitor the current dissolved oxygen concentration of the initial effluent in the nutrient absorption area and transmit the current dissolved oxygen concentration to the smart terminal device. The intelligent terminal device is used to calculate the nitrogen and phosphorus concentration reduction efficiency based on the current nitrogen and phosphorus concentration; The intelligent terminal device is further configured to control the intelligent aeration device to perform aeration and increase the current dissolved oxygen concentration when the current microbial activity value is lower than a preset microbial activity threshold, the nitrogen and phosphorus concentration reduction efficiency is lower than a preset nitrogen and phosphorus concentration reduction efficiency threshold, and the current dissolved oxygen concentration is lower than a preset dissolved oxygen concentration threshold; wherein, the intelligent aeration device is installed on the bottom sediment substrate; The intelligent terminal device is further configured to control the slow-release fertilizer application device to apply slow-release fertilizer to increase the current microbial activity value when the current microbial activity value is lower than a preset microbial activity threshold, and the nitrogen and phosphorus concentration reduction efficiency is lower than a preset nitrogen and phosphorus concentration reduction efficiency threshold, but the current dissolved oxygen concentration is greater than or equal to the preset dissolved oxygen concentration threshold; wherein, the slow-release fertilizer application device is installed around the bottom sediment matrix; The intelligent terminal device is also used to control the underwater lighting supplement device to provide supplemental lighting when the current nitrogen and phosphorus concentration is greater than the second preset nitrogen and phosphorus concentration threshold; the underwater lighting supplement device is installed above the plant community.

9. The farmland tailwater treatment system according to claim 1, characterized in that, The farmland wastewater treatment system also includes a wind-solar hybrid power generation device, which is communicatively connected to the intelligent terminal device. Furthermore, the farmland wastewater collection device, the farmland wastewater desalination device, and the farmland wastewater pollution control device are communicatively connected. The wind-solar hybrid power generation equipment is used to generate electricity and supply power to various electrical devices in the smart terminal device, the farmland tailwater collection device, the farmland tailwater desalination device, and the farmland tailwater pollution control device.

10. A method for treating farmland tailwater, characterized in that, Applied to the farmland wastewater treatment system according to any one of claims 1-9, the method comprises: Obtain the current soil moisture of farmland in the preset area; When the current soil moisture is less than a preset soil moisture threshold, the initial tailwater in the farmland tailwater collection device is controlled to flow into the farmland tailwater desalination device, and the farmland tailwater desalination device is controlled to desalinate the initial tailwater to obtain desalinated tailwater, and the farmland in the preset area is irrigated based on the desalinated tailwater. When the current soil moisture is greater than or equal to the preset soil moisture threshold, the initial tailwater in the farmland tailwater collection device is controlled to flow into the farmland tailwater pollution control device, and the farmland tailwater pollution control device is controlled to treat the initial tailwater to obtain pollution-controlled tailwater. The pollution-controlled tailwater is then discharged into the drainage ditch to reduce water pollution.

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