Intelligent Control Device and Method for Phosphorus Identification - Drainage Control - Phosphorus Removal Modularization in Farmland Drainage

Abstract

The present invention discloses a modular intelligent control device and method for phosphorus identification - discharge control - phosphorus removal in farmland drainage, which relates to the technical field of agricultural non-point source pollution control. The device includes a first electrochemistry phosphorus identification module, a discharge control module, an adsorption phosphorus removal module, and a second electrochemistry phosphorus identification module that are sequentially arranged in a ditch along the flow direction of farmland drainage; an active crawler for stirring the phosphorus removal filler to circulate within the adsorption phosphorus removal module is built into the adsorption phosphorus removal module. The present invention can effectively monitor the phosphate concentration of farmland ditch drainage and reasonably arrange adsorption materials to remove excessive phosphate, improve the interception ability of drainage ditches for elements such as phosphorus, and reduce the eutrophication problem of the receiving water body and the surrounding environment; it has the characteristics of high modularity, wide applicability, and strong flexibility, and can be reasonably placed according to the pollution degree of farmland drainage and the pollution prevention and control requirements of the ecological environment.

Description

Technical Field

[0001] The present invention relates to the technical field of agricultural non-point source pollution control, and specifically to an intelligent control device and method for phosphorus identification - discharge control - phosphorus removal modularization in farmland drainage. Background Technique

[0002] In recent years, unscientific agricultural production activities of fertilization have led to excessive phosphates entering the receiving water body through surface runoff, resulting in water eutrophication, which has become one of the major environmental problems of current agricultural non-point source pollution. The basic premise for controlling the water eutrophication problem is to have an accurate and sensitive phosphate concentration monitoring method. Currently, a variety of detection technologies have been developed for phosphates. Among them, phosphate electrochemical sensors have the advantages of high sensitivity, strong selectivity, low cost, fast portability, short response time, etc., and are more suitable for on-line and on-site monitoring. In addition, due to the characteristics of the dispersion and uncertainty of agricultural non-point source pollution, it is difficult to carry out source emission reduction for pollutants. Therefore, a more efficient pollution control technology is selected during the farmland drainage process. Utilizing the current basic interception ability of ditches, high-efficiency adsorption fillers are set, and on this basis, the phosphorus removal function of the ditches is strengthened to improve the loss situation of phosphates during the farmland drainage process.

[0003] Based on the continuous development and innovation of electrochemical sensing detection technology and adsorption materials, the above technologies can be used to achieve on-line real-time detection of phosphorus and control of emissions and reduction of pollution. However, traditional manual collection and monitoring cannot provide timely and accurate detection feedback and equipment control for environmental pollutants. On this basis, the rapid in-depth development of the Internet of Things technology and its integration and expansion with smart agriculture, intelligent monitoring, etc. provide technical support for the modularization and intelligentization of the phosphorus identification - discharge control - phosphorus removal device in the present invention. Summary of the Invention

[0004] The purpose of the present invention is to overcome the defects in the prior art and provide an intelligent control device and method for phosphorus identification - discharge control - phosphorus removal modularization in farmland drainage. This device can effectively improve the interception and treatment ability of ditches for phosphorus under high drainage pressure without changing the basic functions of the original farmland drainage ditches.

[0005] The specific technical solutions adopted by the present invention are as follows:

[0006] In the first aspect, the present invention provides an intelligent control device for phosphorus identification - discharge control - phosphorus removal modularization in farmland drainage, including a first electrochemical phosphorus identification module, a discharge control module, an adsorption and phosphorus removal module, and a second electrochemical phosphorus identification module that are sequentially arranged in a ditch along the farmland drainage flow direction; an active crawler for stirring the phosphorus removal filler to circulate in the adsorption and phosphorus removal module is built in the adsorption and phosphorus removal module.

[0007] Preferably, both the first electrochemical phosphorus recognition module and the second electrochemical phosphorus recognition module include an automatic sampler, a flow meter, a flow velocity meter, and an electrochemical phosphate sensor. The flow meter and the flow velocity meter are used to measure the flow rate and flow velocity of farmland drainage. The automatic sampler is connected to the electrochemical phosphate sensor, and the farmland drainage can enter the electrochemical phosphate sensor through the automatic sampler to realize the recognition of phosphate concentration.

[0008] Further, the electrochemical phosphate sensor is a molybdate-based sensor, which specifically recognizes phosphate by electrochemical cyclic voltammetry.

[0009] Preferably, the drainage control module includes a first water level sensor, a second water level sensor, and a pressure control sluice dam. The pressure control sluice dam can completely cover the cross-section of the flow channel of the ditch where it is located, and its bottom is flush with the bottom of the ditch. A water level pressure sensor flush with the bottom of the ditch is provided at the bottom end of the pressure control sluice dam. The lifting of the gate is adjusted according to the water flow pressure collected by the water level pressure sensor to control the flow-through height. The first water level sensor and the second water level sensor are respectively located upstream and downstream of the pressure control sluice dam.

[0010] Preferably, the phosphorus adsorption and removal module includes a circulating replenishment channel, a frame, a movable track, and phosphorus removal filler. The frame can completely cover the cross-section of the flow channel of the ditch where it is located, and its bottom is flush with the bottom of the ditch. A movable track that can rotate towards the water-facing surface is provided circumferentially on the inner side, and an interception net for preventing the loss of phosphorus removal filler is provided on the outside. The inside of the frame is filled with phosphorus removal filler, and the phosphorus removal filler can be increased, decreased, or replaced through the circulating replenishment channel connected to the outside.

[0011] Further, the frame includes several support rods and two-way electromagnetic knobs provided at the connecting ends of adjacent support rods. The adjacent support rods can be bent under the action of the two-way electromagnetic knobs, and the frame structure can be converted according to the change of the pollutant concentration of the farmland drainage, thereby changing the contact time and contact area between the farmland drainage and the phosphorus removal filler.

[0012] Furthermore, there are 16 two-way electromagnetic knobs and 24 support rods in total. The initial state of the frame is a cuboid structure. Four side edges adjacent to the two ditch walls on both sides are respectively composed of 3 support rods and 4 two-way electromagnetic knobs. The two side edges at the top are connected by 4 support rods respectively, the two side edges at the bottom are connected by 4 support rods respectively, and the side edges at the top and bottom on both sides are connected by 2 support rods respectively.

[0013] Preferably, it further includes an IoT PLC automatic control module; the IoT PLC automatic control module consists of a remote monitoring and transmission analysis unit and a switch control unit. The remote monitoring and data transmission analysis unit is responsible for the calculation, statistics, storage, and analysis and feedback of the basic data of farm production activities and geological and hydrological data. The switch control unit is responsible for the operation management of the relevant equipment in the farmland drainage phosphorus identification - control discharge - phosphorus removal modular device.

[0014] Preferably, the filling rate of the phosphorus removal filler in the adsorption and phosphorus removal module is between 50% and 70%.

[0015] In a second aspect, the present invention provides a method for removing phosphorus from farmland drainage using the intelligent control device for farmland drainage phosphorus identification - control discharge - phosphorus removal modular according to any one of the first aspects, specifically as follows:

[0016] Farmland drainage first passes through the first electro - chemical phosphorus identification module. The water volume and water quality data of the farmland drainage are obtained by the flow meter, flow velocity meter, and electro - chemical sensor. Then, the IoT PLC automatic control module calculates the opening and closing states and operating attributes of each device in the subsequent control discharge module and adsorption and phosphorus removal module; the pressure - controlled sluice in the control discharge module rises and falls under the control of the IoT PLC automatic control module to adjust the overflow height. When the farmland drainage passes through the pressure - controlled sluice, part of it is intercepted, relieving the treatment pressure of the subsequent adsorption and phosphorus removal module and intercepting part of the suspended pollutants at the same time; the first water level sensor and the second water level sensor arranged upstream and downstream of the pressure - controlled sluice are used to correct the lifting height of the pressure - controlled sluice and control the farmland drainage flow; the farmland drainage then enters the adsorption and phosphorus removal module. The frame of the adsorption and phosphorus removal module can change its structure according to the change in the pollutant concentration of the farmland drainage, thereby changing the contact time and contact area between the farmland drainage and the phosphorus removal filler. The inner layer is provided with a rotatable movable track, which can drive the phosphorus removal filler to continuously carry out internal circulation under the action of water flow and motor traction; the circulating replenishment channel arranged at the bottom of the phosphorus removal filler can change the input amount of the phosphorus removal filler and carry out the circulation of the phosphorus removal filler under the control of the IoT PLC automatic control module, ensuring the maximum utilization efficiency of the phosphorus removal filler; finally, the farmland drainage flows through the second electro - chemical phosphorus identification module to monitor the phosphate concentration of the final farmland drainage. At the same time, the IoT PLC automatic control module system combines the comprehensive data of the upstream modules to feedback and correct the control situation of each module device, so that the effluent can meet the requirements of ditch drainage.

[0017] Compared with the prior art, the present invention has the following beneficial effects:

[0018] 1. The present invention has the characteristics of high modularity, wide applicability, and strong flexibility. Multiple groups of phosphorus identification - control discharge - phosphorus removal modules can be placed at the same time, or the same module can be repeatedly connected in series to achieve functions such as multiple control discharges, interceptions, and adsorptions, thereby improving the water quality of farmland drainage and meeting the requirements of the ecological environment;

[0019] 2. The present invention combines an electrochemical sensor for specific recognition of phosphate. Compared with other automatic detection instruments, the phosphate sensor is more suitable for on-line monitoring of the real-time environment and portable and rapid in-situ analysis, providing data support for the rapid control of farmland drainage;

[0020] 3. The present invention designs an efficient phosphorus adsorption and removal device. The filling specifications and frame structure of the adsorption module can be flexibly changed according to the water volume and water quality requirements of the inlet and outlet of the drainage. At the same time, the adsorption filler can be internally replaced and recycled, providing a new feeding method for the filler, which can maximize the use efficiency of the filler;

[0021] 4. The present invention applies the Internet of Things technology to the automatic control and dynamic connection between various module devices, realizing the integration of intelligent recognition, intelligent control and intelligent monitoring and management, and constructing a new type of intelligent agricultural pollution control device. Brief Description of the Drawings

[0022] Figure 1 It is a schematic (top view) drawing of the device of the present invention;

[0023] Figure 2 It is a schematic (front view a, side view b) drawing of the pressure sluice control and drainage module in the device of the present invention;

[0024] Figure 3 It is a schematic (front view a, side view b) drawing of the adsorption filler circulation phosphorus removal module in the device of the present invention;

[0025] Figure 4 It is a schematic (side view) drawing of the different specifications of the cross-section of the external movable frame of the phosphorus removal module in the device of the present invention;

[0026] Figure 5 is Figure 4 a three-dimensional structure schematic drawing of different phosphorus removal modules - external frames in the device of the present invention shown;

[0027] Figure 6 It is a schematic drawing of the use process of the device of the present invention;

[0028] The reference numerals in the drawings are: the first electrochemical phosphorus recognition module 1, the second electrochemical phosphorus recognition module 2, the control and drainage module 3, the first water level sensor 31, the second water level sensor 32, the pressure control sluice 33, the adsorption and phosphorus removal module 4, the circulation replenishment channel 41, the frame 42, the movable track 43, the two-way electromagnetic knob 44, the phosphorus removal filler 45. Detailed Embodiments

[0029] The following further elaborates and explains the present invention in conjunction with the drawings and specific embodiments. The technical features of each embodiment in the present invention can be combined correspondingly without conflict.

[0030] As Figure 1 shown, a smart control device for phosphorus identification - drainage control - phosphorus removal modularization in farmland drainage provided by the present invention mainly includes a first electro - chemical phosphorus identification module 1, a drainage control module 3, an adsorption phosphorus removal module 4, and a second electro - chemical phosphorus identification module 2. The above - mentioned modules can be sequentially installed in the farmland drainage ditch along the flow direction of the farmland drainage. The farmland drainage first passes through the first electro - chemical phosphorus identification module 1 to specifically identify phosphate, then passes through the drainage control module 3 to control the interception of the farmland drainage, then the phosphate is efficiently adsorbed by the adsorption phosphorus removal module 4, and finally the phosphate is specifically identified by the second electro - chemical phosphorus identification module 2, ultimately achieving the functions of phosphorus identification - drainage control - phosphorus removal.

[0031] Next, the structures and connection methods of each module in the device of the present invention will be specifically described.

[0032] In a preferred embodiment of the present invention, the components included in the first electro - chemical phosphorus identification module 1 and the second electro - chemical phosphorus identification module 2 are the same, and both include an auto - sampler, a flow meter, a flow velocity meter, and an electro - chemical phosphate sensor. Among them, the flow meter and the flow velocity meter are used to measure the flow rate and flow velocity of the farmland drainage; the auto - sampler is connected to the electro - chemical phosphate sensor, and the farmland drainage can enter the electro - chemical phosphate sensor through the auto - sampler to realize the identification of the phosphate concentration. The electro - chemical phosphate sensor can adopt a molybdate - based sensor. The electro - chemical phosphorus identification module uses electro - chemical cyclic voltammetry to specifically identify phosphate, and the target water sample is collected by the auto - sampler and completes the electro - chemical sensing process on the molybdate - based sensor. Specifically, the first electro - chemical phosphorus identification module 1 and the second electro - chemical phosphorus identification module 2 adopt electro - chemical analysis under a three - electrode system. The working electrode is a glassy carbon electrode, the counter electrode is a platinum electrode, and the reference electrode is a silver / silver chloride electrode. Cyclic voltammetry is used to perform real - time trace monitoring of the phosphate concentration. The principle of the phosphate identification method is based on the formation of an electro - chemically active phosphorus - molybdenum complex by molybdate and phosphate, and an oxidation - reduction reaction is forced to occur under the action of an electric potential to specifically identify trace phosphate.

[0033] In a preferred embodiment of the present invention, as Figure 2As shown, the control and drainage module 3 mainly includes a first water level sensor 31, a second water level sensor 32 and a pressure control dam 33. The pressure control dam 33 can completely cover the flow channel cross section of the ditch where it is located, and the bottom is flush with the bottom of the ditch, ensuring that farmland drainage can completely flow through this module. A water level pressure sensor flush with the bottom of the ditch is provided at the bottom of the pressure control dam 33. The water flow pressure collected by the water level pressure sensor is used to adjust the gate lifting and lowering to control the flow height. In other words, the lifting height of the pressure control dam 33 is controlled by the water level pressure sensor at its bottom. When the pressure here measured by the water level pressure sensor is higher or lower than the preset pressure of the system, the system controls the pressure control dam 33 to drop or rise a certain height until the water flow pressure here reaches the preset pressure value. The first water level sensor 31 and the second water level sensor 32 are respectively located upstream and downstream of the pressure control dam 33, and are used to record and correct the lifting height of the pressure control dam 33. In actual use, the pressure control dam 33 can be made of impact-resistant and corrosion-resistant electro-galvanized steel plate material. According to the size of the ditch, the length of the dam should be the same as the width of the ditch, and the height of the dam should be the same as the height of the ditch.

[0034] In actual use, when the drainage passes through the control and drainage module 3, the instantaneous interception water level in front of the dam is first determined by the first water level sensor 31 at the front end, and then part of the ditch drainage and settleable suspended pollutants are intercepted through the pressure control dam 33. The second water level sensor 32, the water meter, the flow meter and the first water level sensor 31 jointly determine the water volume data before and after the interception, and timely adjust the interception height of the pressure control dam 33 and the dephosphorization filler addition circulation state of the rear module.

[0035] In a preferred embodiment of the present invention, Figure 3 As shown, the adsorption and phosphorus removal module 4 mainly includes a circulation replenishment channel 41, a frame 42, a movable track 43 and a phosphorus removal filler 45, and the main body is a double-layer structure composed of an external movable frame 42 and an internal movable track 43. The frame 42 can completely cover the flow channel cross-section of the ditch where it is located, and the bottom is flush with the bottom of the ditch, ensuring that the farmland drainage can completely flow through this module. Specifically, the frame 42 includes a plurality of support rods and a plurality of two-way electromagnetic knobs 44, and each two-way electromagnetic knob 44 is arranged at the connecting end of two or three adjacent support rods. Adjacent support rods can be bent under the action of the two-way electromagnetic knob 44, and the structure of the frame 42 can be converted as the pollutant concentration of the farmland drainage changes, thereby changing the contact time and contact area between the farmland drainage and the phosphorus removal filler 45.

[0036] like Figure 4 and 5 As shown, in actual application, it is preferred to set the two-way electromagnetic knobs 44 to a total of 16 and the support rods to a total of 24. Figure 4 (a) and Figure 5As shown in (a), the initial state of the frame 42 is a cuboid structure. The four side edges adjacent to the two ditch walls on both sides are respectively composed of 3 support rods and 4 two-way electromagnetic knobs 44. The two side edges at the top are connected by 4 support rods respectively, the two side edges at the bottom are connected by 4 support rods respectively, and the side edges at the top and bottom on both sides are connected by 2 support rods respectively. Through the setting of the two-way electromagnetic knobs 44, the control of the included angle of the steel pipes in the vertical direction can be realized at angles such as 76° (as shown in Figure c), 90° (as shown in Figure a), 104° (as shown in Figure b), 180° (as shown in Figure d), etc.

[0037] Specifically, Figure 4 It is a schematic diagram of the specific cross-section specifications of four different structures of the external movable frame of the phosphorus adsorption and removal module 4. The cross-section is jointly controlled by 16 two-way electromagnetic knobs arranged inside. The best filler dosing structure is comprehensively selected according to the requirements of water volume and water quality. The electromagnetic knobs adjust the cross-section by controlling the included angle of the clamping edges, specifically as Figure 4 shown, where Figure 4 the structure in (a) can provide the largest accommodation volume for the filler body. Under the condition of the same influent water volume, the size of the filler dosing volume: Figure 5 (a) > Figure 5 (c) > Figure 5 (b) > Figure 5 (d). Therefore, the external movable frame can be adjusted according to the influent water quality to change the filler dosing amount. The specific details are as Figure 5 shown. In addition, when the influent pollution concentration is too high, the adsorption modules can be repeatedly stacked to increase the capacity of the adsorption filler. Finally, it flows through the second electrochemically phosphorus-identifying module, which has the same composition as the aforementioned first electrochemically phosphorus-identifying module. Its main function is to monitor information such as the water volume and water quality of the final effluent, and send the monitoring data to the system terminal through wireless communication technology for storage, analysis, and feedback correction.

[0038] To ensure the stability of the frame 42, the support rods can be made of electro-galvanized solid steel pipes.

[0039] In a preferred embodiment of the present invention, an active track 43 capable of rotating towards the water-facing side is circumferentially provided inside the frame 42, and an interception net for preventing the loss of the phosphorus removal filler 45 is provided outside. The inside of the frame 42 is filled with the phosphorus removal filler 45. The active track 43 is used to stir the phosphorus removal filler 45 to circulate inside the adsorption and phosphorus removal module 4. The active track 43 can adopt a traction chain track. The phosphorus removal filler 45 is increased, decreased or replaced through a circulation replenishment channel 41 connected to the outside. Specifically, the circulation replenishment channel 41 is installed at the bottom of the adsorption and phosphorus removal module 4, and the filler can be increased, decreased or replaced according to requirements without affecting the conversion of the frame 42 and the rotation of the active track 43. The circulation replenishment channel 41 can adopt an electro-galvanized steel hollow pipe material, and the specific size depends on the selection of the adsorption filler. Its pipe diameter should be slightly larger than twice the diameter of the commonly used adsorption filler, and the diameter size is preferably 0.2 - 0.4 m.

[0040] During actual use, when the drained water passes through the adsorption and phosphorus removal module, the filler can slowly circulate inside the frame under the action of the water flow and the inner chain track, improving the adsorption efficiency. Before reaching the maximum critical adsorption capacity during continuous adsorption, the system conducts a filler replenishment cycle through a two-way pipeline (i.e., the circulation replenishment channel 41) to avoid the problem of exceeding the standard of the effluent water quality due to reaching the adsorption limit.

[0041] In a preferred embodiment of the present invention, the filling rate of the phosphorus removal filler 45 in the adsorption and phosphorus removal module should be between 50% and 70%. Too low a filling rate will lead to low treatment efficiency, while too high a filling rate will lead to an increase in system resistance and a decrease in treatment efficiency. The phosphorus removal filler 45 should meet the requirements of not affecting the ecological environment, not floating on the water surface, having a large throughput, small resistance, high separation efficiency, strong production capacity, and large operation flexibility, etc. The present invention provides five high-efficiency adsorption fillers as reasonable choices for actual treatment: namely volcanic rock, medical stone, biochar, zeolite, clay ceramsite, etc. Other fillers that meet the application requirements can also be used in this adsorption module.

[0042] To ensure the stability of the active track 43, it can be made of corrosion-resistant electro-galvanized steel of the same material as the support rod. The width of the track is the same as the width of the ditch, and the length of the track is consistent with the cross-sectional perimeter.

[0043] In a preferred embodiment of the present invention, the modular device for phosphorus recognition - drainage control - phosphorus removal of farmland drainage also includes an IoT PLC automatic control module. The IoT PLC automatic control module consists of a remote monitoring and transmission analysis unit and a switch control unit. Among them, the remote monitoring and data transmission analysis unit is responsible for the calculation, statistics, storage, and analysis and feedback of the basic data of farm production activities and geological and hydrological data, and can send operation instructions to the switch control unit; after receiving the operation instructions from the remote monitoring and data transmission analysis unit, the switch control unit can conduct operation management and control on the relevant equipment in the modular device for phosphorus recognition - drainage control - phosphorus removal of farmland drainage.

[0044] In actual use, the devices connected under each module can be flexibly increased, decreased or replaced according to the actual situation, including electrochemical sensors, flow meters, water level sensors, pressure gates, adsorption packing bodies, etc. The first electrochemical phosphorus recognition module 1, the control and drainage module 3, the adsorption and phosphorus removal module 4 and the second electrochemical phosphorus recognition module 2 can be connected in series multiple times and combined flexibly according to the actual situation.

[0045] Using the above-mentioned intelligent control device for phosphorus recognition, control and removal in farmland drainage modularly, the present invention also provides a method for removing phosphorus from farmland drainage, as Figure 6 shown below:

[0046] Farmland drainage first passes through the first electrochemical phosphorus recognition module 1. The water quantity and water quality data of the farmland drainage are obtained by the flow meter, the flow velocity meter and the electrochemical sensor. Then, the opening and closing states and operating properties of each device in the subsequent control and drainage module 3 and the adsorption and phosphorus removal module 4 are calculated automatically by the Internet of Things PLC automatic control module. The pressure control gate 33 in the control and drainage module 3 rises and falls under the control of the Internet of Things PLC automatic control module to adjust the overflow height. When the farmland drainage passes through the pressure control gate 33, part of it is intercepted, relieving the treatment pressure of the subsequent adsorption and phosphorus removal module 4 and intercepting part of the suspended pollutants at the same time. The first water level sensor 31 and the second water level sensor 32 arranged upstream and downstream of the pressure control gate 33 are used to correct the rising and falling height of the pressure control gate 33 and control the farmland drainage flow. The farmland drainage then enters the adsorption and phosphorus removal module 4. The frame 42 of the adsorption and phosphorus removal module 4 can change its structure according to the change of the pollutant concentration of the farmland drainage, thereby changing the contact time and contact area between the farmland drainage and the phosphorus removal packing 45. The inner layer is provided with a rotatable movable track 43, which can drive the phosphorus removal packing 45 to continuously carry out internal circulation under the action of water flow and motor traction. The circulation replenishment channel 41 arranged at the bottom end of the phosphorus removal packing 45 can change the input amount of the phosphorus removal packing 45 and carry out the circulation of the phosphorus removal packing 45 under the control of the Internet of Things PLC automatic control module, ensuring the maximum utilization efficiency of the phosphorus removal packing 45. Finally, the farmland drainage flows through the second electrochemical phosphorus recognition module 2 to monitor the phosphate concentration of the final farmland drainage. At the same time, the Internet of Things PLC automatic control module system combines the comprehensive data of the upstream modules to feedback and correct the control situation of the use of each module device, so that the effluent can meet the requirements of ditch drainage.

[0047] The following combines examples to further illustrate the phosphorus removal effect of the device of the present invention.

[0048] Example 1

[0049] In this example, the farmland ditches in Xiuzhou District of a certain city are used as the experimental object to verify the feasibility of the device of the present invention, as follows:

[0050] 1) This device is installed in the middle section of the ditch drainage. A total of 6 modules are set up, namely the electrochemical phosphorus recognition module, the drainage control module, the adsorption and phosphorus removal module, the drainage control module, the adsorption and phosphorus removal module, and the electrochemical phosphorus recognition module. The distance between the first adsorption and phosphorus removal module and the second drainage control module is 20m, and the distance between the remaining adjacent modules is 1m. The filler in the adsorption and phosphorus removal module is modified volcanic rock, with a size of about 4-8mm.

[0051] 2) The first electrochemical phosphorus recognition module conducts real-time monitoring after heavy rain runoff occurs in the farmland. The interval of the automatic sampler is set to 5 minutes. Subsequently, the electrochemical sensor converts the phosphate concentration into an electrical signal under the drive of the electric potential, and the maximum instantaneous concentration of phosphate is obtained as 0.51mg / L, and the average concentration is 0.39mg / L. At the same time, the data of the first-stage flowmeter and flow velocity meter are sent to the control terminal of the Internet of Things system, and the phosphorus loss flux in this period is calculated to be 0.13g / s.

[0052] 3) At this time, the control terminal of the Internet of Things system comprehensively calculates and adjusts the parameters of each module according to the phosphorus loss flux. The interception height of the first drainage control module rises to 0.4m, and each electromagnetic knob in the first adsorption and phosphorus removal module is controlled to be adjusted to Figure 5 (a) Specification, the filling rate of the phosphorus removal filler is 65%, and the rotation speed of the inner-layer chain track is 1r / min; the interception height of the second drainage control module rises to 0.2m, and each electromagnetic knob in the second adsorption and phosphorus removal module is adjusted to Figure 5 (c), the filling rate of the phosphorus removal filler is 50%, and the rotation speed of the inner-layer chain track is 2r / min.

[0053] 4) The terminal electrochemical phosphorus recognition module monitors synchronously with the initial electrochemical phosphorus recognition module, and the maximum instantaneous concentration of phosphate is obtained as 0.28mg / L, and the average concentration is 0.26mg / L. It is higher than the preset control concentration of 0.20mg / L. At this time, the control terminal feeds back and adjusts the module parameters. The interception height of the first drainage control module rises to 0.4m, and each electromagnetic knob in the first adsorption and phosphorus removal module is controlled to be adjusted to Figure 5 (a) Specification, the filling rate of the phosphorus removal filler is 70%, and the rotation speed of the inner-layer chain track is 1r / min; the interception height of the second drainage control module rises to 0.3m, and each electromagnetic knob in the second adsorption and phosphorus removal module is adjusted to Figure 5 (c), the filling rate of the phosphorus removal filler is 60%, and the rotation speed of the inner-layer chain track is 2r / min.

[0054] 5) The second electrochemical phosphorus recognition module obtains the maximum instantaneous concentration of phosphate as 0.16mg / L, which meets the farmland drainage requirements of the system. Keep the parameters of each above-mentioned module unchanged. At the same time, according to the parameters of each module and the dynamic adsorption capacity and adsorption efficiency of the adsorption material, the circulation time of the phosphorus removal filler is calculated to be 2h.

[0055] 6) The above-mentioned adsorption-saturated volcanic rock was desorbed using 1 mol / L hydrochloric acid during the resource recovery process. The basic parameters of the water quality after desorption were pH=3.24 and TP=153.21 mg / L. The resource recovery pathway of the desorbed liquid will be discussed later.

[0056] The present invention can effectively monitor the phosphate concentration of farmland ditch drainage and reasonably arrange adsorption materials to remove excess phosphate, improve the interception capacity of drainage ditches for elements such as phosphorus, and reduce the eutrophication problem of receiving water bodies and surrounding environments. The present invention is mainly arranged inside the ditch. When farmland drainage enters the ditch, it first passes through the electrochemical phosphorus identification module, and uses a flow meter, a flow meter, an automatic sampler and an electrochemical sensor to monitor the flow rate and flow of the drainage and specifically identify the phosphate concentration; a pressure gate dam and front and rear end water level sensors are arranged under the control and discharge module, and the lifting height of the gate dam is adjusted according to the discharge requirements and the monitoring indicators of the front phosphorus identification module, the instantaneous flow of farmland drainage is controlled, and the operating pressure of the subsequent modules is reduced; an automatic feeding circulation device of fillers with elastically variable specifications is arranged in the adsorption and phosphorus removal module, which can flexibly adjust the dosage and contact area of the adsorption filler according to the phosphate concentration of the drainage, and maximize the adsorption efficiency of the filler. The present invention has the characteristics of high modularization, wide applicability, and strong flexibility, and can be reasonably placed according to the pollution degree of farmland drainage and the pollution prevention and control requirements of the ecological environment.

[0057] The above-described embodiment is only a preferred solution of the present invention, but it is not intended to limit the present invention. A person skilled in the relevant technical field may make various changes and modifications without departing from the spirit and scope of the present invention. Therefore, any technical solution obtained by equivalent replacement or equivalent transformation falls within the protection scope of the present invention.

Claims

1. A modular intelligent control device for phosphorus recognition - drainage control - phosphorus removal in farmland drainage, characterized in that, It includes a first electrochemically phosphorus-identifying module (1), a drainage control module (3), an adsorption and phosphorus-removing module (4), and a second electrochemically phosphorus-identifying module (2) that are sequentially arranged in a ditch along the flow direction of farmland drainage; an active track (43) for agitating the phosphorus-removing filler (45) to circulate within the adsorption and phosphorus-removing module (4) is built in the adsorption and phosphorus-removing module (4). The adsorption and phosphorus-removing module (4) includes a circulation replenishment channel (41), a frame (42), an active track (43), and a phosphorus-removing filler (45); the frame (42) can completely cover the cross-section of the flow channel of the ditch where it is located, with the bottom flush with the bottom of the ditch, and an active track (43) that can rotate towards the water-facing surface is arranged circumferentially on the inner side, and an interception net for preventing the loss of the phosphorus-removing filler (45) is arranged on the outer side; the inside of the frame (42) is filled with the phosphorus-removing filler (45), and the phosphorus-removing filler (45) can be increased, decreased, or replaced through the circulation replenishment channel (41) connected to the outside. The frame (42) includes a number of support rods and two-way electromagnetic knobs (44) arranged at the connecting ends of adjacent support rods. The adjacent support rods can be bent under the action of the two-way electromagnetic knobs (44), and the structure of the frame (42) can be converted according to the change in the pollutant concentration of the farmland drainage, thereby changing the contact time and contact area between the farmland drainage and the phosphorus-removing filler (45).

2. The intelligent control device for phosphorus recognition - drainage control - phosphorus removal modularization in farmland drainage according to claim 1, wherein, Both the first electrochemically phosphorus-identifying module (1) and the second electrochemically phosphorus-identifying module (2) include an automatic sampler, a flowmeter, a flow velocity meter, and an electrochemical phosphate sensor. The flowmeter and the flow velocity meter are used to measure the flow rate and flow velocity of the farmland drainage; the automatic sampler is connected to the electrochemical phosphate sensor, and the farmland drainage can enter the electrochemical phosphate sensor through the automatic sampler to realize the identification of the phosphate concentration.

3. The intelligent control device for phosphorus recognition - drainage control - phosphorus removal modularization in farmland drainage according to claim 2, wherein, The electrochemical phosphate sensor is a molybdate-based sensor, which specifically identifies phosphate by using electrochemical cyclic voltammetry.

4. The intelligent control device for farmland drainage phosphorus recognition - control drainage - phosphorus removal modularization according to claim 1, characterized in that, The drainage control module (3) includes a first water level sensor (31), a second water level sensor (32), and a pressure control sluice (33); the pressure control sluice (33) can completely cover the cross-section of the flow channel of the ditch where it is located, with the bottom flush with the bottom of the ditch. A water level pressure sensor flush with the bottom of the ditch is provided at the bottom end of the pressure control sluice (33), and the lifting of the gate is adjusted according to the magnitude of the water flow pressure collected by the water level pressure sensor to control the over-flow height; the first water level sensor (31) and the second water level sensor (32) are respectively located upstream and downstream of the pressure control sluice (33).

5. The intelligent control device for phosphorus identification - drainage control - phosphorus removal modularization in farmland drainage according to claim 1, characterized in that, There are 16 two-way electromagnetic knobs (44) in total, and 24 support rods in total; the frame (42) is initially in a cuboid structure. Each of the four side edges adjacent to the two ditch walls on both sides is composed of 3 support rods and 4 two-way electromagnetic knobs (44). The two side edges at the top are connected by 4 support rods respectively, the two side edges at the bottom are connected by 4 support rods respectively, and the side edges at the top and bottom on both sides are connected by 2 support rods respectively.

6. The intelligent control device for phosphorus recognition - drainage control - phosphorus removal modularization in farmland drainage according to claim 1, characterized in that, It also includes an IoT PLC automatic control module; the IoT PLC automatic control module consists of a remote monitoring and data transmission analysis unit and a switch control unit. The remote monitoring and data transmission analysis unit is responsible for the calculation, statistics, storage, and analysis feedback of the basic data of farm production activities and geological and hydrological data. The switch control unit is responsible for the operation management of related equipment in the farmland drainage phosphorus identification-control discharge-removal phosphorus modular device.

7. The intelligent control device for phosphorus identification - drainage control - phosphorus removal modularization in farmland drainage according to claim 1, characterized in that, The filling rate of the phosphorus removal filler (45) in the adsorption phosphorus removal module (4) is between 50% and 70%.

8. A method for removing phosphorus from farmland drainage using the intelligent control device for phosphorus identification - drainage control - phosphorus removal modularization of farmland drainage according to any one of claims 1 to 7, characterized in that, Specifically as follows: Farmland drainage first passes through the first electrochemical phosphorus identification module (1), and the water volume and water quality data of the farmland drainage are obtained by the flow meter, flow velocity meter, and electrochemical sensor. Then, the IoT PLC automatic control module calculates the opening and closing states and operating attributes of each device in the subsequent control discharge module (3) and adsorption phosphorus removal module (4); the pressure control sluice (33) in the control discharge module (3) rises and falls under the control of the IoT PLC automatic control module to adjust the overflow height. When the farmland drainage passes through the pressure control sluice (33), part of it is intercepted, relieving the treatment pressure of the subsequent adsorption phosphorus removal module (4) and intercepting part of the suspended pollutants at the same time; the first water level sensor (31) and the second water level sensor (32) are respectively arranged upstream and downstream of the pressure control sluice (33) to correct the lifting height of the pressure control sluice (33) and control the farmland drainage flow; the farmland drainage then enters the adsorption phosphorus removal module (4). The frame (42) of the adsorption phosphorus removal module (4) can change its structure according to the change of the pollutant concentration of the farmland drainage, thereby changing the contact time and contact area between the farmland drainage and the phosphorus removal filler (45). The rotatable movable track (43) arranged inside can drive the phosphorus removal filler (45) to continuously carry out internal circulation under the traction of water flow and the motor; the circulating replenishment channel (41) arranged at the bottom of the phosphorus removal filler (45) can change the input amount of the phosphorus removal filler (45) and carry out the circulation of the phosphorus removal filler (45) under the control of the IoT PLC automatic control module to ensure the maximum utilization efficiency of the phosphorus removal filler (45); finally, the farmland drainage flows through the second electrochemical phosphorus identification module (2) to monitor the phosphate concentration of the final farmland drainage. At the same time, the IoT PLC automatic control module system combines the comprehensive data of the upstream modules to feedback and correct the use control situation of each module device, so that the effluent can meet the requirements of ditch drainage.

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