Precision Treatment System and Control Method for Agricultural Non-point Source Phosphorus Pollution Based on Enrichment and Reuse

Abstract

This invention discloses a precision treatment system and control method for farmland non-point source phosphorus pollution based on enrichment and reuse, comprising a water control unit, a purification unit, a desorption unit, and a power supply unit; the purification unit is installed inside the water control unit, and the desorption unit is connected externally to the water control unit; the water control unit is used for water flow control; the purification unit is used to purify farmland non-point source polluted water, and the purification unit includes directional phosphorus adsorption matrix filler, which is lanthanum-based coated molecular spheres and lanthanum-based coated molecular bricks; the desorption unit is used to perform desorption when the phosphorus adsorption capacity of the purification unit is saturated; the power supply unit is used to supply power to the system; thus, precision treatment of farmland non-point source phosphorus pollution based on enrichment and reuse is achieved.

Description

Technical Field

[0001] This invention relates to the field of farmland non-point source pollution control, specifically to a precision control system and control method for farmland non-point source phosphorus pollution based on enrichment and reuse. Background Technology

[0002] Non-point source pollution from farmland occurs when nutrients from the improper use of fertilizers, driven by precipitation and influenced by topography, are released into farmland runoff, such as surface runoff, farmland drainage, and groundwater seepage. This discharges nutrients like nitrogen and phosphorus, along with organic and inorganic pollutants like pesticides and heavy metals, contaminating nearby receiving water bodies. This pollution is characterized by its randomness, dispersion, and wide reach. Farmland non-point source pollution has become a key factor affecting the water quality of rivers, lakes, and other watersheds, hindering the achievement of green, sustainable, and high-quality agricultural development. Furthermore, phosphate fertilizer production relies heavily on limited phosphate rock reserves; from a resource strategy perspective, it is necessary to further improve the efficiency of phosphorus utilization in farmland. Farmland runoff during fertilization is essentially fertilizer water; therefore, concentrating the nutrients in farmland runoff and recycling it back to farmland to supply crop growth is a solution that simultaneously addresses environmental pollution and improves fertilizer utilization efficiency.

[0003] In the existing technology, the main ways to reduce and reuse nutrients are ecological pond method, plant absorption method and filler adsorption method: (1) Ecological pond is obtained by using surrounding pits, ponds and wetlands for waterway and ecological transformation. Through the control of gate valves, the high concentration of surface runoff in the early stage enters the ecological pond, and the farmland is given priority in water allocation in the later stage. Ecological pond method has produced good benefits of "zero storage and whole extraction" of non-point source sewage, but this method requires a sufficient proportion of land area, the amount of engineering is large, and it cannot be fully applied to all scenarios. (2) Plant absorption method is to plant aquatic plants in the path of farmland runoff (such as ditches, pits, etc.), and the harvested plants are made into organic fertilizer or carbonized and returned to the field. Plant absorption method has the effect of beautifying the environment, but its absorption efficiency is still limited, it is highly sensitive to temperature and season, and is very dependent on human management. (3) Filler adsorption method is to use high adsorption rate and slow release filler to be deployed in the checkpoints of farmland runoff, and the filler after adsorption saturation is directly returned to the field as slow release fertilizer. Currently, numerous adsorption packing materials have been developed, and their adsorption capacity limits are constantly being broken. The advantages of packing adsorption methods are that they are not limited by temperature and season, and maintenance is convenient, requiring only the replacement of the packing material. The disadvantages are that the packing material itself is expensive, so the cost of replacing the packing material is also high. In addition, direct application to the field may cause secondary pollution, thereby further increasing the cost of pollution control. Summary of the Invention

[0004] The purpose of this invention is to provide a precision treatment system and control method for farmland non-point source phosphorus pollution based on enrichment and reuse, thereby overcoming the shortcomings of the existing technologies.

[0005] To achieve the above objectives, the technical solution of the present invention is as follows:

[0006] A precision treatment system for non-point source phosphorus pollution in farmland based on enrichment and reuse includes:

[0007] Water control unit, purification unit, desorption unit, and energy supply unit;

[0008] The purification unit is installed inside the water control unit, and the desorption unit is connected to the outside of the water control unit.

[0009] The water control unit is used for water flow control in the system.

[0010] The purification unit is used to purify non-point source pollution water in farmland. The purification unit includes a directional phosphorus absorption matrix filler, which is a lanthanum-based coated molecular sphere and a lanthanum-based coated molecular brick.

[0011] The desorption unit is used to perform desorption when the phosphorus adsorption capacity of the purification unit is saturated;

[0012] The power supply unit is used to supply power to the system.

[0013] Furthermore, the water control unit includes a container, a sliding drain valve, a filling valve, a wireless data acquisition unit, and a phosphorus concentration identification sensor. The sliding drain valve and the filling valve are installed at the front and rear ends of the container in the direction of the drain water flow. The wireless data acquisition unit is located outside the filling valve, and the lower end is connected to the phosphorus concentration identification sensor, which is inserted into the drain.

[0014] Furthermore, the container is equipped with a partition that divides the container into an upper half and a lower half, with the volume ratio of the upper half to the lower half ranging from 1:1 to 2:1. The directional phosphorus-absorbing matrix filler is set in the upper half of the container. The partition and the bottom of the container are equipped with locking points for sliding limit of the sliding drain valve. The area ratio of the sliding drain valve to the filling valve is 1:2.

[0015] Furthermore, the desorption unit includes a desorption liquid container, a desorption liquid, and a flushing pump. The desorption liquid container is filled with desorption liquid and is externally connected to the flushing pump, which is connected to the outside of the water filling valve through a pipe.

[0016] Furthermore, the directional phosphorus adsorption matrix filler includes lanthanum-coated molecular spheres and lanthanum-coated molecular bricks, with lanthanum-coated molecular bricks disposed on both sides of the lanthanum-coated molecular spheres, and the total volume ratio of lanthanum-coated molecular spheres to lanthanum-coated molecular bricks is 2:1.

[0017] Furthermore, the power supply unit uses solar panels, which are installed above the housing; the wireless data acquisition unit uses a LoRa wireless data acquisition unit.

[0018] Furthermore, the flushing pump is a submersible pump with controllable water flow rate and a rated flow rate of 100~180 m³ / h. 3 / h.

[0019] Furthermore, the preparation method of the directional phosphorus-absorbing matrix filler includes the following steps:

[0020] Sa, prepare a 0.4 mol / L La(NO3)3·6H2O solution, and optionally add a Fe(NO3)3·9H2O solution with a concentration not exceeding 0.4 mol / L;

[0021] Sb. Place the zeolite molecular bricks and zeolite molecular balls into the solution and stir to mix them thoroughly. The solid-liquid ratio is 0.1~1 kg / L. Then, gradually add NaOH solution with a solid-liquid ratio of 0.1~2 kg / L and a concentration of 1 mol / L to treat the solution. Let it stand and soak for 8~12 h before taking it out.

[0022] Sc is calcined in a muffle furnace at 200~300 ℃ for 4~6 h, and then removed after the temperature drops to room temperature to obtain lanthanum-based coated molecular spheres and lanthanum-based coated molecular bricks.

[0023] Furthermore, the components of the desorption solution include:

[0024] The wood vinegar has a volume fraction of 90%–98% and a pH value of 3.5–5.

[0025] The potassium chloride solution has a mass fraction of 2%.

[0026] The citric acid solution has a mass fraction of 0.5% to 1%.

[0027] A control method for a precision treatment system for non-point source phosphorus pollution in farmland based on enrichment-reuse includes the following steps:

[0028] S1, Fertilizer and Water Period

[0029] S1.1, Operate the water control unit, slide the drain valve to the lower half of the container, raise the water filling valve, and the water flow will generate an upward flow and enter the purification unit. The directional phosphorus adsorption matrix filler will quickly adsorb the phosphorus in the drain, thus completing the fertilizer water purification.

[0030] S1.2 When the phosphorus concentration sensor detects that the phosphorus concentration exceeds the limit, the data is transmitted to the terminal via the wireless data acquisition device to indicate that adsorption is saturated and desorption is required.

[0031] S1.3, the sliding drain valve slides to the upper part of the container, the filling valve descends, the flushing pump is turned on, the desorption liquid is drawn into the container, and the directional phosphorus adsorption matrix packing is soaked;

[0032] S1.4 After desorption is completed, the flushing pump is connected to the external water filling structure through a pipeline. The flushing pump is turned on, and the sliding drain valve is slid to the lower half of the container for rapid flushing.

[0033] S1.5. Phosphorus is returned to the field along with the desorbed solution, thus completing the reuse of irrigation water;

[0034] S2, Non-fertile water period

[0035] S2.1, the sliding drain valve slides to the upper part of the container, the filling valve rises, and normal drainage occurs.

[0036] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0037] (1) The enrichment-reuse precision treatment system for non-point source phosphorus pollution in farmland provided by the present invention, through the scientific structural design of water control unit, purification unit, desorption unit and energy supply unit, allows the purification unit to adsorb phosphorus during the fertilization and irrigation period when phosphorus is not saturated, thereby achieving the purpose of pollution control; and when the purification unit adsorbs phosphorus and reaches saturation, the desorption unit desorbs it, thereby achieving the reuse of the purification unit, and finally removing phosphorus pollution from emergency drainage during the fertilization and irrigation period of farmland in a targeted, rapid and efficient manner, thus achieving precise treatment of agricultural non-point source pollution.

[0038] (2) The purification unit of the present invention uses directional adsorption matrix filler. Based on the system structure, it can be recycled and reused in situ, which significantly improves the service life of the matrix filler. At the same time, the nutrients in the directional adsorption matrix filler can also be recovered and reused, avoiding the risk of secondary pollution caused by direct return of adsorption matrix filler to the field in the prior art, further reducing the cost of pollution control, and breaking through the application bottleneck of traditional adsorption filler in the control of non-point source pollution in farmland.

[0039] (3) The desorption solution prepared in this invention has a high desorption rate. When the phosphorus adsorption capacity of the directional adsorption matrix filler is saturated, it can be desorbed in time, thereby ensuring continuous purification. Moreover, the desorption solution can promote plant / crop growth, has no toxic side effects, and is environmentally friendly. Attached Figure Description

[0040] The disclosure of this invention is illustrated with reference to the accompanying drawings. It should be understood that the drawings are for illustrative purposes only and are not intended to limit the scope of protection of this invention. In the drawings, the same reference numerals are used to refer to the same parts. Wherein:

[0041] Figure 1 This is a schematic diagram of the system structure of the present invention;

[0042] Figure 2 This is a flowchart of the system control method of the present invention;

[0043] Figure 3 This is a schematic diagram illustrating the effect of Example 2;

[0044] Figure 4 This is a schematic diagram illustrating the effect of Example 3.

[0045] The diagram is labeled as follows: 1. Container; 2. Sliding drain valve; 3. Water filling valve; 4. Wireless data acquisition device; 5. Phosphorus concentration identification sensor; 6. Directional phosphorus adsorption matrix packing; 7. Desorption liquid container; 8. Desorption liquid; 9. Flushing pump; 10. Solar panel; 11. Partition. Detailed Implementation

[0046] It is readily understood that, based on the technical solution of this invention, those skilled in the art can propose various interchangeable structural methods and implementations without altering the essential spirit of the invention. Therefore, the following detailed embodiments and accompanying drawings are merely illustrative examples of the technical solution of this invention and should not be considered as the entirety of the invention or as limitations or restrictions on the technical solution of this invention.

[0047] The technical solution of this application will now be described in detail with reference to the accompanying drawings. The description of exemplary embodiments is merely for illustrative purposes and is by no means a limitation on the invention or its application or use.

[0048] Example 1

[0049] like Figure 1 As shown, a precision treatment system for farmland non-point source phosphorus pollution based on enrichment and reuse includes:

[0050] The container 1 has an internal partition 11, which divides the container 1 into an upper half and a lower half. The volume ratio of the upper half to the lower half is 1:1 to 2:1. The directional phosphorus adsorption matrix filler 6 is set in the upper half of the container 1. The sliding drain valve 2 and the water filling valve 3 are installed at the front and rear ends of the container 1 in the direction of the drainage flow. The partition 11 and the bottom of the container 1 are provided with locking points for the sliding limit of the sliding drain valve 2. The area ratio of the sliding drain valve 2 to the water filling valve 3 is 1:2.

[0051] The wireless data collector 4 is located outside the water filling valve 3, and the lower end is connected to the phosphorus concentration identification sensor 5, which is inserted into the drainage.

[0052] The solar panel 10 is connected to the sliding drain valve 2, the water filling valve 3, the wireless data collector 4, and the phosphorus concentration identification sensor 5, respectively, and is located above the container 1 to provide power to the system.

[0053] The directional phosphorus absorption matrix filler 6 is used to purify non-point source pollution water in farmland. It includes lanthanum-coated molecular spheres and lanthanum-coated molecular bricks. Lanthanum-coated molecular bricks are placed on both sides of the lanthanum-coated molecular spheres, and the volume ratio of lanthanum-coated molecular spheres to lanthanum-coated molecular bricks is 2:1.

[0054] The desorption unit, used to perform desorption when the phosphorus adsorption capacity of the purification unit is saturated, includes a desorption liquid container 7, a desorption liquid 8, and a flushing pump 9. The desorption liquid container 7 is filled with the desorption liquid 8 and is externally connected to the flushing pump 9, which is connected to the outside of the water filling valve 3 via a pipe. The flushing pump 9 is a submersible pump with controllable water flow rate and a rated flow rate of 100~180 m³ / h. 3 / h.

[0055] The preparation method of the above-mentioned directional phosphorus adsorption matrix filler 6 includes the following steps:

[0056] Sa, prepare a 0.4 mol / L La(NO3)3·6H2O solution, and, depending on the specific circumstances, optionally add a Fe(NO3)3·9H2O solution with a concentration not exceeding 0.4 mol / L;

[0057] Sb. Place the zeolite molecular bricks and zeolite molecular balls into the solution and stir to mix them thoroughly. The solid-liquid ratio is 0.1~1 kg / L. Then, gradually add NaOH solution with a solid-liquid ratio of 0.1~2 kg / L and a concentration of 1 mol / L to treat the solution. Let it stand and soak for 8~12 h before taking it out.

[0058] Sc is calcined in a muffle furnace at 200~300 ℃ for 4~6 h, and then removed after the temperature drops to room temperature to obtain lanthanum-based coated molecular spheres and lanthanum-based coated molecular bricks.

[0059] Desorption solution 8 comprises the following components:

[0060] The wood vinegar has a volume fraction of 90%–98% and a pH value of 3.5–5.

[0061] The potassium chloride solution has a mass fraction of 2% to 4%.

[0062] The citric acid solution has a mass fraction of 0.5% to 1%.

[0063] Additionally, a calcium chloride solution with a mass fraction of 2% to 4% may be added to the desorption solution 8 as needed.

[0064] like Figure 2 As shown, the control method of the above-mentioned precision treatment system for farmland non-point source phosphorus pollution based on enrichment-reuse includes the following steps:

[0065] S1, Fertilizer and Water Period

[0066] S1.1, Operate the water control unit, slide the drain valve 2 to the lower half of the container 1, lift the water filling valve 3, and the water flow will generate an upward flow and enter the purification unit. Then the directional phosphorus adsorption matrix filler 6 will quickly adsorb the phosphorus in the drainage and complete the fertilizer water purification.

[0067] S1.2 When the phosphorus concentration sensor 5 detects that the phosphorus concentration exceeds the limit (this value can be set according to specific usage and requirements), the data is transmitted to the terminal via the wireless data acquisition device 4 to indicate adsorption saturation and the need for desorption.

[0068] S1.3, the sliding drain valve 2 slides to the upper part of the container 1, the water filling valve 3 descends, the flushing pump 9 is opened, the desorption liquid 8 is pumped into the container 1, and the directional phosphorus adsorption matrix packing 6 is soaked.

[0069] S1.4 After desorption is completed, the flushing pump 9 is connected to the external water filling structure through the pipeline. The flushing pump 9 is turned on and the sliding drain valve 2 is slid to the lower half of the container 1 for rapid flushing.

[0070] S1.5 and phosphorus are returned to the field along with the desorption solution 8, thus completing the reuse of irrigation water;

[0071] S2, Non-fertile water period

[0072] S2.1, the sliding drain valve 2 slides to the upper part of the container 1, the filling valve 3 rises, and normal drainage occurs.

[0073] Example 2

[0074] Same as Example 1, a precision control system and control method for farmland non-point source phosphorus based on enrichment-reuse.

[0075] It should be noted that, in this embodiment, the directional phosphorus adsorption matrix filler 6 includes lanthanum-based coated molecular spheres and lanthanum-based coated molecular bricks. One lanthanum-based coated molecular brick is disposed on each side of the lanthanum-based coated molecular spheres, and the volume ratio of lanthanum-based coated molecular spheres to lanthanum-based coated molecular bricks is 2:1.

[0076] The preparation method of the directional phosphorus adsorption matrix filler 6 in this embodiment includes the following steps:

[0077] Sa, prepare a 0.4 mol / L La(NO3)3·6H2O solution;

[0078] Sb. Zeolite molecular bricks and zeolite molecular balls are placed in the solution and stirred to mix them thoroughly. The solid-liquid ratio is 1 kg / L. Then, a NaOH solution with a solid-liquid ratio of 2 kg / L and a concentration of 1 mol / L is gradually added to treat the solution. After standing and soaking for 8 hours, the solution is taken out.

[0079] S5. Calcination in a muffle furnace at 200 ℃ for 4 h, followed by removal after cooling to room temperature, yields lanthanum-based coated molecular spheres and lanthanum-based coated molecular bricks, as shown below. Figure 3 (c) in the middle.

[0080] The components of desorption solution 8 include:

[0081] A mixed solution of 2% potassium chloride and 1% citric acid;

[0082] like Figure 3 As shown in (a), before desorption, based on the monitoring results of two actual rainfall events, the difference in phosphorus concentration before and after the monitoring system was calculated, and the average removal efficiency of phosphorus in the paddy field fertilizer water produced by rainfall was found to be 78.5%. After desorption, based on the monitoring results of two actual rainfall events, the difference in phosphorus concentration before and after the monitoring system was calculated, and the average removal efficiency of phosphorus in the paddy field fertilizer water produced by rainfall was found to be 53.82%.

[0083] It should be noted that the wireless data acquisition device 4 used in this embodiment is a LoRa wireless data acquisition device. When the phosphorus concentration identification sensor 5 detects that the phosphorus concentration exceeds the preset limit (set to 0.2 mg / L in this embodiment), the data is transmitted to the terminal through the wireless data acquisition device 4 to indicate adsorption saturation and the need for desorption. The sliding drain valve 2 and the water filling valve 3 are closed, and the flushing pump 9 is turned on, allowing the desorption liquid 8 (2% KCl solution) in the desorption liquid container 7 to flow into the upper space of the container 1 and soak the directional phosphorus adsorption matrix packing 6. Figure 3 As shown in (b), with the progression of desorption time, phased sampling and monitoring revealed that the total phosphorus concentrations in the desorbate 8 were 3.8 mg / L (10 min), 3.0 mg / L (30 min), 1.5 mg / L (60 min), 2.5 mg / L (90 min), 3.7 mg / L (120 min), and 3.1 mg / L (120 min). These data indicate that the maximum concentration occurred at 10 min, meaning that 10 min is the optimal desorption time for the 2% KCl + 1% citric acid mixed solution. After desorption, the flushing pump 9 was connected to an external water filling structure via a pipeline, and the flushing pump 9 was turned on (flow rate adjusted to 100 m). 3 / h), the sliding drain valve 2 slides to the lower half of the container 1, and the desorbed liquid 8 is quickly flushed with irrigation water. The phosphorus is returned to the field along with the desorbed liquid 8, thus completing the irrigation water reuse.

[0084] Example 3

[0085] Same as Example 1, a precision control system and control method for farmland non-point source phosphorus based on enrichment-reuse.

[0086] The preparation method of the directional phosphorus adsorption matrix filler 6 in this embodiment includes the following steps:

[0087] Sa, prepare a 0.4 mol / L La(NO3)3·6H2O solution, and simultaneously add a 0.4 mol / L Fe(NO3)3·9H2O solution;

[0088] Sb. Zeolite molecular bricks and zeolite molecular balls are placed in the solution and stirred to mix them thoroughly. The solid-liquid ratio is 0.1 kg / L. Then, a NaOH solution with a solid-liquid ratio of 0.1 kg / L and a concentration of 1 mol / L is gradually added to treat the solution. After standing and soaking for 12 h, the solution is taken out.

[0089] Sc, calcined in a muffle furnace at 300 ℃ for 6 h, and removed after cooling to room temperature, yielded lanthanum-based coated molecular spheres and lanthanum-based coated molecular bricks, such as Figure 4 As shown in (c) in the figure.

[0090] The components of desorption solution 8 include:

[0091] A mixed solution made of 2% potassium chloride and 0.5% citric acid by mass.

[0092] like Figure 4 As shown in (a), based on the monitoring results of two actual rainfall events, the average removal efficiency of phosphorus in the paddy field fertilizer water generated by precipitation was 55.26% by calculating the difference in phosphorus concentration before and after the monitoring system.

[0093] like Figure 4 As shown in (b), when the phosphorus concentration identification sensor 5 detects that the phosphorus concentration exceeds the preset limit (set to 0.2 mg / L in this embodiment), the data is transmitted to the terminal via the wireless data acquisition device 4, indicating adsorption saturation and the need for desorption. The sliding drain valve 2 and the water filling valve 3 are closed, and the built-in valve flushing pump 9 is opened, allowing the desorption solution 8 (2% KCl + 1% citric acid solution) in the desorption solution container 7 to flow into the upper space of the container 1 and soak the directional phosphorus adsorption matrix packing 6. As the desorption time progresses, phased sampling and monitoring are performed, and the total phosphorus in the desorption solution 8 is found to be 7.2 mg / L (10 min), 4.3 mg / L (30 min), 1.9 mg / L (60 min), 4.2 mg / L (90 min), 5.1 mg / L (120 min), and 4.8 mg / L (120 min), respectively. This indicates that 120 min is the optimal desorption time for the 2% KCl + 0.5% citric acid solution. After desorption is completed, flushing pump 9 is connected to the external water filling structure through a pipeline, and flushing pump 9 is turned on (flow rate adjusted to 180 m). 3 / h), the sliding drain valve 2 slides to the lower half of the container 1, and the desorbed liquid 8 is quickly flushed with irrigation water. After the desorbed liquid 8 is flushed, the sliding drain valve 2 is closed at the same time to prevent backflow. The phosphorus element is flushed into the aquatic plants and paddy fields with the desorbed liquid 8 and is absorbed in sequence, thus completing the reuse of irrigation water.

[0094] After desorption, based on the monitoring results of two actual rainfall events, the difference in phosphorus concentration before and after the monitoring system was calculated, and the average removal efficiency of phosphorus in the paddy field fertilizer water generated by precipitation was found to be 51.73%.

[0095] It should be noted that, unlike the efficiency of idealized laboratory-like purification experiments, when applying purification systems in actual farmland, it is very difficult to improve the purification efficiency of phosphorus due to factors such as the area of ​​pollution and the uncontrollable outdoor environment. Therefore, the improvement effect of this invention has been very significant in actual application.

[0096] In summary, the technical solution of this invention can effectively and rapidly remove phosphorus pollution from emergency drainage during the fertilization and irrigation period of farmland, and effectively avoids the damage to substrate materials caused by conventional drainage and rainwater, thus achieving precise treatment of agricultural non-point source phosphorus pollution. Simultaneously, it enables multiple rounds of in-situ reuse of the substrate filler, improving the material's efficiency, and the desorption solution 8 has high desorption efficiency, no toxic side effects on plants / crops, and improves nutrient utilization efficiency.

[0097] The technical scope of this invention is not limited to the content described above. Those skilled in the art can make various modifications and variations to the above embodiments without departing from the technical concept of this invention, and all such modifications and variations should fall within the protection scope of this invention.

Claims

1. A control method of a farmland non-point source phosphorus pollution precise treatment system based on enrichment-recycling, characterized in that, The system comprises a water control unit, a purification unit, a desorption unit and a power supply unit. The purification unit is installed in the water control unit, and the water control unit is connected with the desorption unit. The water control unit is used for water flow control of the system. The purification unit is used for purifying farmland non-point source pollution water, and comprises a directional phosphorus adsorption substrate filler, which is a lanthanum-based coated molecular ball and a lanthanum-based coated molecular brick. The desorption unit is used for desorption when the phosphorus adsorption capacity of the purification unit is saturated. The power supply unit is used for power supply of the system. The directional phosphorus adsorption substrate filler comprises the lanthanum-based coated molecular ball and the lanthanum-based coated molecular brick, the lanthanum-based coated molecular ball is provided with the lanthanum-based coated molecular brick on both sides, and the total volume ratio of the lanthanum-based coated molecular ball to the lanthanum-based coated molecular brick is 2:

1. The preparation method of the directional phosphorus adsorption substrate filler comprises the following steps. The preparation method of the directional phosphorus adsorption substrate filler comprises the following steps. Sb, the zeolite molecular brick and the zeolite molecular ball are put into the solution and stirred to mix them fully, the solid-liquid ratio is 0.1-1 kg / L, then a 1 mol / L NaOH solution with a solid-liquid ratio of 0.1-2 kg / L is gradually added to treat the solution, and the solution is taken out after standing and soaking for 8-12 h; Sc, the lanthanum-based coated molecular ball and the lanthanum-based coated molecular brick are obtained by calcining in a muffle furnace at 200-300 ℃ for 4-6 h and taking them out after the temperature decreases to room temperature; The control method comprises the following steps. S1, fertilizer water period S1.1, the water control unit is operated, the drainage valve is slid to the lower half of the container, the irrigation valve is lifted, the water flow generates an upward flow, enters the purification unit, the directional phosphorus adsorption substrate filler quickly adsorbs phosphorus in the drainage water, and the fertilizer water purification is completed; S1.2, when the phosphorus concentration recognition sensor recognizes that the phosphorus concentration exceeds the limit value, data is transmitted to the terminal through the wireless data collector to indicate that the adsorption is saturated and desorption is needed; S1.3, the drainage valve is slid to the upper half of the container, the irrigation valve is lowered, the flushing pump is opened, the desorption liquid is pumped into the container, and the directional phosphorus adsorption substrate filler is soaked; S1.4, after the desorption is completed, the flushing pump is connected to the external irrigation structure through the pipeline, the flushing pump is opened, the drainage valve is slid to the lower half of the container, and rapid flushing is performed; S1.5, phosphorus returns to the field with the desorption liquid, and irrigation reuse is completed; S2, non-fertilizer water period S2.1, the drainage valve is slid to the upper half of the container, the irrigation valve is lifted, and normal drainage is performed; The desorption liquid comprises the following components. Wood vinegar volume fraction is 90%-98%, and pH value is 3.5-5 Potassium chloride solution mass fraction is 2% Citric acid solution mass fraction is 0.5%-1%. ​ ​ 2.The control method of the farmland non-point source phosphorus pollution precise treatment system based on the enrichment-reuse according to claim 1, characterized in that, The water control unit comprises a container, a sliding drainage valve, a water filling valve, a wireless data collector and a phosphorus concentration identification sensor, the sliding drainage valve and the water filling valve are installed at the front and rear ends of the water flow direction of the container, the wireless data collector is arranged outside the water filling valve, the lower end is connected to the phosphorus concentration identification sensor, and the phosphorus concentration identification sensor is inserted into the drainage. 3.The control method of the farmland non-point source phosphorus pollution precise treatment system based on the enrichment-reuse according to claim 2, characterized in that, The container is internally provided with a partition plate, the partition plate divides the container into an upper half and a lower half, and the volume ratio of the upper half to the lower half ranges from 1:1 to 2:1, the directional phosphorus absorption matrix filler is arranged in the upper half of the container, and the partition plate position and the bottom of the container are both provided with a clamping point for sliding limiting of the sliding drainage valve, and the area ratio of the sliding drainage valve to the water filling valve is 1:

2.

4. The control method of the farmland non-point source phosphorus pollution precise treatment system based on enrichment-reuse according to claim 3, characterized in that, The desorption unit comprises a desorption liquid container, desorption liquid and a flushing pump, the desorption liquid container is filled with desorption liquid and is connected to the flushing pump, and the flushing pump is connected to the outside of the water filling valve through a pipeline. 5.The control method of the farmland non-point source phosphorus pollution precise treatment system based on the enrichment-reuse according to claim 2, characterized in that, The energy supply unit adopts a solar cell panel, the solar cell panel is installed above the container, and the wireless data collector adopts an LORA wireless data collector. 6.The control method of the farmland non-point source phosphorus pollution precise treatment system based on the enrichment-reuse according to claim 4, characterized in that, The flushing pump is a submersible pump capable of controlling water flow rate, with a rated flow rate of 100-180 m 3 / h.

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