Regeneration water irrigation system based on ultraviolet peroxo organic acid combination and water treatment method

Abstract

The application provides a recycled water irrigation system based on ultraviolet peroxo organic acid combination and a water treatment method. The system comprises a shell, a POA dosing tank and a control unit. The lower part of the shell is provided with a water inlet, and the upper part is provided with a water outlet. The water inlet is provided with a lifting pump. A glass liner is arranged in the shell. The interior of the glass liner is divided into a first chamber, a second chamber and a third chamber which are sequentially communicated by a baffle. A grid is arranged in the first chamber. The inner wall of the first chamber is provided with spiral flow guide lines. An ultraviolet light intensity sensor is arranged in the second chamber. The top of the third chamber is provided with a UV-Vis spectrometer with a built-in quartz cuvette. A nozzle, a stirring mechanism, a spiral mixer and a glass electrode pH sensor are arranged in the third chamber. The bottom of the third chamber is provided with an ultraviolet lamp. The system solves the safety and applicability problems of direct irrigation of recycled water through the synergistic effect of ultraviolet irradiation and oxidation.

Description

Technical Field

[0001] This invention relates to the field of advanced treatment and application of reclaimed water, and in particular to a reclaimed water irrigation system and water treatment method based on a combination of ultraviolet light and organic acids. Background Technology

[0002] Wastewater reuse is of great significance in alleviating water shortages. Wastewater reuse refers to the process of treating urban wastewater to remove pollutants and then reusing it for various purposes such as urban greening and industrial water use. Urban greening water accounts for 10% to 30% of the total urban water consumption, and using reclaimed water for greening irrigation can effectively reduce the consumption of clean water resources.

[0003] Traditional reclaimed water irrigation processes, such as chlorination disinfection, often struggle to effectively remove and control new pollutants, particularly chlorine-resistant bacteria, in reclaimed water. Furthermore, they suffer from problems such as highly toxic disinfection byproducts and long treatment times, impacting treatment efficiency and limiting the application scope of reclaimed water. Single technologies like ultraviolet (UV) disinfection are inefficient and energy-intensive. Advanced oxidation processes based on ultraviolet irradiation (UV-AOPs) have seen widespread research and application in water treatment in recent years. This process activates oxidant precursors through UV irradiation to produce active species, achieving highly efficient pollutant removal. Peroxyorganic acids (POAs), as environmentally friendly disinfectants, possess high bactericidal capabilities, produce few disinfection byproducts, and are gentle on plants. The UV / POA system, combining POA with UV light, demonstrates advantages in both treatment efficiency and environmental friendliness, showing promising development and application prospects. Summary of the Invention

[0004] To address the above technical problems, this invention discloses a reclaimed water irrigation system and water treatment method based on ultraviolet peroxide organic acid (POA) combination. It can automatically control the POA dosage, effectively reduce agent loss, achieve good treatment effect, and is gentle on plants. It effectively solves the problems of poor treatment effect and high toxicity of disinfection by-products when using reclaimed water for plant irrigation.

[0005] The technical solution adopted by this invention is as follows:

[0006] A reclaimed water irrigation system based on ultraviolet peroxide organic acid (UV-POA) combination includes a shell, a POA dosing tank, and a control unit. The shell has an inlet at the bottom and an outlet at the top. The inlet is equipped with a booster pump. The outlet is connected to a neutralization tank, and the neutralization tank is connected to an irrigation module.

[0007] The shell contains a glass liner, and the interior of the glass liner is divided into a first chamber, a second chamber, and a third chamber that are connected in sequence by a baffle; the water inlet is connected to the first chamber, and the third chamber is connected to the water outlet;

[0008] The first chamber is equipped with a filter grid, and the inner wall of the first chamber is equipped with spiral guide patterns;

[0009] The second chamber is equipped with an ultraviolet light intensity sensor;

[0010] Activated carbon is laid in the connecting pipe between the second and third chambers;

[0011] The top of the third chamber is equipped with a UV-Vis spectrometer with a built-in quartz cuvette. The third chamber contains a nozzle, a stirring mechanism, a spiral mixer, and a glass electrode pH sensor. The bottom of the third chamber is equipped with an ultraviolet lamp. The nozzle is located below the water inlet of the third chamber and faces into the third chamber. The ultraviolet lamp is electrically connected to an ultraviolet light intensity sensor.

[0012] The POA dosing tank is connected to the nozzle via a POA metering pump.

[0013] The control unit is electrically connected to the booster pump, ultraviolet lamp, ultraviolet light intensity sensor, UV-Vis (ultraviolet-visible spectrophotometer), and POA reagent metering pump, respectively.

[0014] The control unit incorporates a standard spectral database, a multivariate correction model, and an intelligent decision-making module based on a Bayesian optimization algorithm. The standard spectral database pre-stores characteristic spectral data of major pollutants in the reclaimed water. The multivariate correction model is established based on partial least squares or principal component regression algorithms and is used to invert the real-time concentration of pollutants from the absorbance feedback of the UV-Vis spectrometer. The intelligent decision-making module takes ultraviolet light intensity and oxidant dosage as input parameters X, and treatment effect and operating cost as output objectives Y. It fits the operating parameters through a Gaussian process GP substitution model and outputs the optimal configuration, dynamically optimizing the control of the intensity of the ultraviolet low-pressure mercury lamp and the dosage of the POA reagent metering pump.

[0015] The aforementioned technical solution utilizes a glass inner tank, which offers good UV transmittance, ensuring uniform UV penetration into the water and activating peroxy organic acids to generate reactive hydroxyl radicals. Furthermore, the glass material's structure possesses chemical stability, making it suitable for the addition of strong oxidizing agents. The glass material does not release harmful heavy metals, plasticizers, or other pollutants. The second chamber receives the reclaimed water filtered from the first chamber and also pre-treats the core reaction in the third chamber. The UV intensity sensor is located in the second chamber, which serves as a transition and monitoring hub, allowing for early control of key UV process parameters (UV intensity). Additionally, placing the UV intensity sensor here allows for monitoring of the UV state before the water flows into the core reaction zone, preventing the failure of the subsequent UV-POA synergistic reaction in the third chamber due to abnormal light intensity (such as lamp aging), and more directly capturing the original light intensity of the lamps. If the sensor is placed in the third chamber, the oxidation reaction caused by the addition of POA reagent may be accompanied by weak light absorption or scattering, interfering with the accuracy of light intensity monitoring. However, the second chamber has no reagent added and can only pass filtered water, which can eliminate the interference of reagent on light intensity monitoring and accurately reflect the light intensity output of the lamp itself.

[0016] As a further improvement of the present invention, the inner wall of the first chamber is provided with spiral guide lines.

[0017] As a further improvement of the present invention, a vibration sensor and a pressure transmitter are provided in the connecting pipeline between the first chamber and the second chamber. The vibration sensor and pressure transmitter are electrically connected to a controller, which is electrically connected to the booster pump via an emergency stop circuit. The emergency stop circuit is equipped with an emergency stop button. Furthermore, the controller's logic is set such that when the real-time vibration value fed back by the vibration sensor is greater than a preset upper threshold, and the real-time pressure value fed back by the pressure transmitter is less than a preset lower threshold or greater than a preset upper threshold for a continuous period exceeding a preset delay time, the controller triggers an audible and visual alarm and cuts off the power supply to the booster pump. This is used to monitor pipeline blockage and pump operating status.

[0018] As a further improvement of the present invention, water guns are installed at the front and rear ends of the quartz cuvette, and the water guns are periodically activated to perform air-water mixing backwashing to remove the deposits on the surface of the cuvette.

[0019] As a further improvement of the present invention, the spiral mixer has a three-section structure with a spiral angle of 45°, which is used to make the water flow form a vortex to prolong the contact time between POA and ultraviolet light.

[0020] As a further improvement of the present invention, the third chamber is equipped with a glass electrode pH sensor, which is electrically connected to the control unit. The control unit controls the POA metering pump to start based on the information fed back by the glass electrode pH sensor, thereby controlling the dosage of POA and stabilizing the pH of the water at 6-8.

[0021] As a further improvement of the present invention, the control unit is also connected to a weather forecast data interface. The control unit stores local historical water quality data, meteorological data, and plant water requirement models. The control unit makes irrigation decisions based on weather forecast data: if the predicted probability and amount of rainfall in a specific future time exceed a set threshold, the planned irrigation task is canceled; if a strong wind warning is received, sprinkler irrigation is prohibited, and drip irrigation is switched or irrigation is stopped.

[0022] As a further improvement of the present invention, the control unit dynamically adjusts the working modes of UV disinfection and POA oxidation based on the influent organic matter concentration data detected by the UV-Vis spectrometer using a Bayesian optimization algorithm. When the influent organic matter concentration is below the lower limit threshold, a mode of UV disinfection as the primary method and POA addition as a secondary method is adopted; when the influent organic matter concentration is above the upper limit threshold, the POA addition concentration is automatically increased. The lower and upper limits can be determined using TOC as the criterion. According to GB / T 25499-2010 "Irrigation Water Quality Indicators," a TOC of less than 1000 mg / L is considered normal. The upper limit threshold can be set to TOC 1000 mg / L. UV disinfection ensures the dominant disinfection effect through "light intensity monitoring - automatic adjustment - aging warning," while POA disinfection achieves auxiliary oxidation through "precise adjustment of metering pumps + pH synergy." Both are linked through a Bayesian optimization algorithm and multiple sensors to form a closed loop of "achieving the desired effect and minimizing cost."

[0023] As a further improvement of the present invention, the plant water requirement model is established based on the Penman formula. The input variables X of the model include temperature, humidity, wind speed and solar radiation intensity, and the output variable Y is the plant evapotranspiration. The formula is Y = k1×solar radiation intensity + k2×temperature + k3×humidity + k4×wind speed, where k1, k2, k3, and k4 are empirical coefficients obtained by fitting local historical data.

[0024] As a further improvement of the present invention, the Bayesian optimization algorithm fits the operating parameters using a Gaussian process (GP) substitution model. The input parameters are X = [UV light intensity, oxidant dosage], and the output objective is Y = [treatment effect, operating cost]. A GP model is established and follows a Gaussian process f(X) ~ GP(μ(X), k(X,X′)); where μ(X) is the mean function and k(X,X′) is the covariance function. Based on the GP model, the optimal parameter configuration and the most worthwhile parameter points are explored using an acquisition function (expected improvement in EI). The objective function f(μ(X), k(X,X′)) is calculated at a certain point m. The expected improvement of EI(X) relative to the optimal solution f*(X) is E(max(m,f*(X)-f(X))). Within the feasible region, the parameter point xn that maximizes EI(X) is found. The parameter xn is sent to the execution unit, and the actual running cost yn under this parameter is collected. The data pair (xn,yn) is expanded to the historical database. The above steps are repeated to continuously update the GP model and explore new parameter points until the preset number of iterations is reached or the cost improvement of consecutive iterations is lower than the threshold. Finally, the optimal combination of running parameters (Xn,Yn) is output to complete the optimization loop.

[0025] As a further improvement of the present invention, the neutralization tank is equipped with a sodium hydroxide solution addition module to adjust the pH of the effluent to 6-8 to ensure complete decomposition of POA; the irrigation module is equipped with a clean water flushing control module to flush the pipes after irrigation.

[0026] As a further improvement of the present invention, the filter screen includes a coarse screen and a fine screen, which are arranged sequentially along the water flow direction. Further, the spacing between the coarse screens is greater than 50 mm, and the spacing between the fine screens is no greater than 10 mm. The spacing between the coarse and fine screens can be flexibly selected according to the actual particle size distribution of impurities in the influent.

[0027] As a further improvement of the present invention, the connecting pipe between the POA metering pump and the POA automatic dosing tank is made of PVDF-lined stainless steel pipe.

[0028] As a further improvement of the present invention, the POA drug metering pump is a diaphragm metering pump, and its diaphragm material is polytetrafluoroethylene.

[0029] As a further improvement of the present invention, the outer wall of the glass liner is provided with a touch screen, which is connected to the control unit to display water quality parameters in real time.

[0030] As a further improvement of the present invention, the housing is made of stainless steel, and a plastic cover is provided on the top of the housing, with an exhaust hole on the plastic cover.

[0031] This invention also discloses a method for treating reclaimed water based on the above-described reclaimed water irrigation system using a combination of ultraviolet light and organic acids, comprising the following steps:

[0032] Step S1: The effluent from the secondary sedimentation tank is pumped to the first chamber by a lift pump, filtered by a filter screen, and then enters the second chamber.

[0033] In step S2, water flows through the second chamber after impurities are removed by the activated carbon adsorption layer. Simultaneously, the controller monitors the equipment's operating status based on data from vibration sensors and pressure transmitters, and identifies pipe blockages and pump malfunctions through water flow pressure. The control unit monitors the light intensity distribution and lamp aging degree based on data from the ultraviolet light intensity sensor.

[0034] In step S3, water flows into the third chamber, and the UV-Vis spectrometer monitors the water quality in real time. The control unit calculates the pollutant concentration and dynamically adjusts the intensity of the ultraviolet low-pressure mercury lamp and the dosage of POA agent based on real-time water quality and Bayesian optimization algorithm to achieve efficient disinfection and oxidation.

[0035] Step S4: The treated water enters the neutralization tank and is then used for irrigation of the greenery.

[0036] As a further improvement of the present invention, in step S3, when the inverted organic matter concentration is continuously lower than the preset threshold, the intelligent decision-making module prioritizes exploring the parameter space of "high ultraviolet light intensity and low POA dosage" so that the system operates in the mode of "ultraviolet as the main component and POA as the auxiliary component".

[0037] As a further improvement of the present invention, step S2 also includes data input and prediction, inputting historical water quality data, plant water requirements, weather forecast information, rainfall and plant greening irrigation needs into the control unit to realize the advance adjustment of operating parameters.

[0038] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0039] The technical solution of this invention combines ultraviolet irradiation disinfection technology and peroxy organic acid oxidation technology to form a combined treatment system based on UV and POA. The hydroxyl radicals (·OH) generated by the reaction have strong oxidizing properties and can efficiently decompose pollutants, avoiding their toxic effects on plant roots and leaves. Simultaneously, this invention incorporates Bayesian algorithms and statistical methods to automatically control the POA dosage. When the influent pollutant concentration is low, it automatically switches to a "UV-based, POA-assisted" disinfection mode, resulting in good treatment effect, gentleness on plants, and effective reduction of pesticide consumption, thus saving economic costs. Through the synergistic effect of UV irradiation and oxidation, the safety and applicability issues of direct irrigation with reclaimed water are solved, ensuring healthy plant growth and soil ecological stability while reducing potential risks to the surrounding environment and residents. It also provides an economically feasible technical path for the resource utilization of reclaimed water, particularly suitable for the greening irrigation needs of urban parks, roadside green belts, and residential areas.

[0040] Furthermore, the technical solution of this invention, through the input of historical water quality data, rainfall, actual greening irrigation needs of plants, and real-time weather forecast updates, enables advance adjustments to emergencies, making it more closely aligned with actual conditions. This effectively solves problems such as the irreversible damage to plants caused by disinfection byproducts after reclaimed water treatment and the impact of unstable water quality parameters on the balance of soil microbial communities. Attached Figure Description

[0041] Figure 1 This is a schematic diagram of a reclaimed water irrigation system based on ultraviolet peroxy organic acid combined according to an embodiment of the present invention.

[0042] Figure 2 This is a standard curve of humic acid at different concentrations according to the present invention.

[0043] The reference numerals in the figures include:

[0044] 1-Housing, 2-Cover plate, 3-Glass inner liner, 4-Lift pump, 5-Vibration sensor, 6-Pressure transmitter, 7-Transparent observation window, 8-Ultraviolet light intensity sensor, 9-UV-Vis spectrometer, 10-Miniature touch screen, 11-Ultraviolet low-pressure mercury lamp, 12-POA reagent metering pump, 13-POA automatic dosing tank, 14-Bolt, 15-Inlet, 16-Valve, 17-Outlet, 18-POA inlet pipe, 19-Exhaust port, 20-Sealing gasket, 21-Inspection port, 22-Stainless steel pressure strip, 23-Coarse screen, 24-Fine screen, 25-Cable, 26-Nozzle, 27-Water gun, 28-Quartz cuvette, 29-Glass electrode pH sensor, 30-Spiral mixer, 31-Neutralization tank, 32-Spray head. Detailed Implementation

[0045] The preferred embodiments of the present invention will be described in further detail below.

[0046] like Figure 1 As shown, a reclaimed water irrigation system based on a combined system of UV (ultraviolet) irradiation and POA (peroxyorganic acid) oxidation includes a stainless steel shell 1, a plastic cover 2, a glass inner tank 3, a reclaimed water booster pump 4, a vibration sensor 5, a pressure transmitter 6, a transparent observation window 7, an ultraviolet light intensity sensor 8, a UV-Vis spectrometer 9, a miniature touch screen 10, an ultraviolet low-pressure mercury lamp 11, a POA reagent metering pump 12, a POA automatic dosing tank 13, and a control unit. The plastic cover 2 is located on top of the shell 1, and the glass inner tank 3 is located inside the shell 1. The shell 1 has an inlet 15 at the bottom, an outlet 17 at the top, and an exhaust port 19 at the top. The inlet 15 is connected to the booster pump 4 (a stainless steel centrifugal pump); the outlet 17 is connected to a neutralization tank 31, and the neutralization tank 31 is connected to the irrigation module.

[0047] The glass inner liner 3 is divided into three chambers by baffles, namely the first chamber, the second chamber, and the third chamber. The first chamber is equipped with a coarse screen 23 and a fine screen 24. Reclaimed water is lifted from the secondary sedimentation tank, further filtered, and then transported to the second chamber. Furthermore, the spacing of the coarse screen 23 is greater than 50 mm, and the spacing of the fine screen 24 is no greater than 10 mm. The spacing of the coarse screen 23 and the fine screen 24 can be flexibly selected according to the actual particle size distribution of impurities in the influent.

[0048] A vibration sensor 5 and a pressure transmitter 6 are connected to the outside of the second chamber. These are electrically connected to a PLC controller, which uses the signals from the sensors to identify pipe blockages and pump malfunctions. An ultraviolet light intensity sensor 8 is installed inside the second chamber and connected to a low-pressure ultraviolet mercury lamp 11 located in the third chamber. This sensor monitors the light intensity distribution and lamp aging, facilitating timely replacement of the lamp. Activated carbon is laid in the connecting pipe between the second and third chambers to remove minute impurities from the water.

[0049] The top of the third chamber is equipped with a UV-Vis spectrometer 9 containing a built-in quartz cuvette 28. The third chamber also contains a nozzle 26, a stirring mechanism, a spiral mixer 30, and a glass electrode pH sensor 29. A low-pressure ultraviolet mercury lamp 11 is located at the bottom of the third chamber. The nozzle 26 is positioned below the inlet 15 of the third chamber and faces inwards. The glass electrode pH sensor 29 is electrically connected to the POA reagent metering pump 12.

[0050] The shell 1 is equipped with a miniature touch screen 10, which displays water quality parameters in real time. It uses UV-Vis to invert pollutant concentration and adopts a Bayesian optimization algorithm. When the organic matter concentration in the influent is lower than the lower limit threshold of organic matter concentration, it automatically switches to a disinfection mode of "UV as the main method and POA as the auxiliary method" to reduce the consumption of disinfectant.

[0051] The POA dosing tank is connected to the POA inlet pipe 18 via the POA metering pump 12, and the POA inlet pipe 18 is connected to the nozzle 26; the control unit is electrically connected to the booster pump 4, the ultraviolet low-pressure mercury lamp 11, the ultraviolet light intensity sensor 8, the UV-Vis spectrometer 9, and the POA metering pump 12.

[0052] The housing 1 is equipped with a transparent observation window 7 and an inspection port 21. The inlet 15 is located in the lower part of the housing 1 and is directly connected to a stainless steel centrifugal pump for lifting and transporting water from the secondary sedimentation tank. A valve 16 is installed on the pipe containing the inlet 15 to control the inflow and outflow of water. The outlet 17 is located in the upper part of the housing 1 and is used to discharge the treated reclaimed water, ensuring proper water flow within the system. The POA inlet pipe 18 is also located in the lower part of the housing 1 and is used to transport peroxy organic acid into the housing for combined action with ultraviolet light. The exhaust port 19 is located in the upper part of the housing 1 and is used to discharge gases generated within the housing due to reactions or other factors, maintaining stable internal system pressure. A sealing gasket 20 is provided between the housing 1 and the plastic cover 2 to prevent leakage of treated water and gas, ensuring the safety and operational stability of the equipment. Furthermore, a transparent observation window 7 is provided on the housing 1 to facilitate viewing the internal water flow, component working status, etc. during equipment operation. An inspection port 21 is also provided to facilitate regular cleaning and maintenance of the equipment's interior, replacement of damaged parts and aging lamps.

[0053] The plastic cover plate 2 includes a cover plate body, bolts 14, and a stainless steel pressure strip 22. The cover plate body is typically made of a composite structure of PC (polycarbonate) and PMMA (polymethyl methacrylate). The outer PC layer provides impact resistance, the middle PMMA layer enhances durability, and the inner PC layer further improves structural stability. This combination can withstand long-term ultraviolet radiation and resist the strong oxidizing properties of POA. Silicone sealing rings are embedded at the edges of the cover plate body and at the connection with the equipment body, and are fixed by slots or pressure strips to ensure that corrosive media such as POA solutions do not leak out. At the same time, the cover plate body is fastened with bolts 14, and together with the stainless steel pressure strip 22, the sealing pressure is enhanced to prevent the cover plate from shifting due to internal air pressure fluctuations.

[0054] The glass inner liner 3 is coated with an anti-scaling coating. The first chamber of the glass inner liner serves as a pretreatment unit, requiring a grid to achieve initial solid-liquid separation and provide qualified influent for subsequent deep treatment.

[0055] The inner wall of the first chamber is provided with spiral guide patterns, which creates a weak vortex in the water flow, promoting the aggregation of suspended impurities towards the coarse screen 23 and fine screen 24 for removal. The second chamber serves as a transfer station, realizing light intensity monitoring and aging early warning. One set of ultraviolet light intensity sensors 8 are installed at the top, middle and bottom of the second chamber, and led out through cable 25 and connected to the third chamber to monitor the light intensity distribution in real time. The third chamber serves as the core processing unit, integrating real-time water quality monitoring, intelligent control, deep adsorption and precise dosing functions. A stainless steel nozzle 26 is installed below the inlet 15 of the third chamber, using gas-liquid mixing atomization to form POA solution droplets, which fully contact the water flow. Downstream of the nozzle 26, a three-stage spiral mixer 30 (spiral angle 45°) is installed to create a vortex in the water flow, extending the contact time between POA and ultraviolet light. An independent stainless steel sealed chamber is installed at the top of the third chamber, housing a built-in UV-Vis spectrometer 9. Real-time online analysis of water samples and detection of contaminant concentrations are achieved via a quartz cuvette 28. Water guns 27 are installed at the front and rear ends of the quartz cuvette 28, automatically initiating hourly air-water backwashing to remove organic matter and scale adhering to its surface, ensuring accurate light signal transmission. A miniature touchscreen 10 is installed on the outer wall of the housing 1, displaying real-time water quality parameters, dynamic curves of POA dosage, and equipment operating status, supporting local parameter settings and remote VPN control. A glass electrode pH sensor 29 is installed at the outlet of the third chamber to adjust the dosage of the POA metering pump 12, stabilizing the pH within the range of 6-8 to prevent damage to plants from excessive acidity or alkalinity. The automatic POA dosing tank 13 is equipped with an automatic replenishment interface. The POA inlet pipe 18 uses a PVDF-lined stainless steel pipe, and all valves are fully fluorine-lined to ensure long-term stable system operation. Three 254nm ultraviolet low-pressure mercury lamps 11 are installed in parallel at the end of the third chamber. They are isolated from the water by a quartz sleeve. The lamps are spaced 10cm apart, and the lamp supports are made of stainless steel and sprayed with an anti-POA corrosion coating.

[0056] After treatment, the water flows into neutralization tank 31. The outlet of neutralization tank 31 is connected to sprinkler head 32 or dripper head for irrigation of different types of plants. After irrigation, the clean water flushing program on the touch screen is activated to prevent POA decomposition products from accumulating in the pipes.

[0057] To achieve real-time monitoring and intelligent control of the treatment effect, this invention introduces online ultraviolet-visible spectroscopy (UV-Vis) monitoring technology. The control unit pre-stores a standard spectral database of major pollutants in the reclaimed water and a multivariate correction model based on algorithms such as partial least squares or principal component regression. Through preliminary experiments, the characteristic absorbance values ​​of common pollutants and recalcitrant organic matter in the reclaimed water at different concentrations are correlated with the actual concentration values ​​measured by standard methods, thereby establishing an absorbance-pollutant concentration standard curve, for example... Figure 2 The standard curves of humic acid at different concentrations shown are imported into a UV-Vis spectrometer and compared with standard spectral curves in the database. Through model calculations, the real-time concentration values ​​of target pollutants in the water can be quickly and accurately determined.

[0058] To improve the economic cost of the system under different influent conditions, this invention introduces an intelligent decision-making and control module based on a Bayesian optimization algorithm, which is built into the control unit. This module can automatically switch the operating mode of the dominant technology based on real-time changes in water quality. Based on extensive data from previous operations, the intelligent decision-making and control module uses influent organic matter concentration, removal rate, and energy and chemical consumption costs as key inputs. It fits the operating parameters using a Gaussian process (GP) substitution model: X = [UV light intensity, oxidant dosage], Y = [treatment effect, operating cost], establishing a GP model that follows a Gaussian process f(X) ~ GP(μ(X), k(X,X′)). Here, μ(X) is the mean function, usually a constant; k(X,X′) is the covariance function, used to measure the similarity between X and X′. Based on the GP model, the optimal parameter configuration and the most worthwhile parameter points are explored using the acquisition function (expected improvement in EI). The expected improvement in the objective function f(X) relative to the optimal solution f*(X) at a certain point m is calculated as EI(X) = E(max(m, f*(X) - f(X))). Within the feasible region, the parameter point xn that maximizes EI(X) is found. The control system sends the xn parameter to the execution unit and collects the actual operating cost yn under this parameter, expanding the data pair (xn, yn) to the historical database. These steps are repeated, continuously updating the GP model and exploring new parameter points until a preset number of iterations is reached or the cost improvement of consecutive iterations falls below a threshold. Finally, the optimal combination of operating parameters (Xn, Yn) is output, completing the optimization loop. During system operation, when the decision model calculates that the concentration of organic matter in the influent is consistently lower than the preset concentration threshold based on the real-time absorbance value of the influent, the model determines that the current water quality is suitable for ultraviolet disinfection and sterilization as the main purpose. At this time, the Bayesian optimization algorithm will execute the steps of "defining optimization - exploring parameter space - outputting and executing the optimal solution".

[0059] Optimization is defined as follows: the objective function is to minimize the total operating cost of the system while ensuring that microbial indicators (such as total coliform count and fecal coliform count) meet the standards.

[0060] Parameter space exploration: Within the set threshold range, priority is given to exploring regions with "high UV light intensity and low oxidant dosage". UV light itself has direct disinfection capabilities, and when the organic matter concentration is low, the generated ·OH is sufficient to degrade trace pollutants, while avoiding the byproduct risks and reagent costs caused by adding excessive oxidant.

[0061] Output and execute the optimal solution: Through iterative calculation, the Bayesian optimization algorithm quickly finds a set of optimal operating parameters and the most economical dosing point. The central control unit then switches the system to a stable, high-efficiency disinfection mode of "primarily ultraviolet light, supplemented by power of air (POA)" based on these parameters.

[0062] Specifically, when the organic matter concentration is determined to be high (influent TOC consistently above 1000 mg / L), the system calculates the optimal increment using a Bayesian optimization algorithm. Simultaneously, the algorithm presets a safe upper limit for POA dosage (based on experiments on the mildness of POA on plants, approximately 20 mg / L, to avoid oxidative damage to plant roots from excessive organic acids). Even with extremely high organic matter concentrations, the increment will not cause the total dosage to exceed this limit, while triggering a slight increase in UV intensity to aid degradation through a synergistic effect and prevent excessive POA dosage. The metering pump controls the POA dosage flow rate through pulse frequency adjustment. After the algorithm calculates the POA increment, it is automatically converted into the pulse frequency increment of the metering pump. The UV-Vis spectrometer re-inverts the effluent organic matter concentration every 5 minutes. If TOC still exceeds 1000 mg / L, the algorithm recalculates the increment and sends it to the metering pump for adjustment; if TOC has dropped to the target value, the algorithm stops the increment, maintaining the current dosage to avoid waste.

[0063] It can also input historical water quality data, rainfall, and actual irrigation needs for plants, and set up a real-time weather forecast update system to allow for advance adjustments in response to emergencies. Activated carbon is laid in the connecting pipeline between the second and third chambers to adsorb any remaining micro-impurities in the reclaimed water. An external POA (Polytetrafluoroethylene) metering pump is connected; this is a diaphragm-type pump with a diaphragm made of polytetrafluoroethylene, which is resistant to strong oxidation and acids / alkalis. The POA metering pump is connected to an automatic POA dosing tank, which automatically and accurately adds POA to the reclaimed water, ensuring a complete oxidation reaction and preventing overdose while avoiding harm to the plants.

[0064] Furthermore, the multivariate correction model targets key pollutants affecting plant growth and soil ecology in reclaimed water irrigation scenarios. It establishes a standard spectral database by experimentally collecting their characteristic absorption spectra in the UV-Vis spectral range (200-800 nm). A UV-Vis spectrometer is used to collect the absorbance of samples across the entire wavelength range, focusing on extracting the absorbance values ​​corresponding to the characteristic absorption peak wavelengths of the target pollutants. The actual concentration of the target pollutants in the same batch of samples is determined using national standard methods to ensure data accuracy. A quantitative correlation model of "absorbance-pollutant concentration" is established using the absorbance matrix at multiple wavelengths as the independent variable and the pollutant concentration as the dependent variable. A UV-Vis spectrometer scans the water sample in a quartz cuvette across the entire wavelength range, collecting continuous absorbance data in the 200-800 nm range. The preset wavelengths and absorbance in the multivariate correction model are automatically extracted to form a real-time absorbance matrix for analysis, serving as input data for model calculation. Partial least squares or principal component regression algorithms are used to fit and compare the real-time absorbance with the "absorbance-concentration" correlation in the standard spectral database. The real-time pollutant concentration calculated by the model is synchronously transmitted to a miniature touchscreen outside the third chamber, displayed as real-time water quality parameters, and simultaneously uploaded to the system's central control unit. When the model inversion shows that the influent organic matter concentration is consistently below the preset threshold, the Bayesian optimization algorithm determines that the current water quality is suitable for a disinfection mode of "UV-based, POA-based," because the hydroxyl groups generated by UV light are sufficient to degrade trace pollutants, eliminating the need for excessive POA addition. If the model inversion shows that "organic matter concentration is above the threshold," the algorithm automatically increases the POA dosage, switching to an oxidation mode of "POA-based, UV-based," ensuring efficient pollutant removal. The pollutant concentration of the treated effluent calculated by the model inversion needs to be compared with the irrigation water quality index in GB / T 25499-2010 to verify whether the UV-POA combined treatment effect meets the standard. At the same time, the system will expand the data pair of "real-time absorbance - inverted concentration - actual treatment effect" to the historical database and periodically iterate and optimize the multivariate correction model to ensure the accuracy of concentration inversion during long-term operation.

[0065] The system of this invention can identify pipeline blockages and water pump malfunctions through a PLC logic controller; it can also automatically control the dosage of POA; and through a Bayesian optimization algorithm, it can automatically switch to a "primarily ultraviolet, supplemented by POA" disinfection mode when the concentration of pollutants in the influent is low, effectively reducing reagent consumption; moreover, it can update the system in real time based on input historical water quality data, rainfall, actual greening irrigation needs of plants, and weather forecasts, enabling advance adjustments for emergencies. It has advantages such as good treatment effect and gentleness on plants, effectively solving the problems of poor treatment effect and high toxicity of disinfection byproducts in the current application of treated reclaimed water for plant irrigation.

[0066] The reclaimed water treatment method used in the above-mentioned reclaimed water irrigation system includes the following steps:

[0067] First, the reclaimed water after being treated by the sludge-water separation in the secondary sedimentation tank is powered by the electrical energy generated by the stainless steel centrifugal pump. It flows through the spiral guide pattern on the inner wall of the first chamber through the pipeline, which makes the water flow form a weak vortex. This promotes the aggregation of suspended impurities towards the screen. First, the coarse screen filters out the large molecular suspended solids and other impurities in the reclaimed water, and then the fine screen removes the small suspended impurities that the coarse screen failed to intercept, further purifying the incoming water.

[0068] 2. A vibration sensor and a pressure transmitter are connected to the pipeline connecting the first and second chambers. The vibration sensor and pressure transmitter are connected to a programmable logic controller (PLC). The vibration sensor is directly fixed to the flange and pipe section of the pipeline connecting to the first chamber. The pressure transmitter is connected to the pipeline through a three-way ball valve. The output signal lines of the vibration sensor and pressure transmitter are connected to the corresponding channels of the PLC's analog input module. The PLC's digital output points are connected to the emergency stop circuit of the centrifugal pump motor control circuit, in series with the emergency stop button, using a "hard wire" connection to ensure reliable power-off when the PLC sends a signal. The PLC internally stores the following preset parameters: upper vibration threshold Vmax = 4.5 mm / s, lower pressure threshold Pmin = 0.3 MPa, upper pressure threshold Pmax = 0.8 MPa, and delay time T = 3 seconds.

[0069] When water flows through the first chamber, the PLC executes the following logic in a loop: (1) Read the vibration value (V) and pressure value (P) in real time; (2) Input the judgment condition: IF (V>Vmax) AND (P)<Pmin OR P> Pmax) THEN; If the condition is met for more than the delay time T, it is judged as abnormal; (3) PLC DO output point action: One output point drives the sound and light alarm, and the other output point is connected in series to the emergency stop circuit of the centrifugal pump motor control cabinet to cut off the contactor and stop the centrifugal pump. If the judgment condition is not met, the reclaimed water enters the second chamber. The second chamber is equipped with an ultraviolet light intensity sensor, which is connected to the ultraviolet low-pressure mercury lamp in the third chamber through a cable to monitor the light intensity distribution and the aging degree of the lamp tube. If the lamp tube is aged, the ultraviolet light intensity sensor will issue an alarm and stop working. The lamp tube will be replaced through the maintenance port; if normal, the reclaimed water enters the third chamber through the connecting pipeline.

[0070] 3. Activated carbon is laid in the connecting pipe between the second and third chambers to adsorb any remaining minute impurities in the reclaimed water. As water flows through the third chamber, the UV-Vis spectrometer and miniature touchscreen 10 are activated, displaying real-time water quality parameters, the dynamic curve of POA dosage, and equipment operating status. The absorbance reflects the pollutant concentration. Water guns are installed at both ends of the cuvettes, automatically starting an hourly air-water backwash to remove organic matter and scale from the cuvette surface, ensuring accurate light signal transmission. The POA metering pump and the automatic POA dosing tank are turned on. The POA solution in the automatic dosing tank passes through the POA metering pump and POA inlet pipe to the nozzle, which sprays the POA solution in droplets, ensuring full contact with the water flow. The glass electrode pH sensor is activated to control the POA metering pump dosage, stabilizing the pH within the range of 6-8.

[0071] The water flows through a three-stage spiral mixer at a 45° angle, creating a swirling flow that prolongs the contact time between the POA (Polyurethane Acid) and ultraviolet light. The control unit's Bayesian optimization algorithm activates, automatically switching to a "primarily ultraviolet, supplemented by POA" disinfection mode when the influent organic matter concentration falls below the lower limit threshold, reducing reagent consumption. When ultraviolet disinfection is insufficient to reduce the influent organic matter concentration, the POA concentration is automatically increased to achieve efficient oxidation and removal of pollutants.

[0072] Furthermore, the control unit pre-stores and compiles localized water quality monitoring data for a complete year, with the data acquisition frequency set to 1 hour per time. Recording the COD value of influent at different times reflects the total amount of oxidizable organic matter in the water. Excessive COD can lead to the proliferation of soil microorganisms after irrigation, potentially causing plant root diseases. Historical data should be used to clarify the seasonal fluctuation pattern of COD in local reclaimed water. TOC data should be stored in mg / L. TOC directly represents the total amount of organic carbon in the water and can accurately reflect the actual content of organic matter. Its historical trend can help determine the long-term stability of the organic matter removal process in reclaimed water. Turbidity should be measured using NTU. Excessive turbidity can clog soil pores around plant roots and affect water permeability. Historical data can be used to analyze abnormal increases in turbidity in different seasons. Colorimetric data should be stored in units of degrees measured by the platinum-cobalt standard colorimetric method. Excessive colorimetry may contain pigment-like organic matter, and long-term irrigation may lead to soil discoloration. Historical statistics can clarify the correlation threshold between colorimetry and plant growth. Conductivity directly reflects the ion concentration in the water. Excessive conductivity can lead to soil salinization and affect the water absorption capacity of plants. Historical data can help to delineate the safe range of irrigation water quality for different vegetation areas. The data statistics module will automatically analyze the above indicators and generate daily averages, weekly averages, monthly averages, and seasonal fluctuation curves, providing data support for subsequent adjustments to irrigation plans.

[0073] Meanwhile, a complete year of localized meteorological data is synchronously stored. The data sources include the meteorological sensors supporting the spectrometer and the shared data of local meteorological stations. The rainfall is collected in real time by a rain gauge, and the daily rainfall is recorded in mm. The statistical module will further calculate the monthly cumulative rainfall and the proportion of rainfall in the rainy season and dry season; the evaporation is measured by the evaporation pan method, and the daily water surface evaporation is recorded in mm / d. Combining with the temperature and wind speed data, the evaporation differences in different seasons are statistically analyzed; the daily maximum temperature, minimum temperature and daily average temperature are recorded in °C. The statistical module will generate a monthly average temperature curve to clarify the suitable temperature range for plant growth; the daily average relative humidity is recorded in relative humidity (%). Combining with the temperature data analysis, the influence of temperature and humidity coupling on plant transpiration is analyzed.

[0074] For different vegetation types and seasons, the actual irrigation volume data for a complete year is stored. The irrigation area is divided into tree areas (such as roadside trees, landscape trees), shrub areas (such as hedges, flowering shrubs), lawn areas and flower areas according to plant types. An independent flow monitoring device is set in each area, and the daily actual irrigation volume is recorded in m³ / d; the statistical module divides the seasons into spring (March - May), summer (June - August), autumn (September - November), and winter (December - February of the following year), and analyzes the water demand differences of different vegetation in each season; combining with the plant growth stages (such as germination stage, growth stage, flowering stage, dormancy stage), the changes in irrigation volume at different stages are marked.

[0075] To cope with the impact of weather changes on irrigation, the control unit uses an Ethernet interface to connect with local meteorological stations and meteorological service platforms, and can receive real-time weather forecast data for the next 七十二 hours, including rainfall probability, estimated rainfall, wind force level, temperature and humidity changes, solar radiation intensity, etc.; the weather forecast data is automatically updated once an hour to ensure that the system can obtain the latest weather dynamics in a timely manner; when receiving an extreme weather warning (such as heavy rain, strong wind, high temperature and drought), the system will trigger a warning prompt and start the irrigation plan adjustment process 三 to six hours in advance to avoid unreasonable irrigation caused by sudden weather changes.

[0076] It should be noted that there seems to be an error in the Chinese text where "七十二 hours" should be "72 hours" and "三 to six hours" should be "3 - 6 hours" in the English translation. Also, the Chinese text about "结合植物生长阶段(如发芽期、生长期、开花期、休眠期)标注不同阶段的浇灌量变化。" has some incorrect English grammar in the provided translation. The corrected translation should be: Combining with the plant growth stages (such as germination stage, growth stage, flowering stage, dormancy stage), mark the changes in irrigation volume at different stages.To accurately calculate plant water requirements, the control unit incorporates a plant water requirement model. Through correlation analysis between environmental factors and plant transpiration, it achieves scientific regulation of irrigation. Basic water requirement parameters for common local plants are pre-inputted, categorized by growth stage: a minimum water requirement threshold is set for germination plants to ensure sufficient moisture for seed germination; a suitable water requirement range is set for growing plants to meet their rapid growth needs; a higher water requirement threshold is set for flowering plants to ensure flower development; and a minimum water requirement is set for dormant plants to prevent waterlogging and root rot. Using core environmental factors influencing plant transpiration as input, an "environmental factor-evapotranspiration" prediction model was constructed. Four factors affecting plant transpiration and soil evaporation—temperature (°C), relative humidity (%), wind speed (m / s), and solar radiation intensity (W / m²)—were used as inputs. Increased temperature accelerates water evaporation, decreased humidity increases the transpiration rate, increased wind speed promotes water vapor diffusion, and solar radiation intensity directly provides the energy required for transpiration. The actual plant transpiration (mm / d) was used as the output. Evapotranspiration is a core indicator of plant water requirement and directly determines the amount of irrigation. The model adopted the Pengman method. A linear correlation model was constructed: Y = k1 × solar radiation intensity + k2 × temperature + k3 × humidity + k4 × wind speed. A total of 365 sets of input data were selected based on the daily average temperature, humidity, wind speed, and solar radiation intensity data for a complete year. Simultaneously, actual plant evapotranspiration data for the corresponding dates were collected, resulting in 365 sets of output data. The least squares method was used to perform linear regression analysis on the input and output data to fit the specific values ​​of k1, k2, k3, and k4. The fitted model was then validated to ensure that the relative error between the model's predicted values ​​and the measured values ​​was ≤10%, meeting the accuracy requirements for irrigation decision-making.

[0077] The system combines real-time weather forecast data to determine the applicability of the Penman formula and then implements differentiated irrigation decisions. When the weather forecast received by the system shows "probability of rainfall > 60% and expected rainfall > 5 mm within the next 12 hours", the application conditions of the Penman formula are determined to be invalid.

[0078] The Penman formula is based on a natural evapotranspiration environment without rainfall. However, rainfall directly replenishes soil moisture. Irrigation based on the evapotranspiration calculated by the formula would lead to excessive soil moisture, wasting reclaimed water resources and potentially causing root hypoxia and root rot in plants. In this case, the system immediately triggers an irrigation cancellation process: it retrieves the currently pending irrigation tasks; automatically generates an "irrigation cancellation instruction" and sends it to the irrigation execution unit; displays the cancellation reason on the UV-Vis spectrometer's touch interface and records the cancellation log for future traceability; if reclaimed water has been stored in advance, the system will simultaneously adjust the water storage plan to avoid water waste caused by overflowing storage tanks. When the system receives a strong wind warning signal (wind force ≥ 5 input in advance), it determines that the application conditions of the Penman formula are not valid. High wind speeds significantly alter the actual evapotranspiration environment, and sprinkler irrigation under strong wind conditions presents problems such as low water efficiency and the risk of disease transmission. At this time, the system will implement differentiated control based on the wind force level: when the wind force is level 5-6, irrigation methods such as sprinkler irrigation and micro-sprinkler irrigation that are prone to water droplet drift are prohibited, and the system will automatically switch to drip irrigation mode. Through drippers buried in the soil surface, reclaimed water will be slowly and accurately dripped into the vicinity of plant roots, unaffected by wind force and reducing water evaporation; when the wind force is level 7 or higher, all outdoor irrigation operations will be stopped, and after the wind force drops to a safe range (level 5 or lower), the evapotranspiration will be recalculated based on the Penman formula, and a new irrigation plan will be formulated; in addition, the system will record the process of adjusting the irrigation method under the strong wind warning and use historical data to statistically analyze the impact of strong wind weather on irrigation efficiency.

[0079] 4. The treated water flows into the neutralization tank, where 1%–2% sodium hydroxide solution is added to adjust the pH to 6–8 to ensure complete decomposition of POA. The neutralization tank is connected to the sprinklers and drippers. After irrigation, a clean water flushing process is initiated to prevent the accumulation of POA decomposition products in the pipes.

[0080] This embodiment is verified by experiments. The water quality parameters before and after treatment by this system are shown in Table 1 below:

[0081] Table 1

[0082]

[0083] It is evident that the water quality treated by this system has significantly improved, and it has solved the problems of irreversible damage to plants caused by disinfection byproducts after reclaimed water treatment and the impact of unstable water quality parameters on the balance of soil microbial communities. This not only ensures healthy plant growth and soil ecological stability, but also reduces potential risks to the surrounding environment and residents.

[0084] The above description, in conjunction with specific preferred embodiments, provides a further detailed explanation of the present invention. It should not be construed that the specific implementation of the present invention is limited to these descriptions. For those skilled in the art, various simple deductions or substitutions can be made without departing from the concept of the present invention, and all such modifications and substitutions should be considered within the scope of protection of the present invention.

Claims

1. A recycled water irrigation system based on ultraviolet peroxo-organic acid combination, characterized by: The application relates to a POA dosing device for reclaimed water treatment, which comprises a shell, a POA dosing tank and a control unit, the lower part of the shell is provided with a water inlet, the upper part of the shell is provided with a water outlet, the water inlet is provided with a lifting pump, the water outlet is connected to a neutralization tank, and the neutralization tank is connected to an irrigation module. A glass inner container is arranged in the shell, the inside of the glass inner container is divided into a first chamber, a second chamber and a third chamber which are sequentially communicated through baffles, the water inlet is communicated with the first chamber, and the third chamber is communicated with the water outlet. A filter grid is arranged in the first chamber. An ultraviolet light intensity sensor is arranged in the second chamber. Active carbon is arranged in the connecting pipeline between the second chamber and the third chamber. A UV-Vis spectrometer with an embedded quartz cuvette is arranged at the top of the third chamber, a nozzle, a stirring mechanism, a spiral mixer and a glass electrode pH sensor are arranged in the third chamber, and an ultraviolet lamp is arranged at the bottom of the third chamber; the nozzle is located below the water inlet of the third chamber and faces the third chamber; and the ultraviolet lamp is electrically connected with the ultraviolet light intensity sensor. The POA dosing tank is connected with the nozzle through a POA agent metering pump. The control unit is electrically connected with the lifting pump, the ultraviolet lamp, the ultraviolet light intensity sensor, the UV-Vis spectrometer and the POA agent metering pump. The control unit is internally provided with a standard spectrum database, a multivariate correction model and an intelligent decision module based on a Bayesian optimization algorithm; the standard spectrum database pre-stores characteristic spectrum data of main pollutants in reclaimed water; the multivariate correction model is established based on a partial least square method or a principal component regression algorithm and is used for inverting real-time concentrations of pollutants through absorbance feedback of the UV-Vis spectrometer; the intelligent decision module takes ultraviolet light intensity and oxidant dosing quantity as input parameters X and takes treatment effect and operation cost as output targets Y, substitutes a Gaussian process GP model to fit operation parameters and outputs optimal configurations, and dynamically optimizes the intensity of the ultraviolet low-pressure mercury lamp and the dosing quantity of the POA agent metering pump.

2. The UV peroxo organic acid combination based recycled water irrigation system as claimed in claim 1, wherein: Spiral flow guide lines are arranged on the inner wall of the first chamber; a vibration sensor and a pressure transmitter are arranged in the connecting pipeline between the first chamber and the second chamber, the vibration sensor and the pressure transmitter are electrically connected with a controller, the controller is electrically connected with the lifting pump through an emergency stop circuit, and the emergency stop circuit is provided with an emergency stop button. The logic of the controller is set as follows: when the real-time vibration value fed back by the vibration sensor is greater than a preset upper threshold value, and the real-time pressure value fed back by the pressure transmitter is less than a preset lower threshold value or greater than a preset upper threshold value for more than a preset delay time, the controller triggers an audible and light alarm and cuts off the power supply of the lifting pump.

3. The UV peroxo organic acid combination based recycled water irrigation system as claimed in claim 2, wherein: Water guns are mounted at the front end and the rear end of the quartz cuvette, the water guns are regularly started to carry out air-water mixed backwashing, and the attachments on the surface of the cuvette are removed; The spiral mixer is a three-section structure, the spiral angle is 45 DEG, and the spiral mixer is used for making water flow form a cyclone to prolong the contact time of POA and ultraviolet light. The third chamber is provided with a glass electrode pH sensor, which is electrically connected with a control unit. The control unit controls the start of the POA medicament metering pump according to the information fed back by the glass electrode pH sensor, so as to control the dosage of POA and stabilize the pH of the water body at 6-8.

4. The UV peroxo organic acid combination based recycled water irrigation system as claimed in claim 2, wherein: The control unit is also connected with a weather forecast data interface, and the control unit stores local historical water quality data, meteorological data and plant water demand model. The control unit makes irrigation decision according to weather forecast data: if the probability and amount of rainfall in a certain future time are predicted to exceed the set threshold, the planned irrigation task is cancelled; if a gale warning is received, the sprinkling irrigation mode is prohibited, and the drip irrigation or irrigation is stopped; The control unit dynamically adjusts the working mode of UV disinfection and POA oxidation through the Bayesian optimization algorithm according to the organic matter concentration data of the influent detected by the UV-Vis spectrometer. When the influent organic matter concentration is lower than the lower limit threshold of the organic matter concentration, the mode of mainly using ultraviolet disinfection and supplementarily using POA dosage is adopted. When the influent organic matter concentration is higher than the upper limit threshold of the organic matter concentration, the POA dosage concentration is automatically increased.

5. The UV-peroxy organic acid combination based recycled water irrigation system as claimed in claim 4, wherein: The plant water demand model is established based on the Penman formula. The input variable X of the model includes temperature, humidity, wind speed and solar radiation intensity, and the output variable Y is the plant evapotranspiration, and the formula is Y = k1×solar radiation intensity + k2×temperature + k3×humidity + k4×wind speed, wherein k1, k2, k3 and k4 are empirical coefficients obtained by fitting local historical data.

6. The UV peroxo organic acid combination based recycled water irrigation system as claimed in claim 4, wherein: The Bayesian optimization algorithm substitutes a Gaussian process GP model to fit the operation parameters, the input parameters X = [ultraviolet light intensity, oxidant dosage] and the output target Y = [treatment effect, operation cost] are established, and the GP model is subjected to a Gaussian process f(X) ~ GP(μ(X), k(X, X′)); wherein μ(X) is a mean function; k(X, X′) is a covariance function; based on the GP model, an acquisition function is used to explore the optimal parameter configuration and the most valuable parameter point, the expectation EI(X) of the target function f(X) relative to the optimal solution f*(X) is calculated at a certain point m, that is, E(max(m, f*(X)-f(X))), and the parameter point xn that makes EI(X) reach the maximum value is found in the feasible region, the xn parameter is fed to the execution unit, and the actual operation cost yn under the parameter is collected, and the data pair (xn, yn) is expanded to the historical database; the above steps are repeated to continuously update the GP model and explore new parameter points until a preset iteration number is reached or the cost improvement of continuous iterations is lower than a threshold value, and finally the optimal operation parameter combination (Xn, Yn) is output, and the optimization cycle is completed.

7. The UV peroxo organic acid combination based recycled water irrigation system as claimed in claim 2, wherein: The neutralization tank is provided with a sodium hydroxide solution adding module for adjusting the effluent pH to 6-8; and the irrigation module is provided with a clean water flushing control module for flushing the pipeline after irrigation; The filter grid comprises a coarse grid and a fine grid, which are arranged in sequence along the water flow direction. The connecting pipeline between the POA medicament metering pump and the POA dosing tank is a PVDF-lined stainless steel pipe, the POA medicament metering pump is a diaphragm metering pump, and the diaphragm material is polytetrafluoroethylene; the outer wall of the glass liner is provided with a touch screen, and the touch screen is connected with a control unit.

8. A water treatment method based on the UV-peroxy organic acid combination based recycled water irrigation system according to any one of claims 2-7, characterized by: The method comprises the following steps: Step S1, the effluent of the secondary sedimentation tank is lifted to the first chamber by a lifting pump, and after being filtered by a filter grid, enters the second chamber; Step S2, the water removes impurities by passing through an activated carbon adsorption layer, and flows through the second chamber; at the same time, the controller monitors the equipment running state based on the data of the vibration sensor and the pressure transmitter, identifies pipeline blockage and pump abnormality through water flow pressure, and monitors light intensity distribution and lamp tube aging degree based on the data of the ultraviolet light intensity sensor; Step S3, the water flow enters the third chamber, and a UV-Vis spectrometer monitors water quality in real time; the control unit inverses pollutant concentration, and dynamically adjusts the intensity of the ultraviolet low-pressure mercury lamp and the dosage of the POA medicament based on real-time water quality and a Bayesian optimization algorithm, so as to realize efficient disinfection and oxidation; Step S4, the treated water is used for greening irrigation after entering the neutralization tank.

9. The water treatment method for the UV-peroxy organic acid combination-based recycled water irrigation system according to claim 8, characterized in that: In step S3, when the inversely obtained organic matter concentration continuously falls below a preset threshold value, the intelligent decision module preferentially explores a parameter space of high ultraviolet light intensity and low POA dosage, so that the system runs in a mode in which ultraviolet light is the main and POA is the auxiliary.

10. The water treatment method for the UV peroxo organic acid combination-based recycled water irrigation system according to claim 8, characterized in that: Step S2 further comprises data input and prediction, historical water quality data, plant water demand, weather forecast information, rainfall, and plant greening irrigation demand are input into the control unit, so as to realize advance adjustment of running parameters.

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