Reverse osmosis membrane fouling on-line detection system and method

Abstract

The present application belongs to the technical field of membrane wastewater advanced treatment, and provides a reverse osmosis membrane fouling online detection system and method. The system comprises a cleaning part, which cleans multiple membrane elements to make the performance parameters consistent before the detection period; a shielding part, which eliminates the fouling caused by single or / and multiple fouling factors on the membrane elements; a fouling parameter detection part, which detects the fouling parameters of the multiple membrane elements after cleaning and shielding, respectively obtains the initial fouling parameters and the updated fouling parameters corresponding to the single fouling factors and the total fouling factors; and an analysis part, which obtains the contribution degree of the fouling parameter change through the initial fouling parameters and the updated fouling parameters corresponding to the single fouling factors and the total fouling factors, and obtains the contribution degree of each fouling factor. The present application can predict the influence of various pollutants causing reverse osmosis membrane fouling.

Description

Technical Field

[0001] This invention relates to the field of membrane-based advanced wastewater treatment technology, specifically to an online detection system and method for reverse osmosis membrane fouling. Background Technology

[0002] Reverse osmosis technology plays an important role in the field of deep wastewater treatment and reuse. While realizing the recycling of wastewater, various pollutants in the wastewater adhere to the membrane surface. After long-term concentration and enrichment, the pollutants on the membrane surface gradually accumulate and block the flow channels of the membrane element, causing membrane element fouling.

[0003] Membrane fouling can cause a decrease in water production. In order to maintain water production, the feed water pressure needs to be increased, which further aggravates membrane fouling and increases the power consumption of the water production process.

[0004] When the membrane elements become fouled to a certain extent, the reverse osmosis unit needs to be shut down and the membrane elements chemically cleaned.

[0005] Due to the complex composition and large fluctuations in wastewater quality, analyzing membrane fouling and predicting trends has always been a challenge for the industry.

[0006] Existing technologies include methods that use flat membranes to simulate membrane fouling and membrane surface flux to predict reverse osmosis membrane fouling. However, in actual wastewater deep treatment projects, the reverse osmosis membranes used are spiral wound membrane modules. Reverse osmosis fouling is not only affected by membrane surface flux, but also by the obstruction of the separator and the scouring of the concentrate surface. More importantly, as the feed water concentration increases, the factors affecting membrane fouling (pollutants) change dynamically. Therefore, the above-mentioned technical solutions cannot truly reflect the trend and location of membrane fouling, let alone the magnitude of the pollution contribution of each pollutant causing fouling.

[0007] Existing technologies include solutions that use a dissolution-diffusion model combined with neural networks to predict fouling caused by scale-forming ions in reverse osmosis membranes. However, these solutions focus solely on scale-forming ions, resulting in a single influencing factor in fouling prediction. In wastewater treatment engineering, in addition to scale-forming ions, inorganic colloids, organic pollutants, and microorganisms also contribute to membrane fouling. Organic pollutants and microorganisms are the most significant factors causing membrane fouling. Fouling caused by scaling is often easily predicted, and effective cleaning solutions are readily available. The aforementioned technologies cannot predict the combined effects of inorganic colloids, organic pollutants, microorganisms, and sparingly soluble salts on membrane fouling in wastewater reuse systems.

[0008] Therefore, predicting the impact of various pollutants that cause reverse osmosis membrane fouling has become a pressing technical challenge. Summary of the Invention

[0009] To achieve the technical objective of predicting the impact of various contaminants that cause reverse osmosis membrane fouling, this invention provides an online detection system and method for reverse osmosis membrane fouling.

[0010] According to a first aspect of the present invention, an online detection system for reverse osmosis membrane fouling is provided, comprising a cleaning unit, a shielding unit, a fouling parameter detection unit, and an analysis unit: The cleaning unit is configured to clean multiple membrane elements so that the performance parameters of the multiple membrane elements are consistent before the testing cycle. The performance parameters include fouling parameters and membrane element weight. The shielding portion is configured to eliminate fouling of the membrane element by a single or / and multiple fouling factors, the fouling factors including one or more of carbonates, other total inorganic salts, organic matter, microorganisms and colloids; The fouling parameter detection unit is configured to detect the fouling parameters of multiple membrane elements after cleaning by the cleaning unit at the beginning of the detection cycle, as initial fouling parameters; detect the fouling parameters of multiple membrane elements after shielding by the shielding unit at the end of the detection cycle, and detect the fouling parameters of at least one membrane element after cleaning by the cleaning unit but not shielded by the shielding unit, respectively obtaining updated fouling parameters corresponding to individual fouling factors and updated fouling parameters corresponding to the total fouling factor; the fouling parameters include one or more of the following: inlet pressure, outlet pressure, differential pressure, permeate flow rate, and concentrate flow rate; The analysis unit is configured to obtain the contribution of the individual fouling factor to the change in the fouling parameter corresponding to the total fouling factor within the detection period by the initial fouling parameter and the updated fouling parameter detected by the fouling parameter detection unit, thereby obtaining the contribution of each fouling factor.

[0011] This invention constructs an online reverse osmosis membrane fouling detection system through the collaborative work of a cleaning unit, a shielding unit, a fouling parameter detection unit, and an analysis unit. This effectively solves the technical challenge of existing technologies being unable to accurately predict and differentiate the combined effects of multiple contaminants on membrane fouling. The cleaning unit first cleans multiple membrane elements until their performance parameters are consistent, ensuring a unified testing standard. The shielding unit eliminates the influence of specific fouling factors such as carbonates, inorganic salts, organic matter, microorganisms, and colloids, enabling independent analysis of each factor. The fouling parameter detection unit accurately collects the initial and updated fouling parameters of each membrane element during the detection cycle. Finally, the analysis unit calculates the contribution of each fouling factor to the total fouling based on these data. This invention not only accurately reflects the dynamic trend of membrane fouling but also quantitatively assesses the contribution of different contaminants (including unpredictable organic matter and microorganisms), thereby achieving accurate analysis and prediction of combined fouling of reverse osmosis membranes under complex wastewater conditions, providing a reliable basis for formulating scientific cleaning and maintenance strategies.

[0012] In one possible implementation, the shielding portion includes a contamination blank test module and one or more of the following: an inorganic salt contamination test module, a carbonate contamination test module, an organic contamination test module, a microbial contamination test module, and a colloidal contamination test module. The inorganic salt fouling test module includes a hydrochloric acid dosing component and a scale inhibitor dosing component: the hydrochloric acid dosing component is used to eliminate the influence of carbonate fouling factors on membrane fouling; the scale inhibitor dosing component is used to eliminate the influence of non-carbonate fouling factors on membrane fouling. The carbonate fouling test module includes a hydrochloric acid dosing component, which is used to eliminate the impact of carbonate fouling factors on membrane fouling. The organic fouling test module includes a sodium hydroxide dosing component: the sodium hydroxide dosing component is used to eliminate the influence of organic fouling factors on membrane fouling; The microbial fouling test module includes a sodium hypochlorite dosing component and an ultraviolet sterilizer component: the sodium hypochlorite dosing component and the ultraviolet sterilizer component are used to eliminate the influence of microbial fouling factors on membrane fouling; The colloidal fouling test module includes a high-precision filter assembly with a filtration accuracy of 10-100 nanometers, which is used to eliminate the influence of colloidal fouling factors on membrane fouling. The fouling blank test module serves as a blank control module for other test modules. It is used to directly clean the membrane element with raw water and, in conjunction with the fouling parameter detection unit, obtain updated fouling parameters of the membrane element under conditions where no shielding agent is used.

[0013] This invention constructs an online detection system capable of accurately separating and quantifying the contribution of various pollutants to reverse osmosis membrane fouling by setting up a fouling blank test module and dedicated test modules for key fouling factors such as inorganic salts, carbonates, organic matter, microorganisms, and colloids. Each shielding module "shields" a single fouling factor through specific agents or physical means (such as hydrochloric acid to eliminate carbonates, scale inhibitors to suppress non-carbonate scaling, sodium hydroxide to degrade organic matter, sodium hypochlorite and ultraviolet light to synergistically inactivate microorganisms, and high-precision filters to trap colloids). The fouling blank test module provides a raw water control group without intervention. Combined with the simultaneous collection of key parameters such as feed water pressure, differential pressure, and permeate flow rate of each membrane element by the fouling parameter detection unit at the initial state after cleaning and at the end of the detection cycle, the analysis unit can accurately calculate the independent contribution of each type of pollutant to membrane fouling under real and complex water quality conditions. This invention breaks through the limitations of existing technologies that only focus on fouling ions or rely on flat membrane simulation. For the first time, it realizes the dynamic decoupling and quantitative assessment of the combined fouling effect of multiple pollutants (especially organic matter, microorganisms and colloids) in the actual engineering operation of spiral wound membrane modules. This significantly improves the accuracy of fouling trend prediction and the targeting of cleaning strategies, thereby effectively extending membrane life, reducing energy consumption and ensuring the stable and efficient operation of wastewater reuse systems.

[0014] In one possible implementation, the hydrochloric acid dosing assembly, the scale inhibitor dosing assembly, the sodium hydroxide dosing assembly, and the sodium hypochlorite dosing assembly include: The membrane includes a dosing chamber, a dosing pump, and a dosing pipeline. The dosing chamber is used to contain a shielding agent, and the dosing pump is used to pump the shielding agent from the dosing chamber into the membrane element through the dosing pipeline.

[0015] In one possible implementation, the colloidal fouling test module further includes a booster pump for pressurizing the wastewater before it enters the high-precision filter.

[0016] In one possible implementation, the cleaning unit includes a cleaning water tank, a cleaning pump, and a cleaning circuit: The chemical agents in the cleaning tank are introduced into the membrane element through the cleaning pump and cleaning circuit to clean the membrane element. The resulting permeate containing the chemical agents is returned to the cleaning tank through the cleaning circuit, forming a cycle of cleaning the membrane element.

[0017] In one possible implementation, the cleaning unit further includes a security filter disposed in the cleaning circuit between the cleaning pump and the membrane element.

[0018] In one possible implementation, the fouling parameter detection unit includes one or more of the following components: A flow meter is used to detect water flow. Pressure gauges are used to detect the inlet and outlet water pressures of membrane elements; A differential pressure sensor is used to detect the pressure difference between the inlet and outlet water pressures of a membrane element.

[0019] In one possible implementation, the fouling parameter detection unit further includes: The control module is configured to control the conduction timing of the cleaning section and the shielding section, the timing including: When the cleaning section is turned on, the permeate and concentrate discharges of the corresponding membrane elements are turned off, and the permeate and concentrate of the membrane elements are returned to the cleaning section. Once the performance parameters of multiple membrane elements are consistent, the testing cycle begins. The cleaning section is closed, the shielding section is opened, and the permeate and concentrate discharges are opened until the testing cycle ends.

[0020] In one possible implementation, the control module includes multiple valves.

[0021] In one possible implementation, the analysis unit includes a differential pressure acquisition module, a flow rate acquisition module, and a contribution acquisition module: The differential pressure acquisition module is configured to detect the differential pressure of the fouling blank test module and other test modules respectively after cleaning by the fouling parameter detection unit from the cleaning unit and at the beginning of the detection cycle, and obtain the differential pressure change corresponding to the total fouling factor and the differential pressure change corresponding to the single fouling factor during the detection cycle respectively. The flow acquisition module is configured to detect the pressure water flow of the fouling blank test module and other test modules after cleaning in the cleaning department and at the start of the detection cycle by the fouling parameter detection, and to obtain the water flow change corresponding to the total fouling factor and the water flow change corresponding to the single fouling factor during the detection cycle. The contribution acquisition module is configured to obtain the pressure difference contribution of a single fouling factor based on the pressure difference change corresponding to the total fouling factor and the pressure difference change corresponding to a single fouling factor within the detection period; to obtain the water flow contribution of a single fouling factor based on the water flow change corresponding to the total fouling factor and the water flow change corresponding to a single fouling factor within the detection period; and to obtain the contribution of a single fouling factor by weighted combination of the pressure difference contribution and the water flow contribution.

[0022] This invention achieves precise quantification of the impact of various pollutants during reverse osmosis membrane fouling through the coordinated operation of the differential pressure acquisition module, flow rate acquisition module, and contribution degree acquisition module in the analysis unit. The differential pressure acquisition module and flow rate acquisition module synchronously collect data on the differential pressure and permeate flow rate changes of the fouling blank test module (reflecting total fouling) and other shielded test modules (reflecting a single fouling factor) within the detection period, based on the fouling parameter detection unit. This allows for the separation of the performance degradation characteristics of each pollutant (such as carbonates, organic matter, microorganisms, colloids, etc.) under individual action. The contribution degree acquisition module further converts the differential pressure and flow rate changes caused by a single fouling factor into differential pressure contribution degree and flow rate contribution degree, respectively, and obtains a comprehensive contribution degree through weighted fusion, truly reflecting the actual impact weight of each pollutant on membrane fouling under complex wastewater conditions. This invention breaks through the limitations of existing technologies that rely solely on a single indicator (such as flux or fouling ion concentration) for prediction. For the first time, it achieves decoupled analysis and quantitative assessment of multi-factor complex fouling under actual operating conditions of spiral wound membranes. This significantly improves the accuracy of fouling trend judgment, the targeting of cleaning solutions, and the energy efficiency and stability of system operation, providing reliable technical support for wastewater deep treatment and reuse projects.

[0023] In one possible implementation, the reverse osmosis membrane fouling online detection system further includes a permeate branch, which is located at the permeate end of the membrane element. The permeate branch includes a loop end controllably connected to the cleaning unit and a discharge end for controllable discharge of permeate.

[0024] In one possible implementation, the reverse osmosis membrane fouling online detection system further includes a concentrate branch, which is located at the concentrate end of the membrane element. The concentrate branch includes a loop end controllably connected to the cleaning unit and a discharge end for controllable discharge of concentrate.

[0025] In one possible implementation, the membrane element is a spiral wound membrane element.

[0026] In one possible implementation, the online detection system for reverse osmosis membrane fouling further includes a membrane housing, which is provided with at least one reverse osmosis membrane or a spiral wound membrane element, and the membrane housing is provided with an inlet and an outlet.

[0027] According to a second aspect of the present invention, an online detection method for reverse osmosis membrane fouling is provided, comprising: Cleaning steps: Clean multiple membrane elements to ensure that the performance parameters of the multiple membrane elements are consistent before testing. The performance parameters include fouling parameters and membrane element weight. Initial fouling parameter detection steps: At the beginning of the detection cycle, detect the fouling parameters of multiple membrane elements with consistent parameters after cleaning to obtain the initial fouling parameters; the fouling parameters include one or more of the following: inlet pressure, outlet pressure, pressure difference, permeate flow rate, and concentrate flow rate; Shielding steps: Eliminate fouling of membrane elements caused by single or / and multiple fouling factors; Update fouling parameter detection steps: At the end of the detection cycle, detect the fouling parameters of the shielded membrane element and the membrane element after the initial fouling parameter detection but without the shielding step, so as to obtain the updated fouling parameters corresponding to a single fouling factor and the updated fouling parameters corresponding to the total fouling factor. Contribution determination steps: Based on the initial and updated fouling parameters corresponding to a single fouling factor, obtain the change in fouling parameters corresponding to that single fouling factor within the detection period; based on the initial and updated fouling parameters corresponding to the total fouling factor, obtain the change in fouling parameters corresponding to the total fouling factor within the detection period; based on the contribution of each fouling factor to the change in fouling parameters corresponding to the total fouling factor, obtain the contribution of each fouling factor.

[0028] This invention establishes an online, quantitative analysis method for detecting complex fouling mechanisms in reverse osmosis membranes through the organic synergy of five steps: cleaning, initial fouling parameter detection, shielding, updated fouling parameter detection, and contribution determination. This effectively overcomes the shortcomings of existing technologies that cannot accurately reflect the coupled fouling behavior of spiral wound membranes under complex wastewater conditions. The method first ensures consistent initial performance across multiple membrane elements through a cleaning step, eliminating interference from individual differences. Then, at the beginning and end of the detection cycle, key fouling parameters such as pressure difference and flow rate are collected from membrane elements treated with specific factors and those without shielding (blank control). This accurately separates the performance degradation caused by single fouling factors such as carbonates, inorganic salts, organic matter, microorganisms, and colloids. Finally, by comparing the parameter changes caused by a single factor with the total fouling, the contribution of each pollutant is calculated. This method not only breaks through the limitations of traditional models that only focus on scale-forming ions or rely on simplified flat membrane experiments, but also, for the first time, achieves a quantitative assessment of the contributions of difficult-to-predict but more harmful organic matter, microorganisms and colloidal pollution under actual engineering operation conditions. This provides a scientific basis for accurate early warning, targeted cleaning and optimized operation, and significantly improves the stability, energy efficiency and economy of reverse osmosis process in wastewater reuse systems.

[0029] In one possible implementation, the online detection method for reverse osmosis membrane fouling further includes: Decision-making steps: Determine the cleaning strategy based on the contribution of each fouling factor. The cleaning strategy includes using the chemical agent corresponding to the fouling factor with the largest contribution for cleaning.

[0030] This invention further introduces a decision-making step, directly linking the quantitative contribution of each fouling factor to the formulation of the cleaning strategy, achieving a technological leap from "passive cleaning" to "precise targeted cleaning." The synergistic action of cleaning, parameter detection, shielding, and contribution calculation steps not only accurately identifies the dominant pollutants causing membrane performance degradation (such as organic matter, microorganisms, colloids, or inorganic scale) but also quantifies their relative impact. Based on this, the decision-making step prioritizes specific chemical agents (such as alkaline washing to remove organic matter, bactericides to control microorganisms, and acid washing to remove carbonates) targeting the main fouling factors, avoiding the problems of agent waste, membrane damage, or incomplete cleaning caused by traditional "one-size-fits-all" cleaning schemes. This invention effectively solves the problem of blind cleaning due to the inability to distinguish the roles of various factors in complex fouling, significantly improving cleaning efficiency and membrane system operational stability, while reducing energy consumption and maintenance costs. It provides a new intelligent and refined path for fouling control in wastewater deep treatment and reuse projects.

[0031] In one possible implementation, the shielding step includes one or more of the following steps: Hydrochloric acid and scale inhibitor are continuously added to the influent until the pressure difference change exceeds the set range or / and the pressure difference reaches the set pressure difference threshold. Hydrochloric acid is continuously added to the influent until the pressure difference change exceeds the set range or / and the pressure difference reaches the set pressure difference threshold. Continuously add liquid alkali to the influent until the pressure difference change exceeds the set range or / and the pressure difference reaches the set pressure difference threshold. Sodium hypochlorite is continuously added to the influent until the pressure difference change exceeds the set range or / and the pressure difference reaches the set pressure difference threshold. Multiple filtrations are performed using filters until the differential pressure change exceeds the set range or / and the differential pressure reaches the set differential pressure threshold.

[0032] This invention achieves precise suppression and process controllability of different fouling factors by flexibly employing targeted intervention methods such as hydrochloric acid, scale inhibitors, liquid alkali, sodium hypochlorite addition, or high-precision filtration in the shielding step, and using pressure difference changes or pressure difference thresholds as dynamic termination conditions. This strategy works closely in conjunction with cleaning, initial / renewal fouling parameter detection, and contribution calculation steps: on the one hand, various agents or filtration methods effectively shield specific contaminant sources such as carbonates, non-carbonate inorganic scale, organic matter, microorganisms, and colloids, ensuring the separability of the fouling response under a single variable; on the other hand, using the dynamic change of membrane system pressure difference during actual operation as the termination criterion for shielding operation avoids under- or over-shielding problems caused by fixed-time or fixed-dosage addition, making the experiment closer to real-world operating conditions. Therefore, this invention overcomes the shortcomings of existing technologies, such as reliance on experience-based judgment, inability to quantify multi-factor coupled fouling, and blind cleaning. It not only improves the accuracy and reproducibility of fouling factor identification, but also provides reliable data support for subsequent contribution-based targeted cleaning, significantly enhancing the operational stability, cleaning efficiency, and resource utilization efficiency of reverse osmosis systems under complex water conditions.

[0033] In one possible implementation, the contribution determination step includes: The contribution of each fouling factor is obtained using the following formula:

[0034] in, For the first The contribution of each contamination factor; , These are flow rate weight and pressure difference weight, respectively. + =1; For the first The contribution of each fouling factor to flow attenuation. , For the first The permeate flow rate attenuation value within the detection period corresponding to each fouling factor. This represents the permeate flow rate attenuation value within the detection period corresponding to the total fouling factor. Contribution to the increase in pressure differential of fouling factors, , For the first The incremental value of differential pressure change within the detection cycle corresponding to each fouling factor. This represents the incremental value of the differential pressure change within the detection period corresponding to the total fouling factor.

[0035] This invention obtains the single permeate flow rate attenuation value (ΔQ) corresponding to the total fouling factor through a shielding experiment. i ΔQ0) and pressure difference growth (ΔP) i Substitute ΔP0 into the contribution calculation model (in , ,and This invention achieves a multi-dimensional, weighted quantitative assessment of the contribution of each fouling factor. The model is deeply integrated with steps such as cleaning consistency control, dynamic shielding intervention (e.g., agent addition to trigger at the differential pressure threshold), and dual-parameter synchronous detection: the cleaning step ensures the comparability of initial states, the shielding step precisely isolates specific fouling mechanisms, the parameter detection step provides reliable input data, and the mathematical model integrates two complementary physical indicators: flow rate decline (reflecting flux loss) and differential pressure increase (reflecting resistance accumulation). This overcomes technical bottlenecks such as the susceptibility of single parameters to operational fluctuations and the difficulty in distinguishing between organic and inorganic fouling. Therefore, this invention not only solves the problems of ambiguous fouling attribution and empirical cleaning strategies in existing technologies, but also achieves objective identification and priority ranking of dominant factors in complex fouling under real-world operating conditions. This provides a scientific basis for intelligent decision-making regarding cleaning agent type and intensity, significantly improving the accuracy of reverse osmosis system fouling diagnosis, the targeting of cleaning, and the long-term economic efficiency and reliability of operation.

[0036] This invention provides a method for real-time feedback on the contribution of reverse osmosis membrane fouling factors to membrane fouling. The membrane fouling detection and evaluation method can promptly diagnose the main fouling factors affecting membrane fouling, take targeted pretreatment improvement measures to alleviate reverse osmosis membrane fouling, extend the operating cycle of the reverse osmosis membrane, and provide a precise cleaning solution for reverse osmosis by combining the contribution of fouling factors.

[0037] This invention dynamically simulates the fouling of reverse osmosis membrane systems in advanced wastewater treatment systems using actual influent water quality, actual operating flux, and actual spiral wound membrane elements. During normal operation of the reverse osmosis system, the contribution of different pollutants to membrane fouling can be detected in real time, allowing for targeted corrective measures in pretreatment. After membrane fouling occurs, a membrane cleaning plan can be quickly determined based on process monitoring data. Attached Figure Description

[0038] Figure 1 This is a schematic block diagram of one embodiment of the online detection system for reverse osmosis membrane fouling described in this invention; Figure 2 This is a schematic diagram of an embodiment of the online detection system for reverse osmosis membrane fouling described in this invention; Figure 3 This is a schematic flowchart of an embodiment of the online detection method for reverse osmosis membrane fouling described in this invention; Figure 4 This is a schematic diagram of a preferred embodiment of the online detection method for reverse osmosis membrane fouling described in this invention; Figure 5This is a schematic diagram of an embodiment of the five-dimensional model of the contribution of each fouling factor described in this invention; The system includes: 100. Reverse osmosis membrane fouling online detection system; 1. Cleaning section; 11. Cleaning water tank; 12. Cleaning pump; 13. Security filter; 14. Cleaning circuit; 2. Shielding section; 21. Inorganic salt fouling test module; 211. Hydrochloric acid dosing assembly; 212. Scale inhibitor dosing assembly; 22. Carbonate fouling test module; 23. Organic fouling test module; 231. Sodium hydroxide dosing assembly; 24. Microbial fouling test module; 241. Ultraviolet sterilizer assembly; 242. Sodium hypochlorite dosing assembly; 25. Glue Module for fouling test; 251, Booster pump; 252, High-precision filter assembly; 26, Fouling blank test module; 201, Dosing chamber; 202, Dosing pump; 203, Dosing pipeline; 3, Fouling parameter detection unit; 31, Sensor assembly; 311, Flow meter; 312, Pressure gauge; 32, Control module; 321, Valve; 4, Analysis unit; 41, Differential pressure acquisition module; 42, Flow rate acquisition module; 43, Contribution acquisition module; 5, Inlet branch; 6, Permeate branch; 7, Concentrate branch; 10, Membrane element. Detailed Implementation

[0039] Numerous specific details are set forth in the following description to provide a full understanding of the invention. However, the invention can be practiced in many other ways different from those described herein, and those skilled in the art can make similar extensions without departing from the spirit of the invention. Therefore, the invention is not limited to the specific embodiments disclosed below.

[0040] Existing technologies have significant shortcomings in predicting reverse osmosis membrane fouling: flat membrane simulation methods cannot accurately reflect the fouling trends and locations of spiral wound membrane modules in actual engineering due to screen obstruction, concentrate flushing, and dynamic water quality changes; while methods based on dissolution-diffusion models combined with neural networks only focus on predicting fouling ions, ignoring the combined effects of key fouling factors such as inorganic colloids, organic pollutants, and microorganisms. In particular, the lack of predictive ability for organic pollutants and microorganisms (the main fouling sources in actual engineering) makes it impossible to comprehensively assess the pollution contribution of each pollutant under complex wastewater quality fluctuations, and it is difficult to effectively guide membrane cleaning and maintenance.

[0041] To address the aforementioned problems, this invention provides an online reverse osmosis membrane fouling detection system 100, such as... Figure 1 As shown, the online reverse osmosis membrane fouling detection system 100 includes a cleaning unit 1, a shielding unit 2, a fouling parameter detection unit 3, and an analysis unit 4. The cleaning unit 1 is configured to clean multiple membrane elements 10, so that the performance parameters of the multiple membrane elements 10 are consistent before the detection cycle. The performance parameters include fouling parameters and the weight of membrane element 10. The shielding portion 2 is configured to eliminate fouling of the membrane element 10 by a single or / and multiple fouling factors, the fouling factors including one or more of carbonates, other total inorganic salts, organic matter, microorganisms and colloids; The fouling parameter detection unit 3 is configured to detect the fouling parameters of multiple membrane elements 10 after cleaning by the cleaning unit 1 at the beginning of the detection cycle, as initial fouling parameters; detect the fouling parameters of multiple membrane elements 10 after shielding by the shielding unit 2 at the end of the detection cycle, and detect the fouling parameters of at least one membrane element 10 after cleaning by the cleaning unit 1 but not shielded by the shielding unit 2, respectively obtaining updated fouling parameters corresponding to individual fouling factors and updated fouling parameters corresponding to the total fouling factors; the fouling parameters include one or more of the following: inlet pressure, outlet pressure, pressure difference, permeate flow rate, and concentrate flow rate; The analysis unit 4 is configured to obtain the contribution of the individual fouling factor to the change of the fouling parameter corresponding to the total fouling factor within the detection period by the initial fouling parameter and the updated fouling parameter detected by the fouling parameter detection unit 3, thereby obtaining the contribution of each fouling factor.

[0042] In one feasible embodiment, such as Figure 2 As shown, the online reverse osmosis membrane fouling detection system 100 further includes: The water production branch 6 is provided at the water production end of the membrane element 10. The water production branch 6 includes a loop end that is controllably connected to the cleaning unit 1 and a discharge end for controllably discharging the produced water.

[0043] In one feasible embodiment, such as Figure 2 As shown, the online reverse osmosis membrane fouling detection system 100 further includes: A concentrate branch 7 is provided at the concentrate end of the membrane element 10. The concentrate branch 7 includes a loop end that is controllably connected to the cleaning unit 1 and a discharge end for controllably discharging concentrate.

[0044] The following is a detailed description of each component module of the reverse osmosis membrane fouling online detection system 100: Cleaning Section 1: In one feasible embodiment, such as Figure 2 As shown, the cleaning unit 1 includes a cleaning water tank 11, a cleaning pump 12, and a cleaning circuit 14: The chemical agents in the cleaning water tank 11 enter the membrane element 10 through the cleaning pump 12 and the cleaning circuit 14 to clean the membrane element 10. The generated permeate containing the chemical agents is returned to the cleaning water tank 11 through the cleaning circuit 14, forming a cycle cleaning of the membrane element 10.

[0045] In one feasible embodiment, the cleaning unit 1 further includes a security filter 13 disposed on the cleaning circuit 14 between the cleaning pump 12 and the membrane element 10.

[0046] Shielding part 2: In one feasible embodiment, such as Figure 1 and Figure 2 As shown, the shielding part 2 includes a blank contamination test module 26 and one or more of the following: inorganic salt contamination test module 21, carbonate contamination test module 22, organic contamination test module 23, microbial contamination test module 24, and colloidal contamination test module 25: The inorganic salt fouling test module 21 includes a hydrochloric acid dosing component 211 and a scale inhibitor dosing component 212: the hydrochloric acid dosing component 211 is used to eliminate the influence of carbonate fouling factors on membrane fouling; the scale inhibitor dosing component 212 is used to eliminate the influence of non-carbonate fouling factors on membrane fouling. The carbonate fouling test module 22 includes a hydrochloric acid dosing component 211, which is used to eliminate the influence of carbonate fouling factors on membrane fouling. The organic fouling test module 23 includes a sodium hydroxide dosing component 231: the sodium hydroxide dosing component 231 is used to eliminate the influence of organic fouling factors on membrane fouling; The microbial fouling test module 24 includes a sodium hypochlorite dosing component 242 and an ultraviolet sterilizer component 241: the sodium hypochlorite dosing component 242 and the ultraviolet sterilizer component 241 are used to eliminate the influence of microbial fouling factors on membrane fouling; The colloidal fouling test module 25 includes a high-precision filter assembly 252 with a filtration accuracy of 10-100 nanometers, used to eliminate the influence of colloidal fouling factors on membrane fouling; The fouling blank test module 26 serves as a blank control module for other test modules. It is used to clean the membrane element 10 with raw water and obtain the updated fouling parameters of the membrane element 10 under the condition of not using shielding agents, in combination with the fouling parameter detection unit. That is, the raw water is directly introduced into the membrane element without any treatment, and the updated fouling parameters of the membrane element under the condition of not using shielding measures are obtained by combining the fouling parameter detection unit.

[0047] In one feasible embodiment, the hydrochloric acid dosing assembly 211, the scale inhibitor dosing assembly 212, the sodium hydroxide dosing assembly 231, and the sodium hypochlorite dosing assembly 242 include: The membrane element 10 includes a dosing chamber 201, a dosing pump 202, and a dosing pipe 203. The dosing chamber 201 is used to contain a shielding agent. The dosing pump 202 is used to pump the shielding agent from the dosing chamber 201 into the membrane element 10 through the dosing pipe 203.

[0048] In one feasible embodiment, the colloidal fouling test module 25 further includes a booster pump 251 for pressurizing the wastewater before it enters the high-precision filter.

[0049] Contamination Parameter Detection Section 3: In one feasible embodiment, such as Figure 1 As shown, the clogging parameter detection unit 3 includes a sensor assembly 31, which is used to measure clogging parameters.

[0050] In one feasible embodiment, such as Figure 2 As shown, the sensor assembly 31 includes one or more of the following components: Flow meter 311 is used to detect product water flow and / or concentrate flow; Pressure gauge 312 is used to detect the inlet and outlet water pressures of membrane element 10; A differential pressure sensor (not shown) is used to detect the pressure difference between the inlet and outlet water pressures of the membrane element 10.

[0051] In one feasible embodiment, such as Figure 1 As shown, the fouling parameter detection unit further includes: Control module 32 is configured to control the conduction timing of cleaning section 1 and shielding section 2, the timing including: When cleaning section 1 is turned on, the permeate discharge and concentrate discharge of membrane element 10 are turned off, and the permeate and concentrate of membrane element 10 are returned to cleaning section 1. Once the performance parameters of multiple membrane elements 10 are consistent, the testing cycle begins. The cleaning section 1 is closed, the shielding section 2 is opened, and the permeate discharge and concentrate discharge are opened until the testing cycle ends.

[0052] In one feasible embodiment, such as Figure 2 As shown, the control module 32 includes multiple valves 321.

[0053] Analysis Department 4: In one feasible embodiment, such as Figure 1 As shown, the analysis unit 4 includes a differential pressure acquisition module 41, a flow rate acquisition module 42, and a contribution acquisition module 43: The differential pressure acquisition module 41 is configured to detect the differential pressure of the fouling blank test module 26 and other test modules respectively after cleaning by the fouling parameter detection unit from the cleaning unit 1 and at the start of the detection cycle, and obtain the differential pressure change corresponding to the total fouling factor and the differential pressure change corresponding to the single fouling factor during the detection cycle respectively. The flow acquisition module 42 is configured to detect the pressure water flow of the fouling blank test module 26 and other test modules respectively after cleaning from the cleaning unit 1 by the fouling parameter detection and from the start of the detection cycle, so as to obtain the water flow change corresponding to the total fouling factor and the water flow change corresponding to the single fouling factor during the detection cycle respectively. The contribution acquisition module 43 is configured to obtain the pressure difference contribution of a single fouling factor based on the pressure difference change corresponding to the total fouling factor and the pressure difference change corresponding to a single fouling factor within the detection period; to obtain the water flow contribution of a single fouling factor based on the water flow change corresponding to the total fouling factor and the water flow change corresponding to a single fouling factor within the detection period; and to obtain the contribution of a single fouling factor by weighted combination of the pressure difference contribution and the water flow contribution.

[0054] Figure 2 A preferred embodiment of the online detection system for reverse osmosis membrane fouling described in this invention is shown, such as... Figure 2 As shown, the online reverse osmosis membrane fouling detection system 100 includes a cleaning unit 1, a shielding unit 2, a fouling parameter detection unit 3, an analysis unit 4, a permeate branch line 6, a concentrate branch line 7, and an inlet branch line 5. The cleaning unit includes a cleaning water tank 11, a cleaning pump 12, a security filter 13, and a cleaning circuit 14; The shielding part 2 includes an inorganic salt contamination test module 21, a carbonate contamination test module 22, an organic matter contamination test module 23, a microbial contamination test module 24, a colloidal contamination test module 25, and a contamination blank test module 26. The inorganic salt fouling test module 21 includes a hydrochloric acid dosing component 211 and a scale inhibitor dosing component 212; The carbonate fouling test module 22 includes a hydrochloric acid dosing component 211; The organic fouling test module 23 includes a sodium hydroxide dosing component 231; The microbial fouling test module 24 includes a sodium hypochlorite dosing component 242 and an ultraviolet sterilizer component 241; The colloidal fouling test module 25 includes a booster pump 251 and a high-precision filter assembly 252; The hydrochloric acid dosing assembly 211, scale inhibitor dosing assembly 212, sodium hydroxide dosing assembly 231 and sodium hypochlorite dosing assembly 242 include a dosing chamber 201, a dosing pump 202 and a dosing pipeline 203. The fouling parameter detection unit 3 includes a flow meter 311, a pressure gauge 312, and multiple valves 321; The analysis unit 4 includes a differential pressure acquisition module 41, a flow rate acquisition module 42, and a contribution acquisition module 43; Pressure gauges 312 are installed on the water inlet branch 5 and the concentrate branch 7 at both ends of the membrane element 10. Flow meters 311 are installed on the permeate branch 6 and concentrate branch 7 of the membrane element 10: in: The water inlet of the cleaning circuit 14 is connected to the water inlet of the membrane element 10 corresponding to the cleaning water tank 11 and the water inlet of the membrane element 10, which is connected to the water inlet of the membrane element 10. The water inlet of the membrane element 10 is connected to the water inlet of the membrane element 10. A valve 321 is provided between the water inlet of the membrane element 10 and the water inlet of the membrane element 10. A flow meter 311 is connected in series with the valve 321. The concentrate inlet of the cleaning circuit 14 is connected to the cleaning water tank 11 and the concentrate branch 7 of the membrane element 10 corresponding to the organic salt fouling test module, carbonate fouling test module 22, organic matter fouling test module 23, microbial fouling test module 24, colloidal fouling test module 25 and fouling blank test module 26, respectively. A valve 321 is provided between the circuit end of the concentrate branch 7 and the concentrate end of the membrane element 10, and a flow meter 311 is connected in series with the valve 321. The outlet of the cleaning circuit 14, after passing through the cleaning water tank 11, the cleaning pump 12 and the security filter 13 in sequence, is connected to the inlet of the membrane element 10 through valve 321. A flow meter 311 is connected in series with the valve 321. A valve 321 is provided between the discharge end of the water production branch 6 and the water production end of the membrane element 10, and a flow meter 311 is connected in series with the valve 321. A valve 321 is provided between the discharge end of the concentrate branch 7 and the concentrate end of the membrane element 10, and a flow meter 311 is connected in series with the valve 321. The dosing pipes 203 of the hydrochloric acid dosing assembly 211, scale inhibitor dosing assembly 212, sodium hydroxide dosing assembly 231, and sodium hypochlorite dosing assembly 242 are respectively connected to the inlet branch 5. The inlet branch 5 is connected to the inlet end of the membrane element 10. A valve 321 is provided on the inlet pipe between the end of the dosing pipe 203 connected to the inlet branch 5 and the inlet end of the membrane element 10. A flow meter 311 is connected in series with the valve 321. Preferably, the valve 321 of the inlet branch 5 connected to the sodium hypochlorite dosing assembly 242 is located between the ultraviolet sterilizer and the membrane element 10. The booster pump 251 and the high-precision filter of the colloidal fouling test module 25 are arranged sequentially on the inlet branch 5 according to the water inlet direction. A valve 321 is provided between the high-precision filter and the membrane element 10. A flow meter 311 is connected in series with the valve 321. The inlet end of the membrane element 10 of the fouling blank test module 26 is connected to the inlet branch 5, and a valve 321 is provided on the inlet branch 5, and a flow meter 311 is connected in series on the valve 321.

[0055] The above illustrates several embodiments of the reverse osmosis fouling online detection system of the present invention, but the present invention is not limited thereto. The reverse osmosis fouling online detection system may also include a membrane housing, wherein the membrane housing is provided with at least one reverse osmosis membrane or a spiral wound membrane assembly, and the membrane housing is provided with an inlet and an outlet.

[0056] Figure 3 This is a schematic flowchart of an embodiment of the online detection method for reverse osmosis membrane fouling described in this invention, as follows: Figure 3 As shown, the online detection method for reverse osmosis membrane fouling includes: Step S1: Clean multiple membrane elements to ensure that the performance parameters of the multiple membrane elements are consistent before testing. The performance parameters include fouling parameters and membrane element weight. Step S2: At the start of the detection cycle, detect the fouling parameters of multiple membrane elements with consistent parameters after cleaning to obtain the initial fouling parameters; the fouling parameters include one or more of the following: inlet pressure, outlet pressure, differential pressure, permeate flow rate, and concentrate flow rate; Step S3: Eliminate fouling of membrane elements caused by single or / and multiple fouling factors, respectively; Step S4: At the end of the detection cycle, detect the fouling parameters of the shielded membrane element and the membrane element after the initial fouling parameter detection but without the shielding step, so as to obtain the updated fouling parameters corresponding to a single fouling factor and the updated fouling parameters corresponding to the total fouling factor. Step S5: Based on the initial and updated fouling parameters corresponding to a single fouling factor, obtain the change in fouling parameters corresponding to that single fouling factor within the detection period; based on the initial and updated fouling parameters corresponding to the total fouling factor, obtain the change in fouling parameters corresponding to the total fouling factor within the detection period; based on the contribution of each fouling factor to the change in fouling parameters corresponding to the total fouling factor, obtain the contribution of each fouling factor.

[0057] In one feasible embodiment, the online detection method for reverse osmosis membrane fouling further includes: The cleaning strategy is determined based on the contribution of each fouling factor, and the cleaning strategy includes using the chemical agent corresponding to the fouling factor with the largest contribution for cleaning.

[0058] The following details each step of the online detection method for reverse osmosis membrane fouling:

[0059] Step S1: Cleaning Step

[0060] In one feasible embodiment, such as Figure 4 and Figure 2 As shown, step S1 includes: Open valve 321 between the outlet of cleaning circuit 14 and the inlet of membrane element 10, valve 321 between the inlet of cleaning circuit 14 and the return of product water branch 6, and valve 321 between the inlet of cleaning circuit 14 and the return of concentrate branch 7 to perform circulating cleaning of membrane element 10.

[0061] Step S2: Initial fouling parameter detection steps: In one feasible embodiment, such as Figure 4 and Figure 2 As shown, step S2 includes: The valve 321 between the outlet of the cleaning circuit 14 and the inlet of the membrane element 10, the valve 321 between the inlet of the cleaning circuit 14 and the return of the product water branch 6, and the valve 321 between the inlet of the cleaning circuit 14 and the return of the concentrate branch 7 are closed. Open valve 321 between inlet branch 5 and inlet end of membrane element 10, valve 321 between product water end of membrane element 10 and outlet end of product water branch 6, and valve 321 between concentrate end of membrane element 10 and outlet end of concentrate branch 7.

[0062] Step S3: Shielding Steps: In one feasible embodiment, such as Figure 4 and Figure 2 As shown, step S3 includes: Start the dosing pumps 202 of the hydrochloric acid dosing assembly 211, scale inhibitor dosing assembly 212, sodium hydroxide dosing assembly 231 and sodium hypochlorite dosing assembly 242, as well as the booster pump 251 of the colloidal fouling test module 25.

[0063] In one feasible embodiment, such as Figure 4 As shown, step S3 includes: Hydrochloric acid is continuously added to the influent until the pressure difference change exceeds the set range or / and the pressure difference reaches the set pressure difference threshold. Continuously add liquid alkali to the influent until the pressure difference change exceeds the set range or / and the pressure difference reaches the set pressure difference threshold. Sodium hypochlorite is continuously added to the influent until the pressure difference change exceeds the set range or / and the pressure difference reaches the set pressure difference threshold. Multiple filtrations are performed using filters until the differential pressure change exceeds the set range or / and the differential pressure reaches the set differential pressure threshold. Hydrochloric acid and scale inhibitor are continuously added to the influent until the pressure difference change exceeds the set range or / and the pressure difference reaches the set pressure difference threshold.

[0064] In a preferred embodiment, step S3 includes: Hydrochloric acid is continuously added to the influent, and the pH is controlled between 2 and 4, until the pressure difference change is greater than the set range or / and the pressure difference reaches the set pressure difference threshold. Continuously add liquid alkali to the influent, and control the pH between 10 and 12 until the pressure difference change is greater than the set range or / and the pressure difference reaches the set pressure difference threshold. Sodium hypochlorite is continuously added to the influent, and the free chlorine is controlled between 1-2 mg / L until the pressure difference change is greater than the set range or / and the pressure difference reaches the set pressure difference threshold. Multiple filtrations are performed using filters, with filtration accuracy controlled between 10 and 100 nanometers until the pressure difference change exceeds the set range or / and the pressure difference reaches the set pressure difference threshold. Hydrochloric acid and scale inhibitor are continuously added to the influent, and the pH is controlled between 2 and 3 until the pressure difference change is greater than the set range or / and the pressure difference reaches the set pressure difference threshold.

[0065] Existing technologies rely on a single factor for predicting pollutants and depend too much on models, failing to reflect the main factors affecting membrane fouling in a real-time and intuitive manner.

[0066] This invention achieves precise, controllable, and condition-close "shielding" of different fouling factors by setting multiple sets of intervention conditions with clear chemical or physical mechanisms in the shielding step (S3). These include an acidic environment (pH 2–4) to inhibit inorganic scaling, alkaline conditions (pH 10–12) to dissolve organic pollutants, low-concentration sodium hypochlorite (1–2 mg / L free chlorine) to inactivate microorganisms, ultra-fine filtration (0.01–0.001 μm) to remove colloidal particles, and acid + scale inhibitor synergistic blocking of the precipitation of various scale-forming ions. The pressure difference change or threshold is used as a dynamic termination criterion. This strategy works closely with the cleaning step (ensuring consistent initial performance of membrane elements), initial and updated fouling parameter detection (obtaining comparable data before and after shielding), and contribution calculation and decision-making steps. It not only effectively separates the independent influence of various factors in complex pollution but also avoids misjudgments caused by traditional static experiments or single-agent tests. Therefore, this invention overcomes the core challenges of existing technologies, such as the inability to quantitatively analyze multi-source coupled fouling mechanisms under real operating conditions and the reliance on experience for cleaning solutions. It significantly improves the accuracy of fouling diagnosis, the targeting of cleaning strategies, and the stability of system operation, while reducing chemical consumption, energy consumption, and membrane damage risks, providing reliable technical support for the intelligent operation and maintenance of reverse osmosis systems.

[0067] This invention utilizes membrane elements 10 (which can be spiral wound membrane elements 10 or discarded spiral wound membrane elements 10), using actual water sources as raw water and membrane elements 10 as a medium for evaluating membrane fouling. By applying different feed water treatment measures to multiple membrane elements 10 connected in parallel and simultaneously receiving water, the influence of single factors on membrane fouling is eliminated. Simultaneously, membrane elements 10 with untreated feed water are used as a blank to characterize the combined influence of various fouling factors (pollutants) on membrane fouling. The main causes of membrane fouling are determined and ranked by the contribution of a single fouling factor to the total fouling factor. Online analysis is then used to determine membrane fouling improvement schemes and chemical cleaning schemes.

[0068] Step S5: Steps to obtain contribution points: In one feasible embodiment, step S5 includes: The contribution of each fouling factor is obtained by the following formula (1): (1) in, For the first The contribution of each contamination factor; , These are flow rate weight and pressure difference weight, respectively. + =1; For the first The contribution of each fouling factor to flow attenuation. , For the first The permeate flow rate attenuation value within the detection period corresponding to each fouling factor. This represents the permeate flow rate attenuation value within the detection period corresponding to the total fouling factor. Contribution to the increase in pressure differential of fouling factors, , For the first The incremental value of differential pressure change within the detection cycle corresponding to each fouling factor. This represents the incremental value of the differential pressure change within the detection period corresponding to the total fouling factor.

[0069] In one specific embodiment of the present invention, such as Figure 2 and Figure 4As shown, in the wastewater deep treatment and reuse system, a distribution branch pipe is connected to the inlet branch 5 at the discharge end of the concentrate branch 7. The inlet branch 5 then branches into 6 identical membrane housings, corresponding to the inorganic salt fouling test module 21, carbonate fouling test module 22, organic fouling test module 23, microbial fouling test module 24, colloidal fouling test module 25, and fouling blank test module 26, respectively. An electric regulating valve and pressure gauge 312 are installed before the membrane housing. The membrane housing contains 1-3 cleaned used membranes, and the weight difference of each membrane element 10 is controlled within 0.1 kg. Hydrochloric acid and silicate scale inhibitor are added to the dosing pipeline in the inorganic salt fouling test module 21. Hydrochloric acid, sodium hydroxide, and sodium hypochlorite are added to the dosing pipelines in the carbonate fouling test module 22, organic fouling test module 23, and microbial fouling test module 24, respectively. An electric regulating valve, pressure gauge 312, booster pump 251, and high-precision filter are installed before the membrane housing of the colloidal fouling test module 25. For fouling testing of each fouling factor, a flow meter 311 is installed in the permeate branch 6, and a flow meter 311 and pressure gauge 312 are installed in the concentrate branch 7. The data from the flow meter 311 and pressure gauge 312 are uploaded to the computer (analysis module) for analysis. Corresponding shielding measures are taken for each fouling factor in the inlet branch 5. The sharing degree of each fouling factor is obtained by formula (1).

[0070] like Figure 5 As shown, the contribution of each fouling factor is dynamically displayed on the computer using a five-dimensional model, which allows for real-time understanding of the impact of different fouling factors on fouling.

[0071] This invention eliminates the influence of a single factor on membrane fouling by applying different feed water treatment measures to multiple membrane elements connected in parallel and receiving water simultaneously. At the same time, it uses membrane elements with untreated feed water as a blank to characterize the combined effect of various fouling factors on membrane fouling.

[0072] The main causes of membrane fouling are determined and ranked by the contribution of a single fouling factor to the composite fouling factor. A five-dimensional dynamic model is used to provide real-time feedback on the main factors affecting membrane fouling and to provide pretreatment adjustment strategies.

[0073] Based on the dynamic simulation of the accumulation of various fouling factors, targeted chemical cleaning solutions are provided.

[0074] Finally, it should be noted that the above descriptions are merely preferred embodiments of this application, and this application is not limited to the above embodiments. It is understood that other improvements and variations directly derived or conceived by those skilled in the art without departing from the spirit and concept of this application should be considered to be included within the protection scope of this application.

Claims

1. An online detection system for reverse osmosis membrane fouling, characterized in that, Includes a cleaning department, a shielding department, a fouling parameter detection department, and an analysis department: The cleaning unit is configured to clean multiple membrane elements so that the performance parameters of the multiple membrane elements are consistent before the testing cycle. The performance parameters include fouling parameters and membrane element weight. The shielding portion is configured to eliminate fouling of the membrane element by a single or / and multiple fouling factors, the fouling factors including one or more of carbonates, other total inorganic salts, organic matter, microorganisms and colloids; The fouling parameter detection unit is configured to detect the fouling parameters of multiple membrane elements after cleaning by the cleaning unit and at the beginning of the detection cycle, as the initial fouling parameters. The fouling parameters of multiple membrane elements after being shielded by the detection shield and at the end of the detection cycle, as well as the fouling parameters of at least one membrane element after being cleaned by the cleaning unit but not shielded by the detection shield, are obtained respectively to obtain the updated fouling parameters corresponding to a single fouling factor and the updated fouling parameters corresponding to the total fouling factor; the fouling parameters include one or more of the following: inlet pressure, outlet pressure, pressure difference, permeate flow rate, and concentrate flow rate. The analysis unit is configured to obtain the contribution of the individual fouling factor to the change in the fouling parameter corresponding to the total fouling factor within the detection period by the initial fouling parameter and the updated fouling parameter detected by the fouling parameter detection unit, thereby obtaining the contribution of each fouling factor.

2. The online detection system for reverse osmosis membrane fouling according to claim 1, characterized in that, The shielding section includes a contamination blank test module and one or more of the following modules: inorganic salt contamination test module, carbonate contamination test module, organic contamination test module, microbial contamination test module, and colloidal contamination test module: The inorganic salt fouling test module includes a hydrochloric acid dosing component and a scale inhibitor dosing component: the hydrochloric acid dosing component is used to eliminate the influence of carbonate fouling factors on membrane fouling; the scale inhibitor dosing component is used to eliminate the influence of non-carbonate fouling factors on membrane fouling. The carbonate fouling test module includes a hydrochloric acid dosing component, which is used to eliminate the impact of carbonate fouling factors on membrane fouling. The organic fouling test module includes a sodium hydroxide dosing component: the sodium hydroxide dosing component is used to eliminate the influence of organic fouling factors on membrane fouling; The microbial fouling test module includes a sodium hypochlorite dosing component and an ultraviolet sterilizer component: the sodium hypochlorite dosing component and the ultraviolet sterilizer component are used to eliminate the influence of microbial fouling factors on membrane fouling; The colloidal fouling test module includes a high-precision filter assembly with a filtration accuracy of 10-100 nanometers, which is used to eliminate the influence of colloidal fouling factors on membrane fouling. The fouling blank test module serves as a blank control module for other test modules. It is used to directly clean the membrane element with raw water and, in conjunction with the fouling parameter detection unit, obtain updated fouling parameters of the membrane element under conditions where no shielding agent is used.

3. The online detection system for reverse osmosis membrane fouling according to claim 2, characterized in that, The hydrochloric acid dosing assembly, scale inhibitor dosing assembly, sodium hydroxide dosing assembly, and sodium hypochlorite dosing assembly include: The membrane includes a dosing chamber, a dosing pump, and a dosing pipeline. The dosing chamber is used to contain a shielding agent, and the dosing pump is used to pump the shielding agent from the dosing chamber into the membrane element through the dosing pipeline. Or / and, the colloidal fouling test module also includes a booster pump for pressurizing the wastewater before it enters the high-precision filter.

4. The online detection system for reverse osmosis membrane fouling according to claim 1, characterized in that, The fouling parameter detection unit includes one or more of the following components: A flow meter is used to detect water flow. Pressure gauges are used to detect the inlet and outlet water pressures of membrane elements; Differential pressure sensor, used to detect the pressure difference between the inlet and outlet water pressures of membrane element; Or / and, the reverse osmosis membrane fouling online detection system further includes a permeate branch, which is located at the permeate end of the membrane element. The permeate branch includes a loop end that is controllably connected to the cleaning unit and a discharge end for controllably discharging permeate. Or / and, the reverse osmosis membrane fouling online detection system further includes a concentrate branch, which is located at the concentrate end of the membrane element. The concentrate branch includes a loop end controllably connected to the cleaning unit and a discharge end for controllably discharging concentrate. Or / and, the cleaning unit includes a cleaning water tank, a cleaning pump, and a cleaning circuit: The chemical agents in the cleaning tank are introduced into the membrane element through the cleaning pump and cleaning circuit to clean the membrane element. The resulting permeate containing the chemical agents is returned to the cleaning tank through the cleaning circuit, forming a cycle of cleaning the membrane element. Or / and, the membrane element is a spiral wound membrane element.

5. The online detection system for reverse osmosis membrane fouling according to claim 4, characterized in that, The fouling parameter detection unit also includes: The control module is configured to control the conduction timing of the cleaning section and the shielding section, the timing including: When the cleaning section is turned on, the permeate and concentrate discharges of the corresponding membrane elements are turned off, and the permeate and concentrate of the membrane elements are returned to the cleaning section. Once the performance parameters of multiple membrane elements are consistent, the testing cycle begins. The cleaning section is closed, the shielding section is opened, and the permeate and concentrate discharges are opened until the testing cycle ends. Or / and, the cleaning unit further includes a security filter disposed in the cleaning circuit between the cleaning pump and the membrane element; Or / and, the control module includes multiple valves; Or / and, the online detection system for reverse osmosis membrane fouling further includes a membrane housing, which is provided with at least one reverse osmosis membrane or a spiral wound membrane element, and the membrane housing is provided with an inlet and an outlet.

6. The online detection system for reverse osmosis membrane fouling according to claim 2, characterized in that, The analysis unit includes a differential pressure acquisition module, a flow rate acquisition module, and a contribution acquisition module. The differential pressure acquisition module is configured to detect the differential pressure of the fouling blank test module and other test modules respectively after cleaning by the fouling parameter detection unit from the cleaning unit and at the beginning of the detection cycle, and obtain the differential pressure change corresponding to the total fouling factor and the differential pressure change corresponding to the single fouling factor during the detection cycle respectively. The flow acquisition module is configured to detect the pressure water flow of the fouling blank test module and other test modules after cleaning in the cleaning department and at the start of the detection cycle by the fouling parameter detection, and to obtain the water flow change corresponding to the total fouling factor and the water flow change corresponding to the single fouling factor during the detection cycle. The contribution acquisition module is configured to obtain the pressure difference contribution of a single fouling factor based on the pressure difference change corresponding to the total fouling factor and the pressure difference change corresponding to a single fouling factor within the detection period; to obtain the water flow contribution of a single fouling factor based on the water flow change corresponding to the total fouling factor and the water flow change corresponding to a single fouling factor within the detection period; and to obtain the contribution of a single fouling factor by weighted combination of the pressure difference contribution and the water flow contribution.

7. A method for online detection of reverse osmosis membrane fouling, characterized in that, include: Cleaning steps: Clean multiple membrane elements to ensure that the performance parameters of the multiple membrane elements are consistent before testing. The performance parameters include fouling parameters and membrane element weight. Initial fouling parameter detection steps: At the beginning of the detection cycle, detect the fouling parameters of multiple membrane elements with consistent parameters after cleaning to obtain the initial fouling parameters; the fouling parameters include one or more of the following: inlet pressure, outlet pressure, pressure difference, permeate flow rate, and concentrate flow rate; Shielding steps: Eliminate fouling of membrane elements caused by single or / and multiple fouling factors; Update fouling parameter detection steps: At the end of the detection cycle, detect the fouling parameters of the shielded membrane element and the membrane element after the initial fouling parameter detection but without the shielding step, so as to obtain the updated fouling parameters corresponding to a single fouling factor and the updated fouling parameters corresponding to the total fouling factor. Contribution acquisition steps: Based on the initial and updated fouling parameters corresponding to a single fouling factor, obtain the change in fouling parameters corresponding to a single fouling factor within the detection period; The changes in the fouling parameters corresponding to the total fouling factor within the detection period are obtained based on the initial fouling parameters and updated fouling parameters corresponding to the total fouling factor. The contribution of each fouling factor is obtained by considering its contribution to the change in fouling parameters relative to the total fouling factor.

8. The online detection method for reverse osmosis membrane fouling according to claim 7, characterized in that, Also includes: Decision-making steps: Determine the cleaning strategy based on the contribution of each fouling factor. The cleaning strategy includes using the chemical agent corresponding to the fouling factor with the largest contribution for cleaning.

9. The online detection method for reverse osmosis membrane fouling according to claim 7, characterized in that, The shielding step includes one or more of the following steps: Hydrochloric acid and scale inhibitor are continuously added to the influent until the pressure difference change exceeds the set range or / and the pressure difference reaches the set pressure difference threshold. Hydrochloric acid is continuously added to the influent until the pressure difference change exceeds the set range or / and the pressure difference reaches the set pressure difference threshold. Continuously add liquid alkali to the influent until the pressure difference change exceeds the set range or / and the pressure difference reaches the set pressure difference threshold. Sodium hypochlorite is continuously added to the influent until the pressure difference change exceeds the set range or / and the pressure difference reaches the set pressure difference threshold. Multiple filtrations are performed using filters until the differential pressure change exceeds the set range or / and the differential pressure reaches the set differential pressure threshold.

10. The online detection method for reverse osmosis membrane fouling according to claim 7, characterized in that, The steps for obtaining the contribution include: The contribution of each fouling factor is obtained using the following formula: in, For the first The contribution of each contamination factor; , These are flow rate weight and pressure difference weight, respectively. + =1; For the first The contribution of each fouling factor to flow attenuation. , For the first The permeate flow rate attenuation value within the detection period corresponding to each fouling factor. This represents the permeate flow rate attenuation value within the detection period corresponding to the total fouling factor. Contribution to the increase in pressure differential of fouling factors, , For the first The incremental value of differential pressure change within the detection cycle corresponding to each fouling factor. This represents the incremental value of the differential pressure change within the detection period corresponding to the total fouling factor.

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