Membrane pollution detection and cleaning method based on eluent

Abstract

The invention provides a membrane pollution detection and cleaning method based on eluent, and the detection method comprises the following steps: cleaning a target membrane, and collecting the eluent after cleaning in real time; detecting the total amount of organic matters in the eluent; measuring the absorbance of the eluent under a preset wavelength through a photometer so as to determine the structural characteristics of the organic matter; and detecting the fluorescence characteristics of the organic matters and the classification of the organic matters, and determining the parameters of the organic matters, meanwhile, determining inorganic element parameters in the eluent, and determining inorganic pollution parameters of the eluent according to the inorganic element parameters; performing multi-dimensional data fusion on the total amount of the organic matters, the structural characteristics, the parameters of the organic matters and the inorganic pollution parameters, and determining a membrane pollution result and a corresponding cleaning strategy; and cleaning the target film according to the cleaning strategy. According to the invention, the membrane pollution detection and cleaning precision can be improved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of membrane fouling, and more particularly to a membrane fouling detection and cleaning method based on eluent. BACKGROUND

[0002] With the continuous development of membrane technology and its wide application in various fields such as water treatment, chemical industry, pharmaceutical industry, etc., the problem of membrane fouling caused by membrane technology is increasingly prominent. Membrane fouling not only reduces the performance and service life of the membrane, but also increases the operating cost and maintenance difficulty. Therefore, accurately analyzing the causes and types of membrane fouling and developing effective cleaning strategies are crucial to ensure the stable operation of the membrane system.

[0003] Currently, the mainstream solution to the problem of membrane fouling is to continuously improve the accuracy and refinement of membrane fouling analysis, and to seek more efficient and environmentally friendly cleaning strategies. Common membrane fouling detection methods include direct observation of the membrane surface, measurement of membrane performance parameters, physical or chemical analysis of the membrane surface, and analysis of the membrane eluent.

[0004] However, these existing technologies have the following defects: 1. The method of direct observation of the membrane surface and measurement of the membrane performance parameters can only provide limited information, making it difficult to understand the nature and specific causes of membrane fouling. 2. The method of physical or chemical analysis of the membrane surface usually requires complex equipment and operation procedures, and may cause damage to the membrane. 3. The existing method of analyzing the membrane eluent is not comprehensive or accurate, and cannot accurately identify the types and sources of pollutants. 4. In terms of cleaning strategies, existing technologies often lack specificity and cannot develop personalized cleaning programs according to the specific types and degrees of membrane fouling, resulting in unsatisfactory cleaning results and even possible secondary damage to the membrane.

[0005] Therefore, in view of the many deficiencies of existing technologies in membrane fouling analysis and cleaning strategies, there is currently a need for a more comprehensive and accurate analysis method based on membrane eluent, combined with effective cleaning strategies, to meet the needs of practical applications and improve the operating efficiency and stability of the membrane system. SUMMARY

[0006] In view of the above problems, the present application aims to provide a membrane fouling detection and cleaning method based on eluent to solve the problems of complex operation, poor cleaning effect, and risk of secondary pollution in existing membrane fouling analysis and cleaning.

[0007] The membrane fouling detection method based on eluent provided by the present application comprises:

[0008] cleaning the target membrane and collecting the eluent after cleaning in real time;

[0009] detecting the total amount of the organic matter in the eluent by a TOC analyzer;

[0010] measuring the absorbance of the eluent at a preset wavelength by a photometer to determine the structural characteristics of the organic matter; and,

[0011] detecting the fluorescence characteristics of the organic matter by a three-dimensional fluorescence spectrum and analyzing the classification of the organic matter by a Fourier transform infrared spectrum, determining the parameters of the organic matter according to the fluorescence characteristics and the classification; and,

[0012] determining the inorganic element parameters in the eluent by an inductively coupled plasma mass spectrometer, and determining the inorganic pollution parameters of the eluent according to the inorganic element parameters;

[0013] performing multi-dimensional data fusion on the total amount of the organic matter, the structural characteristics, the parameters of the organic matter and the inorganic pollution parameters to determine the membrane pollution result and the corresponding cleaning strategy;

[0014] cleaning the target membrane according to the cleaning strategy and repeating the above steps until the pollution result meets the preset requirements.

[0015] In addition, the optional technical solution is that the parameters of the organic matter include the type, source and content of the organic matter; and the inorganic pollution parameters include the type, concentration and pollution degree of the inorganic elements.

[0016] In addition, the optional technical solution is that the eluent includes acid eluent and alkali eluent; wherein,

[0017] The cleaning strategy includes determining the type, concentration and cleaning time of the acid eluent and the alkali eluent, and determining the sequence of the acid eluent and the alkali eluent;

[0018] The acid eluent includes at least one of hydrochloric acid, sulfuric acid, nitric acid, fluoroboric acid and ferrous chloride with a concentration not less than 31%;

[0019] The alkali eluent includes at least one of sodium hydroxide, sodium carbonate, sodium bicarbonate, potassium hydroxide and sodium phosphate with a concentration not less than 30%.

[0020] In addition, the optional technical solution is that the photometer includes ultraviolet-visible spectrophotometer, infrared photometer, fluorescence photometer, atomic absorption photometer, double-beam photometer, single-beam photometer and flame photometer.

[0021] In addition, the optional technical solution is that the excitation wavelength range of the three-dimensional fluorescence spectrum is 200nm-450nm, the emission wavelength range of the three-dimensional fluorescence spectrum is 250nm-550nm, and the step is 5nm-10nm.

[0022] In addition, an optional technical solution is that, in the process of detecting the total amount of organic matter in the eluate by a TOC analyzer, the process includes:

[0023] The combustion temperature range of the TOC analyzer is 680°C to 720°C.

[0024] In addition, an optional technical solution is that, in the process of determining the inorganic element parameters in the eluent by inductively coupled plasma mass spectrometry, the process includes:

[0025] The radio frequency power range of the inductively coupled plasma mass spectrometer is 1200W to 1500W, and the flow rate range of the nebulizer in the inductively coupled plasma mass spectrometer is 0.8L / min to 1.0L / min.

[0026] In addition, an optional technical solution is that, in the process of analyzing the classification of the organic matter by Fourier transform infrared spectroscopy, the following steps are included:

[0027] The number of scans of the Fourier transform infrared spectrum ranges from 16 to 32 times, and the resolution range is 4 cm -1 ~8cm -1 .

[0028] In addition, an optional technical solution is that after the target membrane is cleaned according to the cleaning strategy, the membrane flux of the target membrane is monitored at a preset frequency, and the effectiveness of the cleaning strategy and the recovery of the target membrane are verified based on the membrane flux.

[0029] On the other hand, the present invention also provides a membrane cleaning method, which uses the above-mentioned membrane contamination detection method based on eluent to determine a cleaning strategy, and cleans the target membrane according to the cleaning strategy.

[0030] By utilizing the above-mentioned eluent-based membrane fouling detection and cleaning method, the membrane fouling situation can be obtained by analyzing the eluent, thereby optimizing the cleaning strategy and formulating a more targeted cleaning plan. This can not only improve the cleaning effect and effectively restore the performance of the membrane; but also timely discover the changes in membrane fouling through real-time analysis of the eluent, so as to take corresponding measures to achieve dynamic detection and cleaning, extend the service life of the membrane, reduce operating costs, and improve the stability and reliability of the membrane system.

[0031] In order to achieve the above and related purposes, one or more aspects of the present invention include the features that will be described in detail later. The following description and the accompanying drawings describe some exemplary aspects of the present invention in detail. However, these aspects indicate only some of the various ways in which the principles of the present invention can be used. In addition, the present invention is intended to include all of these aspects and their equivalents. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] Other objects and results of the present application will become more fully understood from the following description taken in conjunction with the accompanying drawings. In the drawings:

[0033] Figure 1 Flow chart of the eluate-based membrane fouling detection method according to an embodiment of the present application;

[0034] Figure 2 Organic matter concentration and proportion plot of the eluate according to an embodiment of the present application;

[0035] Figure 3 Organic matter proportion plot of the eluate according to an embodiment of the present application;

[0036] Figure 4 Organic matter proportion plot of the eluate of the acid washing after base washing according to an embodiment of the present application;

[0037] Figure 5 Three-dimensional fluorescence chromatogram of the eluate of the base washing after acid washing according to an embodiment of the present application;

[0038] Figure 6 Total inorganic element concentration plot of the eluate according to an embodiment of the present application;

[0039] Figure 7 Infrared spectrogram of the RO membrane and the fouled RO membrane according to an embodiment of the present application;

[0040] Figure 8 Membrane flux change plot according to an embodiment of the present application.

[0041] The same reference numbers in all the drawings indicate similar or corresponding features or functions. DETAILED DESCRIPTION

[0042] In the following description, for purposes of explanation, numerous specific details are set forth in order to provide a thorough understanding of one or more embodiments. It can be evident, however, that such embodiment(s) can be practiced without these specific details. In other instances, well-known structures and devices are shown in block diagram form in order to facilitate describing one or more embodiments.

[0043] It is to be understood that the singular forms "a," "an," and "the" include plural referents unless the context clearly dictates otherwise. It is further understood that the terms "comprise" (or comprise), "comprises" (or comprises) and "comprising" (or comprising), when used in this specification, specify the presence of stated features, integers, steps, operations, elements, or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, or groups thereof.

[0044] It is to be understood that the terms used herein are intended to have their common meanings unless defined otherwise. It is further understood that terms such as those defined in commonly used dictionaries should be interpreted as having a meaning that is consistent with their meaning in the context of the relevant art and will not be interpreted in an idealized or overly formal sense unless expressly so defined.

[0045] To solve the defects of the existing membrane pollution treatment scheme, for example, it is difficult to fully understand the nature of membrane pollution through membrane surface observation and simple tests, and it is difficult to accurately determine the composition and source of pollutants; the fixed cleaning program may not effectively remove specific types of pollutants, resulting in unsatisfactory cleaning effect, and frequent cleaning may cause secondary damage to the membrane; and lack of in-depth analysis of membrane eluent, which cannot optimize the cleaning strategy according to the characteristics of the pollutants, so as to maximize the performance of the membrane, etc., the present application provides a membrane pollution detection and cleaning method based on eluent, which can accurately determine the type and cause of membrane pollution based on comprehensive dynamic analysis of membrane eluent, so as to optimize the cleaning strategy, improve the cleaning effect, and prolong the service life of the membrane.

[0046] To describe the membrane pollution detection and cleaning method based on eluent of the present application in detail, the specific embodiments of the present application will be described in detail below in combination with the drawings.

[0047] Figure 1 The schematic flow of the membrane pollution detection method based on eluent according to the embodiment of the present application is shown.

[0048] As shown in Figure 1 The membrane pollution detection method based on eluent of the embodiment of the present application at least includes the following steps:

[0049] S100: cleaning treatment is performed on the target membrane, and the eluent after cleaning treatment is collected in real time.

[0050] The target membrane is cleaned by a preset membrane eluent (referred to as eluent). In the membrane pollution detection process, the sample to be analyzed is the eluent after the target membrane is cleaned. The eluent can be a reverse osmosis membrane eluent.

[0051] In addition, to ensure the accuracy of the detection, the eluent collected for analysis is stored in a sterile container, such as a high-temperature sterilization, chemical sterilization, or filtration sterilization. As a specific example, the container is subjected to high-temperature sterilization before collection, and the sterilization temperature can be set to 121°C, and the sterilization time is 15-20 minutes, thereby ensuring that the eluent is not contaminated by the outside world and ensuring the accuracy of subsequent detection.

[0052] S200: Detecting the total amount of organic matter in the eluent by a TOC analyzer.

[0053] The TOC analyzer (Total Organic Carbon, referred to as TOC) is an instrument for analyzing total organic carbon. It mainly uses the content of carbon to represent the total amount of organic matter in water. It can be directly used to represent the total amount of organic matter.

[0054] Specifically, the total amount of organic matter in the eluent is detected by a TOC analyzer, which can use a combustion method or a photocatalytic method. If the combustion method is used, the combustion temperature of the TOC analyzer can be controlled between 680°C and 720°C to completely oxidize the organic matter and determine the total amount of organic matter in the eluent.

[0055] S300: Measuring the absorbance of the eluent at a preset wavelength by a photometer to determine the structural characteristics of the organic matter.

[0056] The photometer includes ultraviolet-visible spectrophotometer, infrared photometer, fluorescence photometer, atomic absorption photometer, double-beam photometer, single-beam photometer, and flame photometer. When the ultraviolet-visible spectrophotometer (UV-Vis) is used to measure the absorbance, the optical path of the cuvette can be selected to be 1cm to 2cm, and the preset wavelength can be set to 254nm to reflect the aromaticity and double bond structure of the organic matter, thereby ensuring the accuracy and sensitivity of the measurement. It can be seen that the specific type of photometer and the preset wavelength can be flexibly set according to the application scenario and detection requirements.

[0057] S400: Detecting the fluorescence characteristics of the organic matter by three-dimensional fluorescence spectroscopy, and analyzing the classification of the organic matter by Fourier transform infrared spectroscopy, and determining the parameters of the organic matter according to the fluorescence characteristics and the classification.

[0058] The three-dimensional fluorescence spectrum (3D-EEM) is a matrix spectrum represented by three-dimensional coordinates of excitation wavelength, emission wavelength and fluorescence intensity, also called total luminescence spectrum. The three-dimensional fluorescence spectrum can determine the fluorescence intensity information of the organic matter in the eluent, which is metabolized by microorganisms. The Fourier transform infrared spectrum is used to analyze the classification of the organic matter. The scanning times of the Fourier transform infrared spectrum can be set to 16 to 32 times, and the resolution range can be set to 4cm -1 ~ 8cm -1 Finally, the parameters of the organic matter are determined by the fluorescence characteristics and classification, including the type, source and content of the organic matter.

[0059] As a specific example, the excitation wavelength range of the three-dimensional fluorescence spectrum can be set to 200nm to 450nm, and the emission wavelength range of the three-dimensional fluorescence spectrum can be set to 250nm to 550nm, with a step of 5nm to 10nm, thereby improving the accuracy of detection.

[0060] S500: Determine the inorganic element parameters in the eluent by inductively coupled plasma mass spectrometer, and determine the inorganic pollution parameters of the eluent according to the inorganic element parameters.

[0061] When the inductively coupled plasma mass spectrometer (ICP-MS) is used to determine the inorganic element concentration, the radio frequency power can be set to 1200W to 1500W, and the flow rate of the atomizer in the inductively coupled plasma mass spectrometer can be set to 0.8L / min to 1.0L / min. The inorganic pollution parameters include the type (such as Ca, Al, Si, Fe, Mn, Mg, etc.), concentration and pollution degree of inorganic elements.

[0062] S600: Multi-dimensional data fusion is performed on the total amount of organic matter, structural characteristics, parameters of organic matter and inorganic pollution parameters to determine the membrane pollution result and the corresponding cleaning strategy.

[0063] The total amount of organic matter, structural characteristics, parameters of organic matter and inorganic pollution parameters can be fused at least twice to determine the relevant information of membrane pollution, and then the corresponding cleaning strategy is determined according to the final determined pollution result.

[0064] Specifically, the total amount of organic matter detected by the TOC analyzer and the absorbance data measured by UV-Vis can be verified together to represent the pollution characteristics of organic matter; the microbial metabolic products identified by 3D-EEM, combined with the inorganic element concentration detected by ICP-MS, can infer the pollution type, such as biological pollution, coexistence of biological pollution and inorganic scaling, etc. By jointly analyzing the functional groups and fluorescence characteristics of organic matter by FTIR and 3D-EEM, and evaluating the proportion of inorganic / organic pollution by ICP-MS and UV-Vis, the pollution cause can be finally determined through multi-dimensional data fusion.

[0065] Among them, the common types of organic matter mainly include polysaccharides, proteins, humic acid, oils and synthetic organic matter, etc., and the structural characteristics of organic matter include hydrophilicity / hydrophobicity, molecular weight distribution and functional group analysis, such as hydroxyl, carboxyl, which indicates polysaccharides or humic acid, and amino indicates protein pollution, etc.; the types of inorganic pollution can include crystallinity, colloidal type and silicon scale, etc., and the microbial pollution is mainly reflected in the amount of extracellular polymeric substance and viable bacteria.

[0066] When performing multi-dimensional data fusion on the above detection data, the principal component analysis method can be used to reduce the dimension of the data and identify the dominant pollution factors; or clustering analysis can be performed to divide the types of pollution, such as organic type, inorganic type or mixed type, etc., and a classification model can be trained through historical data for machine learning to determine the type of pollution, and accordingly determine the membrane pollution result.

[0067] When determining the cleaning strategy according to the membrane pollution result, the eluent can include acid washing solution, alkali washing solution, enzyme cleaning, oxidation cleaning, surfactant, etc.; wherein the cleaning strategy includes: determining the type of eluent, the cleaning sequence, and the concentration of eluent and other related parameters, in one specific embodiment of the present application, the type, concentration and cleaning time of acid washing solution and alkali washing solution can be determined according to the type of membrane pollution, and the sequence of acid washing solution and alkali washing solution can be determined; wherein the acid washing solution includes at least one of hydrochloric acid, sulfuric acid, nitric acid, fluoroboric acid and ferrous chloride with a concentration not less than 31%; and the alkali washing solution includes at least one of sodium hydroxide, sodium carbonate, sodium bicarbonate, potassium hydroxide and sodium phosphate with a concentration not less than 30%.

[0068] S700: According to the cleaning strategy, the target membrane is cleaned and the above steps are repeatedly executed until the pollution result meets the preset requirement.

[0069] In this step, after determining the cleaning strategy, the target membrane is cleaned using the strategy, and the above steps are repeatedly performed until the membrane fouling result meets the preset requirement. In this process, the eluate after cleaning treatment can be collected in real time, and through dynamic detection and analysis, an effective cleaning strategy is determined, and then the cleaned membrane is verified, for example, the membrane flux of the target membrane is monitored according to a preset frequency, for example, the measurement time interval is 10-30 minutes, and the membrane flux is continuously monitored for at least 2 hours to verify the effectiveness of the cleaning strategy and the recovery of the target membrane.

[0070] In addition, in the eluate-based membrane fouling cleaning method of the embodiment of the present application, other analysis methods or instruments can also be added, such as a gas chromatography-mass spectrometer (GC-MS) and the like, to more comprehensively understand the composition of the pollutants.

[0071] As a specific example, the reverse osmosis membrane system of a water treatment plant of a certain steel plant is selected for experiment. After the system runs for a period of time, the phenomenon of membrane flux decline occurs, and it is suspected that there is membrane fouling. The system is treated by using the eluate-based membrane fouling cleaning method of the embodiment of the present application.

[0072] Firstly, real-time collection of membrane eluate is performed. After the alkali washing and acid washing steps, the eluate is collected using sterile containers respectively, and it is ensured that the containers are subjected to 121℃ high-temperature sterilization treatment for 15-20 minutes before use.

[0073] Then, the eluate is analyzed. A TOC analyzer is used to measure the total organic carbon (TOC) content, and the combustion temperature of the TOC instrument is set to 700℃. At the same time, a UV-visible spectrophotometer is used to measure the absorbance at a wavelength of 254nm, and the optical path of the cuvette is selected to be 1cm.

[0074] At the same time, three-dimensional fluorescence spectrum detection is performed, and the excitation wavelength range is set to 200-450nm, and the emission wavelength range is set to 250-550nm, both with a step of 5nm. When the inductively coupled plasma mass spectrometer is used to measure the inorganic element concentration, the radio frequency power is set to 1300W, and the atomizer flow rate is 0.9L / min. When the Fourier transform infrared spectrum is used to analyze the organic components, the scanning number is set to 24, and the resolution is 6cm -1 .

[0075] Then, when monitoring the membrane flux, the measurement time interval is 20 minutes, and the membrane flux is continuously monitored for 3 hours. The specific analysis results are shown in FIGS. 1-3. Figure 2 Figure 8

[0076] Figure 2 Figure 3 ​​​​The organic matter concentration and proportion chart can see that the total organic carbon (TOC) and UV content in the eluent after alkaline cleaning is higher, indicating that the organic matter pollution is more serious. In addition, the total concentration of organic matter in the eluent after acid cleaning and then alkaline cleaning is higher than that in the eluent after alkaline cleaning and then acid cleaning, which shows that in the cleaning process, the method of acid cleaning and then alkaline cleaning is more conducive to the cleaning of organic matter on the RO membrane. 254 The total concentration of organic matter in the eluent after acid cleaning and then alkaline cleaning is higher than that in the eluent after alkaline cleaning and then acid cleaning, which shows that in the cleaning process, the method of acid cleaning and then alkaline cleaning is more conducive to the cleaning of organic matter on the RO membrane.

[0077] From the three-dimensional fluorescence chromatogram of Figure 4 and Figure 5 It can be seen that whether it is acid cleaning or alkaline cleaning, the organic matter in the eluent is mainly aromatic protein substances and dissolved microbial metabolites, which shows that during the long-term operation of the RO, microorganisms grow on the membrane surface, and the microorganisms affect the operation of the RO membrane.

[0078] From the total concentration chart of inorganic elements of Figure 6 It can be seen that there are certain concentrations of calcium, aluminum, silicon, magnesium, iron and manganese elements in the eluent, which shows that the inorganic pollution of the membrane cannot be ignored. In addition, the total concentration of inorganic elements in the eluent after acid cleaning and then alkaline cleaning is slightly higher than that in the eluent after alkaline cleaning and then acid cleaning, that is, the cleaning method of acid cleaning and then alkaline cleaning is more conducive to the removal of inorganic elements on the RO membrane.

[0079] From the infrared spectrum of Figure 7 It can be seen that there are specific absorption peaks in the infrared spectra of the RO membranes after different cleaning methods and the contaminated RO membrane. For example, the absorption peak at 1650 cm -1 indicates the existence of C=O and C=C bonds, and the absorption peak at 1050 cm -1 indicates the existence of C-O-C bonds. The existence of these absorption peaks further confirms the existence of organic and inorganic pollutants on the membrane surface. By comparing the spectra of the RO membranes after different cleaning methods, it can be found that the method of acid cleaning and then alkaline cleaning can more effectively remove some specific pollutants, so that the spectral characteristics of the RO membrane are closer to the original un-contaminated state.

[0080] From the membrane flux change chart of Figure 8 It can be seen that the membrane flux of the contaminated RO membrane is low, and after the cleaning method of acid cleaning and then alkaline cleaning, the membrane flux has been significantly improved and is close to the flux level of the original un-contaminated membrane; while the method of alkaline cleaning and then acid cleaning, the recovery degree of the membrane flux is relatively low. This shows that the cleaning method of acid cleaning and then alkaline cleaning has an advantage in restoring the performance of the RO membrane.

[0081] In summary, the Figures 2 to 8According to the analysis results, the cleaning mode of acid washing followed by alkali washing has better performance in removing organic matters and inorganic elements and restoring the performance of the RO membrane.

[0082] It can be known that the membrane pollution cleaning method based on eluent can realize dynamic detection and feedback by combining the monitoring of membrane flux and the analysis of pollutants, form a closed loop of analysis-cleaning-verification, evaluate the membrane pollution from different angles, verify the effectiveness of the cleaning strategy and the recovery of the membrane performance according to the monitoring results of the membrane flux, and comprehensively understand the type, cause and composition of the pollutants, so as to more accurately judge the membrane pollution and solve the problems of lack of pertinence and effectiveness of the existing cleaning strategy.

[0083] Corresponding to the above-mentioned membrane pollution cleaning method based on eluent, the application further provides a membrane cleaning method, which determines a cleaning strategy by using the above-mentioned membrane pollution detection method based on eluent, and cleans the target membrane according to the cleaning strategy.

[0084] It should be noted that the embodiments of the above-mentioned membrane cleaning method based on eluent and the embodiments of the membrane pollution detection method based on eluent can be mutually referenced, and will not be described one by one here.

[0085] According to the above-mentioned membrane pollution detection and cleaning method based on eluent, the specific conditions of the membrane pollution are obtained by analyzing the eluent through multiple ways, so as to optimize the cleaning strategy and develop a more targeted cleaning scheme, which not only can improve the cleaning effect and effectively restore the performance of the membrane, but also can discover the change of the membrane pollution in time through real-time analysis of the eluent, realize dynamic detection and effective cleaning, reduce the cleaning cost, prolong the service life of the membrane, improve the stability and reliability of the membrane system, and be applicable to the membrane technology in various fields.

[0086] The membrane pollution detection and cleaning method based on eluent according to the application is described above with reference to the accompanying drawings in an exemplary manner. However, those skilled in the art should understand that various improvements can be made to the above-mentioned membrane pollution detection and cleaning method based on eluent without departing from the content of the application. Therefore, the protection scope of the application should be determined by the content of the appended claims.

Claims

1. A membrane fouling detection method based on eluent, characterized in that: include: Cleaning the target membrane and collecting the eluate after cleaning in real time; Detecting the total amount of organic matter in the eluate by a TOC analyzer; Measuring the absorbance of the eluate at a preset wavelength using a photometer to determine the structural characteristics of the organic matter; as well as, The fluorescence characteristics of the organic matter are detected by three-dimensional fluorescence spectroscopy, and the classification of the organic matter is analyzed by Fourier transform infrared spectroscopy, and the parameters of the organic matter are determined according to the fluorescence characteristics and the classification; at the same time, Determining inorganic element parameters in the eluate by inductively coupled plasma mass spectrometry, and determining inorganic contamination parameters of the eluate based on the inorganic element parameters; Performing multi-dimensional data fusion on the total amount of the organic matter, the structural characteristics, the parameters of the organic matter, and the inorganic pollution parameters to determine the membrane pollution result and the corresponding cleaning strategy; The target membrane is cleaned according to the cleaning strategy and the above steps are repeated until the contamination result meets the preset requirements.

2. The membrane fouling detection method based on eluent according to claim 1, characterized in that The parameters of the organic matter include the type, source and content of the organic matter; The inorganic pollution parameters include the type, concentration and pollution degree of inorganic elements.

3. The membrane fouling detection method based on eluent according to claim 1, characterized in that The eluent includes an acid wash solution and an alkaline wash solution; wherein, The cleaning strategy includes: determining the type, concentration, and cleaning time of the acid cleaning solution and the alkaline cleaning solution, and determining the order of the acid cleaning solution and the alkaline cleaning solution; The pickling solution comprises at least one of hydrochloric acid, sulfuric acid, nitric acid, fluoroboric acid and ferrous chloride with a concentration of not less than 31%; The alkaline washing solution includes at least one of sodium hydroxide, sodium carbonate, sodium bicarbonate, potassium hydroxide and sodium phosphate with a concentration of not less than 30%.

4. The membrane fouling detection method based on eluent according to claim 1, characterized in that The photometer includes an ultraviolet-visible spectrophotometer, an infrared photometer, a fluorescence photometer, an atomic absorption photometer, a double-beam photometer, a single-beam photometer, and a flame photometer.

5. The membrane fouling detection method based on eluent according to claim 1, characterized in that: The excitation wavelength range of the three-dimensional fluorescence spectrum is 200nm to 450nm, the emission wavelength range of the three-dimensional fluorescence spectrum is 250nm to 550nm, and the step length is 5nm to 10nm.

6. The membrane fouling detection method based on eluent according to claim 1, characterized in that: In the process of detecting the total amount of organic matter in the eluate by a TOC analyzer, The combustion temperature range of the TOC analyzer is 680°C to 720°C.

7. The membrane fouling detection method based on eluent according to claim 1, characterized in that: In the process of determining the inorganic element parameters in the eluent by inductively coupled plasma mass spectrometry, The radio frequency power range of the inductively coupled plasma mass spectrometer is 1200W to 1500W, and the flow rate range of the nebulizer in the inductively coupled plasma mass spectrometer is 0.8L / min to 1.0L / min.

8. The membrane fouling detection method based on eluent according to claim 1, characterized in that: In the process of analyzing the classification of the organic matter by Fourier transform infrared spectroscopy, The number of scans of the Fourier transform infrared spectrum ranges from 16 to 32 times, and the resolution range is 4 cm -1 ~8cm -1 .

9. The membrane fouling detection method based on eluent according to claim 1, characterized in that: After the target film is cleaned according to the cleaning strategy, the method further comprises: The membrane flux of the target membrane is monitored at a preset frequency, and the effectiveness of the cleaning strategy and the recovery of the target membrane are verified based on the membrane flux.

10. A membrane cleaning method, characterized in that: A cleaning strategy is determined using the membrane fouling detection method based on the eluent according to any one of claims 1 to 9, and the target membrane is cleaned according to the cleaning strategy.

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