A magnetic coagulation-ultrafiltration membrane wastewater treatment magnetic floc state and membrane pollution on-line monitoring system and method

Abstract

The application discloses a kind of magnetic coagulation-ultrafiltration membrane wastewater treatment in magnetic floc state and membrane pollution on-line monitoring system and method, it relates to a kind of physical property measurement technical field, based on the quality index of floc that obtains floc based on the depolarization ratio and magnetic floc diameter, simultaneously through the transmembrane pressure difference and flux parameter obtains membrane state parameter, realizes the synchronous quantification of magnetic floc physical characteristics and membrane operating state, through the dynamic evaluation of floc quality index and membrane state parameter, the abnormal phenomenon of simultaneous perception membrane pollution specific situation that the compactness of magnetic floc is reduced or particle size deviates is accurately identified, the data correlation analysis of floc quality and membrane pollution state can reveal the potential influence mechanism of floc characteristics to membrane pollution, so as to adjust signal synchronous optimization coagulation condition and membrane cleaning strategy, solve the problem of water quality reduction and membrane damage caused by monitoring lag in the prior art.

Description

Technical Field

[0001] This invention relates to the field of physical property measurement technology, and more particularly to an online monitoring system and method for the state of magnetic flocs and membrane fouling in magnetic coagulation-ultrafiltration membrane wastewater treatment. Background Technology

[0002] Magnetic coagulation sedimentation technology is a highly efficient water treatment enhancement process. Its core lies in adding micron-sized magnetic powder as a coagulation nucleus carrier to the coagulation system. Through the microcrystalline nucleation effect and surface adsorption of the magnetic powder, the density of the coagulated flocs is significantly increased, their structure becomes more compact, and they are endowed with ferromagnetism. Subsequently, a high-gradient magnetic separator is used to rapidly capture and separate the magnetic flocs from the solids, thereby greatly improving the settling rate and pollutant removal efficiency. It is particularly suitable for high-standard phosphorus removal, deep turbidity removal, and compact wastewater treatment scenarios.

[0003] Magnetic coagulation, as a highly efficient pretreatment unit, can remove most suspended solids, colloids, and phosphorus. However, its effluent may still contain submicron-sized fine particles, unprecipitated light flocs, and dissolved organic matter. Ultrafiltration membranes, acting as a precision barrier, achieve near-absolute physical sieving through their micropores, completely trapping the aforementioned residual pollutants, as well as all bacteria and viruses. This significantly reduces turbidity and SDI values, resulting in stable, biologically safe reclaimed water and providing perfect feed conditions for potential subsequent reverse osmosis treatment.

[0004] If the effluent from magnetic coagulation is not properly controlled, the residual trace magnetic powder, broken flocs, and excessive coagulant can seriously damage the subsequent membrane system. Current technologies rely on manual, intermittent sampling to detect water quality indicators, which has a significant time lag and cannot capture sudden changes in water quality in real time. This monitoring blind spot prevents timely adjustments to the coagulant dosage or magnetic powder recovery efficiency, causing substandard water to continuously enter the membrane system. This leads to irreversible blockage of membrane pores, surface scratches, and chemical contamination, ultimately resulting in flux decline and a sharp reduction in membrane lifespan.

[0005] Therefore, it is necessary to improve the existing online wastewater detection methods to solve the above problems. Summary of the Invention

[0006] This invention overcomes the shortcomings of the prior art and provides an online monitoring system and method for the state of magnetic flocs and membrane fouling in magnetic coagulation-ultrafiltration membrane wastewater treatment, aiming to solve the problems of reduced water quality and membrane damage caused by monitoring lag in the prior art.

[0007] To achieve the above objectives, the technical solution adopted by this invention is: an online monitoring method for the state of magnetic flocs and membrane fouling in magnetic coagulation-ultrafiltration membrane wastewater treatment, comprising: S1: Obtain the polarization intensity parameters of the magnetic flocculant, calculate the depolarization ratio, and obtain the polarization structure state parameters of the magnetic flocculant; S2: Obtain the light intensity signal parameters at 135° and 30° scattering angles of the magnetic floc, calculate the diameter of the magnetic floc, and obtain the magnetic floc diameter state parameters; use the magnetic floc polarization structure state parameters and the magnetic floc diameter state parameters to calculate the floc mass index; S3: Obtain the transmembrane pressure difference and flux parameters of the ultrafiltration membrane, calculate the membrane state parameters, and obtain the membrane state parameters; S4: Compare the floc mass index with the mass threshold and the membrane state parameter with the membrane state threshold respectively, and generate the mass adjustment signal and the membrane state adjustment signal respectively; S5: Optimize the treated wastewater using the quality adjustment signal and the membrane state adjustment signal.

[0008] In a preferred embodiment of the present invention, the polarization intensity parameters of the magnetic flocculant include a vertical detection parameter and a parallel detection parameter, the depolarization ratio is the ratio of the vertical detection parameter to the parallel detection parameter, and the polarization structure state parameter P of the magnetic flocculant exists in the following relationship: Where I1 is the vertical detection parameter and I2 is the parallel detection parameter.

[0009] In a preferred embodiment of the present invention, the relationship d between the light intensity signal parameters at 135° and 30° scattering angles of the magnetic flocs and the particle size of the magnetic flocs is as follows: Where I3 is the light intensity parameter at a 135° scattering angle, I4 is the light intensity parameter at a 30° scattering angle, and k is the calibration coefficient with a value range of 0.1-1.0.

[0010] In a preferred embodiment of the present invention, the magnetic floc diameter state parameter is determined based on the average diameter parameter and the diameter deviation parameter. The average diameter parameter is the average value of the magnetic floc diameter, and the diameter deviation parameter is the standard deviation of the magnetic floc diameter. The magnetic floc diameter state parameter D has a relationship. D a For diameter average parameters, This is the diameter deviation parameter.

[0011] In a preferred embodiment of the present invention, the floc mass index F has the following relationship: .

[0012] In a preferred embodiment of the present invention, the transmembrane pressure difference T has a relationship ,in For the inlet side pressure, The pressure on the outlet side; the membrane state parameter M has a relationship. ,in The viscosity of the inlet fluid is denoted as , where This represents the inherent resistance of the membrane.

[0013] In a preferred embodiment of the present invention, both the floc mass threshold and the membrane state threshold are preset values, determined based on past data; the mass adjustment signal is a coagulant dosage control signal and a magnetic powder dosage increase signal, and the membrane state adjustment signal is a membrane surface cleaning signal and a membrane flux reduction signal.

[0014] In a preferred embodiment of the present invention, when the quality of flocs is substandard, a coagulant dosage control signal, a magnetic powder dosage control signal, and a membrane surface cleaning signal are generated. The coagulant dosage control signal is used to increase the coagulant dosage. After optimization, monitoring continues. If the floc quality and membrane condition still do not meet the standards, a coagulant dosage control signal and a membrane flux reduction signal are generated. The coagulant dosage control signal is used to reduce the coagulant dosage.

[0015] In a preferred embodiment of the present invention, when the floc condition meets the standard but the membrane condition does not meet the standard, a membrane surface cleaning signal and a membrane flux reduction signal are generated; when the floc condition meets the standard and the membrane condition meets the standard, no quality adjustment signal and membrane condition adjustment signal are generated.

[0016] To achieve the above objectives, the second technical solution adopted by this invention is: an online monitoring system for the state of magnetic flocs and membrane fouling in magnetic coagulation-ultrafiltration membrane wastewater treatment, comprising: A polarized light transmitting and receiving unit is used for transmitting and receiving polarized light signals. The scattered light transmitting and receiving unit is used for transmitting and receiving light intensity signals at 135° and 30° respectively, for the transmission of unpolarized light; Depolarization ratio calculation unit, used to receive polarized light signals and calculate depolarization ratio; The particle size calculation unit is used to receive light intensity signals and calculate the diameter of the magnetic flocs; The floc mass calculation unit is used to calculate the floc mass index. The membrane state detection unit is used to acquire the transmembrane pressure difference and flux parameters of the ultrafiltration membrane; Membrane state calculation unit, used to calculate membrane state parameters; The floc quality comparison unit is used to compare the floc quality index with the quality threshold. The membrane state comparison unit is used to compare membrane state parameters with membrane state thresholds. The discrimination unit is used to determine the quality of flocs and the condition of the membrane. The signal generation unit is used to generate quality adjustment signals and membrane state adjustment signals; The execution unit is used to execute quality adjustment signals and membrane state adjustment signals; A transmission unit is used to transmit data.

[0017] This invention addresses the shortcomings of the prior art and has the following beneficial effects: This invention provides an online monitoring method for magnetic floc state and membrane fouling in magnetic coagulation-ultrafiltration membrane wastewater treatment. Based on the descaling ratio and magnetic floc diameter, the method obtains the floc quality index, while simultaneously acquiring membrane state parameters through transmembrane pressure difference and flux parameters. This achieves synchronous quantification of the physical properties of magnetic flocs and the membrane operating state. Compared to existing online monitoring systems and methods for magnetic floc state and membrane fouling, this method, through dynamic evaluation of the floc quality index and membrane state parameters, accurately identifies abnormal phenomena such as decreased magnetic floc density or particle size deviation, while simultaneously sensing the specific situation of membrane fouling. Data correlation analysis between floc quality and membrane fouling state reveals the potential impact mechanism of floc characteristics on membrane fouling. Therefore, by adjusting signals synchronously optimizing coagulation conditions and membrane cleaning strategies, this method solves the problems of reduced water quality and membrane damage caused by monitoring lag in existing technologies.

[0018] In this invention, when the quality of the flocs does not meet the standards, the system simultaneously generates signals for increasing the amount of coagulant added, adjusting the amount of magnetic powder added, and cleaning the membrane surface. This allows for simultaneous intervention from both the source of floc formation and the control of membrane fouling. Compared with existing technologies, this invention improves the floc structure and particle size by strengthening coagulation and supplementing with magnetic powder, and reduces the accumulation of pollutants by cleaning the membrane surface in a timely manner. This avoids the limitations of single adjustment methods and achieves rapid response and synergistic optimization in problem handling.

[0019] In this invention, the simultaneous quantification of floc structure order and particle size distribution is achieved through online polarization depolarization ratio detection and multi-angle scattered light intensity analysis, which can accurately distinguish floc state. Compared with existing technologies, it avoids the timeliness deviation of offline detection. Combined with online monitoring of transmembrane pressure difference and membrane flux, it reflects the degree of membrane fouling in real time. The type of fouling is judged by the correlation change of transmembrane pressure difference and flux, providing a basis for targeted adjustment and improving the accuracy and timeliness of real-time monitoring. Attached Figure Description

[0020] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments recorded in the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort. Figure 1 This is a flowchart illustrating the method steps of a preferred embodiment of the present invention; Figure 2 This is a schematic diagram of a polarized light transmitting and receiving unit according to a preferred embodiment of the present invention; Figure 3 This is a schematic diagram of a scattered light transmitting and receiving unit according to a preferred embodiment of the present invention. Detailed Implementation

[0021] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0022] Many specific details are set forth in the following description in order to provide a full understanding of the invention. However, the invention may also be practiced in other ways different from those described herein. Therefore, the scope of protection of the invention is not limited to the specific embodiments disclosed below.

[0023] Application Overview: In existing technologies, the magnetic coagulation-ultrafiltration membrane wastewater treatment process often suffers from membrane fouling due to improper control of the physical properties of the magnetic flocs. If the floc particle size is too small or unevenly distributed, fine particles can easily penetrate the membrane pores and accumulate inside the membrane, causing irreversible blockage. Conversely, excessively large particle sizes can lead to a loose filter cake structure, increasing local pressure on the membrane surface and accelerating fouling. Insufficient floc density results in a loose structure and increased porosity, which not only reduces settling efficiency but also makes the flocs prone to breakage under shear force, releasing pollutants. These residues enter the ultrafiltration membrane system with the effluent, adhering to the membrane surface and forming a fouling layer, ultimately exacerbating membrane flux decline and chemical damage. Existing technologies lack real-time quantitative methods for floc characteristics, making it impossible to adjust coagulation conditions in a timely manner. Consequently, it is difficult to maintain highly dense flocs of suitable size, resulting in a persistent risk of membrane fouling.

[0024] Unexpectedly, it was discovered that highly dense flocs, with their compact structure and smooth surface, effectively reduce contaminant adhesion and membrane pore blockage. Meanwhile, flocs with uniform particle size facilitate the formation of a stable and permeable filter cake layer, reducing filtration resistance. Conversely, loose or abnormally sized flocs increase fluid resistance and release secondary contaminants. These changes can indirectly reflect the degree of membrane fouling through parameters such as transmembrane pressure difference and flux. By monitoring floc quality online, the system can detect the potential impact of abnormal floc conditions on membrane fouling in advance, achieving early warning at the source, rather than relying on delayed water quality testing. This establishes a direct correlation mechanism between floc characteristics and membrane condition.

[0025] By assessing floc quality in real time, the system can generate adjustment signals to optimize the addition of coagulants and magnetic powder, promoting the formation of ideal flocs with appropriate size and dense structure. This reduces the migration of pollutants to the membrane system at the source, enabling operators to accurately determine the type of fouling and implement targeted measures, such as enhanced coagulation or membrane cleaning. This avoids the waste of resources caused by blind adjustments, not only improving the stability of effluent water quality but also significantly reducing the frequency of membrane fouling, extending the service life of membrane modules, and enhancing the economy and reliability of the overall process.

[0026] like Figure 1 As shown, an online monitoring method for the state of magnetic flocs and membrane fouling in magnetic coagulation-ultrafiltration membrane wastewater treatment includes: S1: Obtain the polarization intensity parameters of the magnetic flocculant, calculate the depolarization ratio, and use the depolarization ratio as the polarization structure state parameter of the magnetic flocculant. S2: Obtain the light intensity signal parameters at 135° and 30° scattering angles of the magnetic floc, calculate the diameter of the magnetic floc, and obtain the diameter state parameters of the magnetic floc; use the polarization structure state parameters and the diameter state parameters of the magnetic floc to calculate the floc mass index; S3: Obtain the transmembrane pressure difference and flux parameters of the ultrafiltration membrane, calculate the membrane state, and obtain the membrane state parameters; S4: Compare the floc mass index with the mass threshold and the membrane state parameter with the membrane state threshold respectively, and generate the mass adjustment signal and the membrane state adjustment signal respectively; S5: Optimize the treated wastewater using quality adjustment signals and membrane state adjustment signals. Continue monitoring after optimization until the floc mass index meets the quality threshold and the membrane state parameters meet the membrane state threshold during the monitoring process.

[0027] The steps will be described in detail below: In step S1, the polarization structure parameters of the magnetic floc are obtained, specifically its density.

[0028] A linearly polarized laser source is used as the incident light, ensuring that the polarization direction is perpendicular to the detection plane. A transparent detection window is set in the magnetic coagulation reaction zone, allowing the laser beam to penetrate the magnetic floc suspension perpendicularly. A polarizer is placed behind the detection window, and the transmitted light intensity is measured at different angles by rotating the analyzer. The depolarization ratio reflects the magnetic floc's ability to scatter polarized light. If the floc's internal structure is dense, the polarization direction of the scattered light changes little, resulting in a low depolarization ratio; if the structure is loose, the polarization direction of the scattered light is randomized, resulting in a high depolarization ratio.

[0029] In step S2, the particle size distribution of the magnetic flocs is quantitatively analyzed to provide particle size information for floc quality assessment.

[0030] The magnetic floc suspension was irradiated with a non-polarized light source. Two photodetectors were placed behind the detection window and fixed at scattering angles of 135° and 30°, respectively. The 135° scattering angle was sensitive to small-diameter flocs, and the 30° scattering angle was sensitive to large-diameter flocs, covering the typical particle size range of magnetic flocs. The stable light intensity value could characterize the floc diameter.

[0031] The floc quality index is calculated using the polarization structure state parameters and diameter state parameters of the magnetic flocs. These parameters are then used to comprehensively analyze both floc density and diameter to assess floc quality, which in turn affects membrane fouling in subsequent treatment processes.

[0032] In step S3, the degree of membrane fouling is quantified by membrane filtration performance parameters to determine the impact of floc quality on membrane fouling.

[0033] In step S4, a threshold judgment is used to trigger process adjustment and determine the direction of adjustment.

[0034] By judging the threshold, it is determined whether the floc quality and membrane fouling requirements during the monitoring process meet the standards, and adjustments are made accordingly based on the results.

[0035] In step S5, the process parameters are adjusted according to the direction of adjustment so that the floc quality index meets the quality threshold and the membrane state parameters meet the membrane state threshold, thereby achieving the two indicators of floc quality compliance and good membrane fouling status.

[0036] The online monitoring methods will be explained in detail below: The polarization intensity parameters of the magnetic floc include vertical detection parameters and parallel detection parameters. The depolarization ratio is the ratio of the vertical detection parameter to the parallel detection parameter. The polarization structure state parameter P of the magnetic floc exists in the following relationship: Where I1 is the vertical detection parameter and I2 is the parallel detection parameter.

[0037] In the detection of the polarization structure of magnetic flocs, the perpendicular detection parameter and the parallel detection parameter are the core physical quantities used to quantify the scattering characteristics of magnetic flocs on polarized light. The perpendicular detection parameter refers to the intensity of transmitted light when the polarization direction of the analyzer is perpendicular to the polarization direction of the incident light, while the parallel detection parameter refers to the intensity of transmitted light when the polarization direction of the analyzer is parallel to the incident light. The depolarization ratio is defined as the ratio of the two, reflecting the depolarization ability of the magnetic flocs on polarized light, that is, the degree to which the internal structure changes the polarization state of light.

[0038] A low depolarization ratio indicates that the flocs are dense with few pores, resulting in minimal change in the polarization direction of the scattered light. The intensity of the perpendicularly transmitted light is much lower than that in the parallel direction. Conversely, a high depolarization ratio indicates that the flocs are loose with many pores, resulting in randomized polarization of the scattered light. The intensity of the perpendicularly and parallel transmitted light is close. During detection, a linearly polarized laser should be used as the light source to ensure that the polarization direction of the incident light is perpendicular to the detection plane. The magnetic floc suspension should be contained in a transparent sample cell. The analyzer should be rotated to 0° and 90° to record the light intensity. Repeated measurements should be taken and averaged to reduce noise.

[0039] The relationship between depolarization ratio and magnetic floc structure can be explained by Mie scattering theory and fractal theory. Dense flocs are mainly surface reflective with small polarization changes, while loose flocs are mainly volume scattering with randomized polarization. The higher the fractal dimension, the lower the depolarization ratio. This method provides a key monitoring means for the optimization of magnetic coagulation-ultrafiltration membrane systems through non-destructive, real-time polarized light detection.

[0040] The relationship between the light intensity signal parameters of the magnetic floc at 135° and 30° scattering angles and the particle size of the magnetic floc is d. Where I3 is the light intensity parameter at a 135° scattering angle, I4 is the light intensity parameter at a 30° scattering angle, and k is the calibration coefficient with a value range of 0.1-1.0.

[0041] The particle size of magnetic flocs is detected by analyzing the light intensity signal parameters at scattering angles of 135° and 30°. The light intensity at a scattering angle of 135° is more sensitive to small particles, while the light intensity at a scattering angle of 30° is more sensitive to large particles. Therefore, the ratio of the two can reflect the size distribution characteristics of the particles—the larger the ratio, the higher the proportion of large particles in the flocs, and vice versa.

[0042] The calibration coefficient k is used to correct for the influence of experimental conditions on the light intensity signal, ensuring the accuracy of measurements under different detection systems. The value of k is usually in the range of 0.1-1.0, and the specific value needs to be determined through experiments with standard particle solutions. For example, standard particles of known particle size can be used for calibration, and k can be adjusted according to the correspondence between the measured light intensity ratio and the actual particle size to adapt it to the needs of a specific detection environment.

[0043] The diameter state parameter of the magnetic floc is determined based on the average diameter parameter and the diameter deviation parameter. The average diameter parameter is the average value of the magnetic floc diameter, and the diameter deviation parameter is the standard deviation of the magnetic floc diameter. The magnetic floc diameter state parameter D has a relationship. D a For diameter average parameters, This is the diameter deviation parameter.

[0044] The determination of the diameter state parameters of magnetic flocs depends on a comprehensive analysis of the floc particle size distribution. The average diameter parameter, which is the arithmetic mean of the diameters of all flocs, reflects the overall particle size level of the floc population and is the core indicator for measuring the degree of floc growth. A higher average means that the flocs are generally larger, which is conducive to removal by gravity sedimentation or membrane filtration. However, if the average is too high, it may lead to an overly loose floc structure, which may increase the risk of membrane fouling.

[0045] The diameter deviation parameter, which serves as the standard deviation of the floc diameter, characterizes the dispersion of the particle size distribution. A smaller deviation indicates that the floc particle size is uniform, making it easier to form a dense and uniform filter cake layer during filtration, which helps maintain a stable membrane flux. A larger deviation indicates that the floc particle size varies significantly, and there may be some flocs that are too small or too large. Flocs that are too small can easily penetrate the filter cake layer and aggravate membrane fouling, while flocs that are too large may cause local pore blockage in the filter cake layer, affecting the treatment efficiency.

[0046] The floc quality index is determined based on the synergistic effect of these two parameters. It needs to reflect both the influence of average particle size on the overall performance of the flocs and the uniformity of particle size distribution. The floc quality index F exhibits the following relationship: .

[0047] This directly reflects the product relationship between the density of the floc structure and the particle size distribution characteristics, emphasizing that both must reach a high level simultaneously to achieve high-quality flocs. and These represent the degree of defects in structure and particle size, respectively. When either parameter is poor, the product of the defect terms increases, the denominator decreases, and the overall floc quality index decreases.

[0048] When any parameter is below the threshold, the rate of decrease in the denominator exceeds the rate of increase in the numerator, resulting in a sharp drop in the floc mass index.

[0049] There is a relationship between the transmembrane pressure difference T and the transmembrane pressure difference T. ,in For the inlet side pressure, This represents the pressure on the outlet side. The transmembrane pressure difference is the direct driving force for fluid to pass through the membrane. The greater the pressure difference, the stronger the fluid's ability to overcome membrane resistance, and theoretically, more fluid can be pushed through the membrane.

[0050] There is a relationship between membrane flux J and Where Q is the effluent flow rate per unit time and A is the membrane area. Membrane flux is a core indicator for measuring membrane separation efficiency, directly reflecting the treatment capacity of the membrane system. A high membrane flux value indicates excellent membrane performance, but this requires reasonable transmembrane pressure differential and fouling control.

[0051] The membrane state parameter M has a relationship ,in The viscosity of the inlet fluid is denoted as , where This represents the inherent resistance of the membrane. This formula is derived from Darcy's formula. The membrane state parameter represents the resistance of the fouling layer on the membrane surface to fluid flow and is a direct quantitative indicator of membrane fouling. A larger membrane state parameter indicates more severe fouling. The impact of fouling on the system is amplified by the ratio of transmembrane pressure difference to membrane flux, and then the membrane's inherent resistance is subtracted to finally obtain the resistance contributed solely by fouling.

[0052] Both the floc quality threshold and the membrane state threshold are preset values, determined based on historical data.

[0053] There is a minimum standard value for the floc quality threshold. When the floc quality index is higher than the floc quality threshold, the floc quality is considered to meet the standard; otherwise, the floc quality is considered to be substandard. There is a maximum standard value for the membrane state threshold. When the membrane state parameter is lower than the membrane state threshold, the membrane state is considered to meet the standard; otherwise, the membrane state is considered to be substandard.

[0054] The floc quality threshold is a standard for judging whether the flocs are dense and of appropriate size. By setting a preset qualified value, it is confirmed that the flocs are both strong and of appropriate size. The membrane state threshold is a standard for judging whether the membrane fouling is serious. By setting a preset upper limit of fouling resistance, it is confirmed whether the membrane is severely clogged and affecting the filtration efficiency.

[0055] The quality adjustment signals are the coagulant dosage control signal and the magnetic powder dosage increase signal, while the membrane state adjustment signals are the membrane surface cleaning signal and the membrane flux reduction signal.

[0056] The preset floc quality threshold and membrane state threshold are determined based on past data, which can fit the typical characteristics of actual operating scenarios, making the monitoring standards more in line with process requirements, avoiding misjudgments or omissions caused by unreasonable threshold settings, thereby improving the reliability and adaptability of the monitoring system and providing a more accurate basis for subsequent adjustments.

[0057] The quality adjustment signal can optimize the floc formation process by directly controlling the dosage of coagulant and magnetic powder. Increasing the amount of coagulant can enhance the floc coagulation effect, while adding magnetic powder can help enhance the magnetic properties and structural stability of the flocs, reduce the penetration of pollutants caused by floc breakage or excessively small particle size, and ensure stable effluent water quality.

[0058] The membrane condition adjustment signal can promptly remove the reversible fouling layer on the membrane surface by initiating membrane surface cleaning and reducing membrane flux, thus preventing the accumulation of fouling into irreversible damage. It can also alleviate the working pressure on the membrane by adjusting operating parameters, thereby extending the effective service life of the membrane module from an operational perspective and reducing the cost of frequent replacements due to membrane damage.

[0059] By combining the scientific nature of preset thresholds with the targeted nature of adjustment signals, this method achieves closed-loop control of the entire process from floc formation to membrane filtration. This enables the treatment system to respond quickly based on real-time conditions, avoiding water quality fluctuations caused by monitoring lags and reducing the risk of increased membrane fouling, ultimately improving the stability and efficiency of the overall treatment process.

[0060] When the quality of flocs is substandard, a coagulant dosage control signal, a magnetic powder dosage control signal, and a membrane surface cleaning signal are generated. The coagulant dosage control signal is used to increase the amount of coagulant added.

[0061] After optimization, monitoring continues. If the floc quality and membrane condition still do not meet the standards, a coagulant dosage control signal and a membrane flux reduction signal are generated. The coagulant dosage control signal is used to reduce the coagulant dosage.

[0062] When the quality of flocs does not meet the standards, the system simultaneously generates signals for increasing the dosage of coagulant, adjusting the dosage of magnetic powder, and cleaning the membrane surface. This allows for simultaneous intervention from both the source of floc formation and the control of membrane fouling. It improves the floc structure and particle size by strengthening coagulation and supplementing with magnetic powder, and reduces the accumulation of pollutants by cleaning the membrane surface in a timely manner. This avoids the limitations of a single adjustment method and achieves rapid response and synergistic optimization in problem handling.

[0063] If the floc and membrane conditions still do not meet the standards after optimization, the system switches to reducing the amount of coagulant added and lowering the membrane flux. This avoids the problems of excessive floc density or aggravated membrane fouling that may be caused by excessive coagulant. By reducing the amount of coagulant, the floc formation process is balanced, and the membrane flux is reduced to alleviate the membrane working pressure and prevent membrane damage from being accelerated due to continuous high load operation. This demonstrates the system's ability to adapt to the system's operating conditions with fine precision.

[0064] The closed-loop adjustment mechanism, from floc quality to membrane condition, ensures that problems can be quickly improved through intensive measures in the early stages, and that conservative adjustments can be made to protect the equipment when standards are not met. This improves the stability and fault tolerance of the system operation and reduces secondary problems caused by improper adjustments.

[0065] When the floc condition meets the standard but the membrane condition does not, a membrane surface cleaning signal and a membrane flux reduction signal are generated. When both the floc condition and the membrane condition meet the standard, no quality adjustment signal and membrane condition adjustment signal are generated.

[0066] When the floc condition meets the standard but the membrane condition does not, the system only generates a membrane surface cleaning signal and a membrane flux reduction signal. This targeted adjustment avoids excessive intervention in coagulation and magnetic powder addition even when the floc quality has met the standard. This reduces reagent waste and directly solves the membrane fouling problem through precise membrane cleaning and flux control, ensuring that resource input matches the problem and improving adjustment efficiency.

[0067] When both the floc and membrane conditions meet the standards, the system does not generate any adjustment signals, thus avoiding system fluctuations that may be caused by frequent adjustments. This reduces unnecessary operational wear and tear on the equipment, as well as energy consumption, and maintains the continuity and economy of the processing flow.

[0068] Feedforward control predicts membrane fouling risk based on floc quality index and optimizes floc formation process by adjusting the dosage of coagulant and magnetic powder, reducing the migration of pollutants to the membrane system from the source. Feedback control corrects the control strategy in real time based on membrane state parameters. When membrane fouling exceeds the threshold, membrane surface cleaning and flux adjustment are initiated simultaneously to avoid irreversible damage caused by fouling accumulation.

[0069] To prevent membrane operating parameters from being adjusted lagging due to over-reliance on floc optimization, and to avoid the risk of focusing only on membrane condition while ignoring floc performance deterioration, the floc condition and membrane condition are linked to achieve stable monitoring results.

[0070] By using online polarization depolarization ratio detection and multi-angle scattered light intensity analysis, the simultaneous quantification of floc structure order and particle size distribution can be achieved, which can accurately distinguish floc state and avoid the timeliness deviation of offline detection. Combined with online monitoring of transmembrane pressure difference and membrane flux, the degree of membrane fouling can be reflected in real time. By judging the type of fouling through the correlation change of TMP and flux, a basis for targeted adjustment is provided, which improves the accuracy and timeliness of real-time monitoring.

[0071] An online monitoring system for magnetic floc state and membrane fouling in magnetic coagulation-ultrafiltration membrane wastewater treatment includes: A polarized light transmitting and receiving unit is used for transmitting and receiving polarized light signals; such as... Figure 2 As shown, the polarized light transmitting and receiving unit includes a polarized light transmitting unit, a parallel receiving unit, and a vertical receiving unit. The polarized light transmitting unit uses a semiconductor laser as the polarization source, and a polarizer is used to adjust the polarization direction of the emitted light. The parallel receiving unit is used to receive polarized light in the parallel direction, and the vertical receiving unit is used to receive polarized light in the vertical direction. The parallel receiving unit and the vertical receiving unit are respectively composed of a photodetector and an analyzer.

[0072] A scattered light transmitting and receiving unit is used for transmitting and receiving light intensity signals at 135° and 30°, respectively, of unpolarized light; such as... Figure 3 As shown, the scattered light transmitting and receiving unit includes a scattered light transmitting unit, a 30° scattered light receiving unit, and a 135° scattered light receiving unit. The scattered light transmitting unit uses an LED as its light source, and the emitted wavelength is consistent with the polarized light. The 30° and 135° scattered light receiving units are used to detect scattered light at 30° and 135° angles, respectively. The 30° and 135° scattered light receiving units are composed of an optical fiber bundle or lens group, a narrowband filter, and a photodetector array, respectively.

[0073] The depolarization ratio calculation unit is used to receive polarized light signals and calculate the depolarization ratio; it is a microprocessor.

[0074] The particle size calculation unit is used to receive light intensity signals and calculate the diameter of the magnetic flocculent; it is a microprocessor.

[0075] The floc mass calculation unit is used to calculate the floc mass quality index; it is a microprocessor.

[0076] The membrane state detection unit is used to acquire the transmembrane pressure difference and flux parameters of the ultrafiltration membrane; it includes a pressure sensor and a flow meter.

[0077] The membrane state calculation unit is used to calculate membrane state parameters; it is a microprocessor.

[0078] The floc quality comparison unit is used to compare the floc quality index with the quality threshold; it is a microprocessor with a logic judgment module.

[0079] The membrane state comparison unit is used to compare membrane state parameters with membrane state thresholds; it is a microprocessor with a logic judgment module.

[0080] The discrimination unit is used to determine the quality of flocs and the state of the membrane; it is a microprocessor with a logic judgment module.

[0081] The signal generation unit is used to generate quality adjustment signals and membrane state adjustment signals; it is a digital output module.

[0082] The actuator is used to execute quality adjustment signals and membrane state adjustment signals; it is a component of electric metering pumps, backwash pumps, etc.

[0083] The transmission unit is used for data transmission. It is a Wi-Fi / LoRa module.

[0084] Exemplary electronic devices To achieve the above objectives, the third technical solution adopted by the present invention is: an electronic device, comprising: Processor; a processor may be a central processing unit (CPU) or other form of processing unit with data processing capabilities and / or instruction execution capabilities.

[0085] The memory stores computer program instructions, which, when executed by the processor, cause the processor to perform an online monitoring method for the state of magnetic flocs and membrane fouling in magnetic coagulation-ultrafiltration membrane wastewater treatment.

[0086] The memory may include one or more computer program products, which may include various forms of computer-readable storage media, such as volatile memory and / or non-volatile memory. The volatile memory may include, for example, random access memory and / or cache memory. The non-volatile memory may include, for example, read-only memory, hard disk, flash memory, etc. One or more computer program instructions may be stored on the computer-readable storage medium, and a processor may execute the program instructions to implement the online monitoring method for magnetic floc state and membrane fouling in magnetic coagulation-ultrafiltration membrane wastewater treatment described in the various embodiments of this application above, and / or other desired functions.

[0087] To achieve the above objectives, the fourth technical solution adopted by the present invention is: a computer-readable storage medium storing computer program instructions thereon, wherein the computer program instructions, when run by a processor, cause the processor to execute a method for online monitoring of magnetic floc state and membrane fouling in magnetic coagulation-ultrafiltration membrane wastewater treatment.

[0088] Computer-readable storage media can take the form of any combination of one or more readable media. A readable medium can be a readable signal medium or a readable storage medium. A readable storage medium can be, for example, an electrical, magnetic, optical, electromagnetic, infrared, or semiconductor system, apparatus, or device, or any combination thereof. More specific examples of readable storage media include: electrical connections having one or more wires, portable disks, hard disks, random access memory (RAM), read-only memory (ROM), erasable programmable read-only memory (EPROM or flash memory), optical fiber, portable compact disk read-only memory (CD-ROM), optical storage devices, magnetic storage devices, or any suitable combination thereof.

[0089] Based on the preferred embodiments of the present invention described above, those skilled in the art can make various changes and modifications without departing from the inventive concept. The technical scope of this invention is not limited to the contents of the specification, but must be determined according to the scope of the claims.

Claims

1. A method for online monitoring of magnetic floc state and membrane fouling in magnetic coagulation-ultrafiltration membrane wastewater treatment, characterized in that, include: S1: Obtain the polarization intensity parameters of the magnetic flocculant, calculate the depolarization ratio, and obtain the polarization structure state parameters of the magnetic flocculant; S2: Obtain the light intensity signal parameters at 135° and 30° scattering angles of the magnetic floc, calculate the diameter of the magnetic floc, and obtain the magnetic floc diameter state parameters; use the magnetic floc polarization structure state parameters and the magnetic floc diameter state parameters to calculate the floc mass index; S3: Obtain the transmembrane pressure difference and flux parameters of the ultrafiltration membrane, calculate the membrane state parameters, and obtain the membrane state parameters; S4: Compare the floc mass index with the mass threshold and the membrane state parameter with the membrane state threshold respectively, and generate the mass adjustment signal and the membrane state adjustment signal respectively; S5: Optimize the treated wastewater using the quality adjustment signal and the membrane state adjustment signal.

2. The method for online monitoring of magnetic floc state and membrane fouling in magnetic coagulation-ultrafiltration membrane wastewater treatment according to claim 1, characterized in that: The polarization intensity parameters of the magnetic floc include vertical detection parameters and parallel detection parameters. The depolarization ratio is the ratio of the vertical detection parameter to the parallel detection parameter. The polarization structure state parameter P of the magnetic floc exists in the following relationship: Where I1 is the vertical detection parameter and I2 is the parallel detection parameter.

3. The method for online monitoring of magnetic floc state and membrane fouling in magnetic coagulation-ultrafiltration membrane wastewater treatment according to claim 2, characterized in that: The relationship between the light intensity signal parameters of the magnetic floc at 135° and 30° scattering angles and the particle size of the magnetic floc is d. Where I3 is the light intensity parameter at a 135° scattering angle, I4 is the light intensity parameter at a 30° scattering angle, and k is the calibration coefficient with a value range of 0.1-1.

0.

4. The method for online monitoring of magnetic floc state and membrane fouling in magnetic coagulation-ultrafiltration membrane wastewater treatment according to claim 3, characterized in that: The diameter state parameter of the magnetic floc is determined based on the average diameter parameter and the diameter deviation parameter. The average diameter parameter is the average value of the magnetic floc diameter, and the diameter deviation parameter is the standard deviation of the magnetic floc diameter. The magnetic floc diameter state parameter D has a relationship. D a For diameter average parameters, This is the diameter deviation parameter.

5. The method for online monitoring of magnetic floc state and membrane fouling in magnetic coagulation-ultrafiltration membrane wastewater treatment according to claim 4, characterized in that: The floc quality index F has the following relationship: .

6. The method for online monitoring of magnetic floc state and membrane fouling in magnetic coagulation-ultrafiltration membrane wastewater treatment according to claim 1, characterized in that: There is a relationship between the transmembrane pressure difference T and the transmembrane pressure difference T. ,in For the inlet side pressure, The pressure on the outlet side; the membrane state parameter M has a relationship. ,in The viscosity of the inlet fluid is denoted as , where This represents the inherent resistance of the membrane.

7. The method for online monitoring of magnetic floc state and membrane fouling in magnetic coagulation-ultrafiltration membrane wastewater treatment according to claim 1, characterized in that: Both the floc mass threshold and the membrane state threshold are preset values, determined based on past data. The mass adjustment signals are the coagulant dosage control signal and the magnetic powder dosage increase signal, while the membrane state adjustment signals are the membrane surface cleaning signal and the membrane flux reduction signal.

8. The method for online monitoring of magnetic floc state and membrane fouling in magnetic coagulation-ultrafiltration membrane wastewater treatment according to claim 7, characterized in that: When the quality of flocs is substandard, a coagulant dosage control signal, a magnetic powder dosage control signal, and a membrane surface cleaning signal are generated. The coagulant dosage control signal is used to increase the amount of coagulant added. After optimization, monitoring continues. If the floc quality and membrane condition still do not meet the standards, a coagulant dosage control signal and a membrane flux reduction signal are generated. The coagulant dosage control signal is used to reduce the coagulant dosage.

9. The method for online monitoring of magnetic floc state and membrane fouling in magnetic coagulation-ultrafiltration membrane wastewater treatment according to claim 7, characterized in that: When the floc condition meets the standard but the membrane condition does not, a membrane surface cleaning signal and a membrane flux reduction signal are generated; when both the floc condition and the membrane condition meet the standard, no quality adjustment signal and membrane condition adjustment signal are generated.

10. An online monitoring system for the state of magnetic flocs and membrane fouling in magnetic coagulation-ultrafiltration membrane wastewater treatment, based on the online monitoring method for the state of magnetic flocs and membrane fouling in magnetic coagulation-ultrafiltration membrane wastewater treatment according to any one of claims 1-9, characterized in that, include: A polarized light transmitting and receiving unit is used for transmitting and receiving polarized light signals. The scattered light transmitting and receiving unit is used for transmitting and receiving light intensity signals at 135° and 30° respectively, for the transmission of unpolarized light; Depolarization ratio calculation unit, used to receive polarized light signals and calculate depolarization ratio; The particle size calculation unit is used to receive light intensity signals and calculate the diameter of the magnetic flocs; The floc mass calculation unit is used to calculate the floc mass index. The membrane state detection unit is used to acquire the transmembrane pressure difference and flux parameters of the ultrafiltration membrane; Membrane state calculation unit, used to calculate membrane state parameters; The floc quality comparison unit is used to compare the floc quality index with the quality threshold. The membrane state comparison unit is used to compare membrane state parameters with membrane state thresholds. The discrimination unit is used to determine the quality of flocs and the condition of the membrane. The signal generation unit is used to generate quality adjustment signals and membrane state adjustment signals; The execution unit is used to execute quality adjustment signals and membrane state adjustment signals; A transmission unit is used to transmit data.

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