Method for determining service life of filter membrane backwash
By measuring the number of backwashes of the filter membrane under different backwash pressures and establishing a mathematical model, combined with pilot-scale environmental testing, the problem of the inability to assess the long-term service life of membrane products in existing technologies has been solved, enabling accurate prediction of membrane product lifespan and providing guidance for research and development.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- WUXI ENERGY NEW MATERIALS TECH CO LTD
- Filing Date
- 2022-08-17
- Publication Date
- 2026-05-29
AI Technical Summary
Existing membrane product life testing methods cannot effectively assess whether they can achieve a service life of more than 5 years, and existing testing methods are mainly limited to short-term laboratory testing, which cannot meet the needs of actual use.
By backwashing the filter membrane under different backwashing pressures, the number of backwashes was measured, and a mathematical model of backwashing pressure and number of backwashes was established. Combined with pilot-scale environmental testing, the actual number of backwashes for the filter membrane was predicted, and the lifespan was determined using functional relationships and deviation rates.
It enables the assessment of the filtration membrane's performance over 5 to 10 years in short-term testing, provides predictive guidance for newly developed membrane products, and improves the accuracy and reliability of membrane product life assessment.
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Figure CN115329576B_ABST
Abstract
Description
Technical Field
[0001] This application relates to the field of membrane products, and more specifically, to a method for determining the service life of a filter membrane after backwashing. Background Technology
[0002] Current wastewater treatment processes mainly consist of two stages: reaction and separation. The reaction stage involves using physicochemical and biological methods to convert dissolved pollutants in water into insoluble forms. Separation then removes these pollutants from the water, resulting in clarified effluent. Membrane technology, thanks to its superior separation capabilities, plays a crucial role in wastewater treatment.
[0003] In wastewater treatment, membranes primarily separate pollutants from permeate through suction. Therefore, pollutants accumulate on the membrane surface during use, requiring cleaning to remove them. This cleaning process often involves injecting clean water or prepared chemical agents into the membrane in the opposite direction to the permeate flow, achieving a cleaning effect; this process is called backwashing. Consequently, the tolerance of membrane products to backwash pressure and the number of backwash cycles is a crucial factor affecting their lifespan and is also an important standard for evaluating membrane product quality and technological level.
[0004] The market expectation for the lifespan of membrane products has increased from 2 to 3 years to 5 to 10 years. While existing membrane product lifespan testing methods include pressure testing, these tests are currently limited to short-term laboratory testing. For materials and product development, it is clearly impossible to directly assess whether a product can achieve a lifespan of more than 5 years using existing methods. Summary of the Invention
[0005] The purpose of this application is to provide a method for determining the service life of a filter membrane after backwashing.
[0006] In a first aspect, this application provides a method for determining the service life of a filter membrane after backwashing, including:
[0007] The filter membrane was backwashed under n different backwash pressures, and the n values corresponded one-to-one to the first number of backwashes that the filter membrane could withstand under the n different backwash pressures.
[0008] A mathematical model was fitted for n different backwash pressures and n first backwash cycles, and a functional relationship between backwash pressure and the number of backwash cycles that can be tolerated was established.
[0009] The filter membrane was backwashed n times under n different backwash pressures in a pilot-scale environment. The number of second backwashes that the filter membrane could withstand under the n different backwash pressures was measured. The deviation was obtained by comparing each first backwash number with each second backwash number.
[0010] The service life of filter membrane backwashing is determined by using functional relationships and deviations;
[0011] Where n is greater than or equal to 3.
[0012] The method for determining the backwash lifespan of a filter membrane provided in this application can, on the one hand, predict the actual number of backwashes at any backwash pressure value, thereby predicting the lifespan. On the other hand, when dealing with newly developed filter membranes, tests can be conducted in the laboratory at any backwash pressure to obtain the corresponding number of backwashes; by comparing the number of backwashes with that of a standard product, it can be predicted whether the developed product meets actual usage requirements, providing further guidance for research and development. The method for determining the backwash lifespan of a filter membrane provided in this application can evaluate the product's usage status after 5 to 10 years of use through short-term testing of 1 to 3 months.
[0013] In other embodiments of this application, n is equal to 10 to 12.
[0014] In other embodiments of this application, the steps described above for fitting a mathematical model to n different backwash pressures and n first backwash cycles, and establishing a functional relationship between backwash pressure and the number of backwash cycles tolerated, include:
[0015] A mathematical relationship model is selected based on n different backwash pressures and n first backwash cycles. The mathematical relationship model is then fitted to the n different backwash pressures and n first backwash cycles, and correction values are determined.
[0016] In other embodiments of this application, the above-mentioned functional relationship is Y=f(X,R,N);
[0017] In the formula, X is the backwash pressure in kPa, X is the change value; Y is the number of backwashes; R and N are correction values.
[0018] In other embodiments of this application, the functional relationship is Y = -366.8X + 19169, R 2 = 0.9775, N is 19169.
[0019] In other embodiments of this application, the step of comparing each first backwash count and each second backwash count to obtain the deviation includes:
[0020] Compare each first backwash count with each second backwash count to obtain n deviation values, and then calculate the average deviation rate of the n deviation values.
[0021] In other embodiments of this application, the average deviation rate is 3.15.
[0022] In other embodiments of this application, the step of determining the backwashing lifespan of the filter membrane using functional relationships and deviations includes:
[0023] The number of backwashes is calculated based on the functional relationship. Then, the average deviation rate is added to the number of backwashes to obtain the actual backwash life of the filter membrane.
[0024] In other embodiments of this application, the filter membrane includes any one of a flat sheet membrane, a hollow fiber membrane, or a flexible membrane.
[0025] In other embodiments of this application, the step of backwashing the filter membrane under n different backwashing pressures includes:
[0026] The steps of backwashing the filter membrane under n different backwashing pressures include:
[0027] Backwashing was performed using a pressure testing device;
[0028] The pressurization test device includes: a water storage tank, a backwash circuit, and a suction circuit;
[0029] Backwashing includes: immersing the filter membrane in a water storage tank; the backwashing circuit draws water from the water storage tank and discharges water to the filter membrane; the suction circuit draws water from the filter membrane and discharges water to the water storage tank; the backwashing circuit and the suction circuit operate alternately; n different backwashing pressures are set for backwashing; and / or
[0030] The steps of backwashing the filter membrane in a pilot-scale environment under n different backwashing pressures include:
[0031] Backwashing was performed using a pilot-scale device;
[0032] The pilot plant includes: a backwash pump, a product water pump, a backwash valve, a product water valve, a water tank, and pipelines; the backwash pump, product water pump, backwash valve, product water valve, and water tank are connected by pipelines; the filter membrane is placed in the water tank and operates for backwashing or product water production;
[0033] During backwashing, the backwash pump starts, the backwash valve opens, the product water valve closes, and the product water pump stops to perform backwashing. Attached Figure Description
[0034] To more clearly illustrate the technical solutions of the embodiments of this application, the accompanying drawings used in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of this application and should not be regarded as a limitation of the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.
[0035] Figure 1 A structural diagram of the pressure testing device provided in the embodiments of this application;
[0036] Figure 2 A structural diagram of the pilot-scale device provided for an embodiment of this application;
[0037] Figure 3 A mathematical model was fitted to the number of backwash cycles that the embodiments of this application can withstand.
[0038] Icons: 10-Filter membrane; 100-Pressure testing device; 110-Water storage tank; 120-Backwash circuit; 130-Suction circuit; 121-Pressure gauge; 131-Vacuum gauge; 122-First valve; 132-Second valve; 200-Pilot plant; 210-Backwash pump; 220-Product water pump; 230-Backwash valve; 240-Product water valve; 250-Flow meter; 260-Electrical control box; 270-Water tank; 280-Pipeline. Detailed Implementation
[0039] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the technical solutions in the embodiments of this application will be clearly and completely described below. Obviously, the described embodiments are some embodiments of this application, but not all embodiments.
[0040] Therefore, the following detailed description of the embodiments of this application is not intended to limit the scope of the claimed application, but merely to illustrate selected embodiments of the application. All other embodiments obtained by those skilled in the art based on the embodiments of this application without inventive effort are within the scope of protection of this application.
[0041] This application provides a method for determining the service life of a filter membrane after backwashing, including the following steps:
[0042] Step S1: Backwash the filter membrane under n different backwash pressures, and measure the first number of backwashes that the filter membrane can withstand under the n different backwash pressures.
[0043] Furthermore, in some embodiments of this application, the above-mentioned n is greater than or equal to 3.
[0044] Furthermore, in some embodiments of this application, n is equal to 10 to 12.
[0045] For example, the filter membrane was backwashed at 3, 4, 5, 6, 7, 8, 9, 10, 11 or 12 different backwash pressures, and the first number of backwashes that the filter membrane could withstand at 3, 4, 5, 6, 7, 8, 9, 10, 11 or 12 different backwash pressures was measured one by one.
[0046] In some embodiments of this application, the backwashing service life of the filter membrane can be determined by testing the mechanical strength of the filter membrane.
[0047] Furthermore, in some embodiments of this application, the step of backwashing the filter membrane under n different backwashing pressures includes:
[0048] Reference Figure 1 Backwashing was performed using a pressure testing device 100.
[0049] The pressure testing device 100 includes: a water storage tank 110, a backwashing circuit 120 from which water enters the water storage tank and exits the filter membrane, and a suction circuit 130 from which water enters the filter membrane and exits the water storage tank; the backwashing circuit 120 and the suction circuit 130 operate alternately.
[0050] Backwashing includes: immersing the filter membrane in the water storage tank 110 of the membrane element; the backwashing circuit 120 receiving water from the water storage tank 110 and discharging water from the filter membrane 10; and the suction circuit 130 receiving water from the filter membrane and discharging water from the water storage tank 110. The backwashing circuit 120 and the suction circuit 130 operate alternately. N different backwashing pressures are set for backwashing.
[0051] By controlling the time, the suction circuit 130 and the backwash circuit 120 are cyclically activated, causing the test filter membrane 10 to continuously switch between suction and backwash. The backwash pressure and suction pressure are displayed by the pressure gauge 121 and the vacuum gauge 131, and the magnitude of the backwash pressure and suction pressure are controlled by the first valve 122 and the second valve 132. Ultimately, the device can achieve backwashing at the set backwash pressure. The backwashing duration can be set. After the backwashing is completed, suction can be started after a set interval and performed at the set suction pressure. The duration can also be set. After the suction is completed, backwashing is started again after a set interval, realizing the cyclic operation of backwashing and suction.
[0052] In other optional embodiments of this application, other devices may be used to backwash the filter membrane 10.
[0053] For example, the pressure testing device 100 described above is only provided with a backwash circuit 120, and the backwash pressure needs to be controlled at the aforementioned n different backwash pressures during backwashing.
[0054] Furthermore, in some embodiments of this application, the filter membrane includes any one of a flat sheet membrane, a hollow fiber membrane, or a flexible membrane.
[0055] In some embodiments of this application, the filter membrane is backwashed at 12 different backwash pressures, and 12 first backwash cycles are measured. Exemplarily:
[0056] Using the pressurization test device 100, at X a1The withstand capability of filter membrane a is tested under a backwashing pressure of kPa. Assume that it can withstand a certain number of backwashing cycles, Y. a1 .
[0057] Using the pressurization test device 100, at X a2 The withstand capability of filter membrane a is tested under a backwash pressure of kPa. Assume that it can withstand Y backwash cycles. a2 .
[0058] Using the pressurization test device 100, at X a3 The withstand capability of filter membrane a is tested under a backwash pressure of kPa. Assume that it can withstand Y backwash cycles. a3 .
[0059] X was measured in this way a12 The number of backwashes under a backwash pressure of kPa is Y. a12 .
[0060] Step S2: Fit a mathematical model to the n backwash pressures and n tolerance backwash times obtained from the test in Step S1, and establish a functional relationship between the backwash pressure and the tolerance backwash times.
[0061] The steps for fitting a mathematical model to the n different backwash pressures and n corresponding numbers of first backwash cycles that the filter membrane can withstand under the n different backwash pressures obtained in step S1 include:
[0062] Based on the n different backwash pressures and n first backwash counts that the filter membrane can withstand under the n different backwash pressures obtained in step S1, a mathematical relationship model is selected. The mathematical relationship model is then fitted to the n different backwash pressures and the n first backwash counts, and the correction values are determined.
[0063] In some embodiments of this application, the selected mathematical relationship model is a linear relationship. The n different backwash pressures obtained from testing and the n corresponding numbers of first backwash cycles that the filter membrane can withstand under these n different backwash pressures are fitted using a linear relationship, and the confirmed correction value is R. 2 .
[0064] Furthermore, in some embodiments of this application, the confirmed functional relationship is the functional relationship Y=f(X,R,N);
[0065] In the formula, X is the backwash pressure in kPa, and X is the change value; Y is the number of backwashes; R and N are correction values and are constants.
[0066] In some embodiments of this application, the functional relationship is Y = -366.8X + 19169, R 2 = 0.9775, N is 19169.
[0067] Step S3: Backwash the filter membrane in a pilot-scale environment under n different backwash pressures, and measure the number of second backwashes that the filter membrane can withstand under the n different backwash pressures.
[0068] Furthermore, in some embodiments of this application, the above-mentioned n is greater than or equal to 3.
[0069] Furthermore, in some embodiments of this application, n is equal to 10 to 12.
[0070] For example, the filter membrane is backwashed at 3, 4, 5, 6, 7, 8, 9, 10, 11 or 12 different backwash pressures, and the number of second backwashes of 3, 4, 5, 6, 7, 8, 9, 10, 11 or 12 are measured one by one.
[0071] The pilot-scale environment is similar to the actual usage environment of the product in reality, and the results of the pilot-scale test are generally used to estimate the actual service life of the product.
[0072] In some embodiments of this application, the filter membrane is backwashed in a pilot-scale environment under n different backwashing pressures, and n second backwashing cycles corresponding one-to-one with the filter membrane's ability to withstand under the n different backwashing pressures are measured, including:
[0073] A pilot-scale apparatus was used to backwash the filter membrane n times under n different backwash pressures, and the n values corresponded one-to-one with the second backwash number that the filter membrane could withstand under the n different backwash pressures.
[0074] Furthermore, such as Figure 2 As shown, the pilot plant 200 includes: a backwash pump 210, a product water pump 220, a backwash valve 230, a product water valve 240, a flow meter 250, an electrical control box 260, a water tank 270, and pipelines 280. The backwash pump 210, product water pump 220, backwash valve 230, product water valve 240, flow meter 250, electrical control box 260, and water tank 270 are connected via pipelines 280. A flow meter 250 is installed on pipelines 280. The backwash pump 210 and product water pump 220 are connected to the electrical control box 260 for controlling the pumps' on / off states. The filter membrane 10 is placed in the water tank 270 for backwashing or product water operation.
[0075] During backwashing, the backwash pump 210 is started, the backwash valve 230 is opened, the product water valve 240 is closed, and the product water pump 220 is stopped to perform backwashing and achieve the backwashing effect.
[0076] The pilot plant 200 has a similar structure to the laboratory plant, but its operation mode is different. The laboratory plant operates with short intervals and high frequency, while the pilot plant 200 operates with long intervals and low frequency. The entire system of the pilot plant 200 is almost the same as the actual system during actual operation, and the operation mode is also the same. Therefore, the operation results are closer to the actual data.
[0077] In some embodiments of this application, the filter membrane is backwashed in a pilot-scale environment at 12 different backwash pressures, and 12 second backwash cycles are measured. Exemplarily:
[0078] Through a pilot-scale device, in X a1 The withstand capability of filter membrane a is tested under a backwash pressure of ′kPa, assuming that it can withstand Y backwash cycles. a1 ′.
[0079] Through a pilot-scale device, in X a2 The withstand capability of filter membrane a is tested under a backwash pressure of ′kPa, assuming that it can withstand Y backwash cycles. a2 ′.
[0080] Through a pilot-scale device, in X a3 The withstand capability of filter membrane a is tested under a backwash pressure of ′kPa, assuming that it can withstand Y backwash cycles. a3 ′.
[0081] X was measured in this way a12 The number of backwashes under a backwash pressure of 'kPa is Y. a12 ′.
[0082] Step S4: Compare each first backwash count and each second backwash count obtained in steps S2 and S3 to obtain the deviation.
[0083] The steps to compare each first backwash count with each second backwash count to obtain the deviation include:
[0084] Compare each first backwash count with each second backwash count to obtain n deviation values, and then calculate the average deviation rate of the n deviation values.
[0085] For example, in some embodiments of this application, the first backwashing number and the second backwashing number are both 12, so the deviation rate is the average deviation of the 12 first backwashing numbers and the second backwashing number.
[0086] In some embodiments of this application, the average deviation rate is 3.15.
[0087] Step S5: Use functional relationships and deviation rates to determine the service life of the filter membrane during backwashing.
[0088] In some embodiments of this application, the step of determining the backwashing lifespan of the filter membrane using functional relationships and deviation rates includes:
[0089] The number of backwashes is calculated based on the functional relationship. Then, the amount corresponding to the average deviation rate is added to the number of backwashes to obtain the actual backwash life of the filter membrane.
[0090] The features and performance of this application will be further described in detail below with reference to embodiments:
[0091] Example 1
[0092] A method for determining the service life of a filter membrane by backwashing is provided, which is carried out according to the following steps: The selected filter membrane is a flat sheet membrane.
[0093] Using the pressurization test device 100, at X a1 The backwashing pressure of the flat sheet membrane a was tested at kPa, assuming that it can withstand Y backwashing cycles. a1 .
[0094] Using the pressurization test device 100, at X a2 The backwashing pressure of the flat sheet membrane a was tested at kPa, assuming that it can withstand Y backwashing cycles. a2 .
[0095] Using the pressurization test device 100, at X a3 The backwashing pressure of the flat sheet membrane a was tested at kPa, assuming that it can withstand Y backwashing cycles. a3 .
[0096] X was measured in this way a12 The number of backwashes under a backwash pressure of kPa is Y. a12 .
[0097] Through a pilot-scale device, in X a1 The backwashing performance of sheet membrane a was tested under a backwashing pressure of ′kPa, assuming that it can withstand Y backwashing cycles. a1 ′.
[0098] Through a pilot-scale device, in X a2 The backwashing performance of sheet membrane a was tested under a backwashing pressure of ′kPa, assuming that it can withstand Y backwashing cycles. a2 ′.
[0099] Through a pilot-scale device, in X a3 The backwashing performance of sheet membrane a was tested under a backwashing pressure of ′kPa, assuming that it can withstand Y backwashing cycles. a3 ′.
[0100] X was measured in this way a12The number of backwashes under a backwash pressure of 'kPa is Y. a12 ′.
[0101] The deviation rate is obtained by comparing the 12 first backwash counts and 12 second backwash counts obtained above. For example... Figure 3 As shown.
[0102] The service life of the filter membrane after backwashing is determined by using functional relationships and deviation rates.
[0103] The results are shown in Table 1:
[0104] Table 1
[0105]
[0106] Mathematical models were fitted for 12 backwash pressures and 12 withstand backwash cycles, see [link to model]. Figure 3 The functional relationship between pressure and the number of backwash cycles tolerable is established as follows:
[0107] Y=f(X,R,N):Y = -366.8X+ 19169,R 2 = 0.9775;
[0108] Where X represents the corresponding backwash pressure, Y represents the corresponding number of backwashes, and the Y value corresponds to the service life. Next, the deviation rate is calculated through pilot-scale testing, and then the average deviation rate is obtained, as shown in Table 2:
[0109] Table 2
[0110]
[0111] The average deviation rate was 3.15%. By comparing the values from the pilot plant and the stamping test, and combining this with the average deviation, we can conclude that, using the formula Y=f(X,R,N): Y= -366.8X + 19169, R 2 = 0.9775 can be used to calculate the number of backwashes under different backwash pressures. Adding the average deviation rate of 3.15 to this calculation result will give the actual lifespan value, which can be considered as the product's lifespan.
[0112] For example, the lifespan of the filter membrane is tested:
[0113] The lifetime function of the MBR filtration membrane is Y = -366.8X + 19169, R. 2 = 0.9775, N is 19169, the average deviation rate is 3.15. In a slaughterhouse wastewater filtration project in Xianghe, Hebei, the operating environment pressure of the MBR filter membrane is 26 kPa. Based on the life function relationship, the calculated number of backwashing times is 9632.2 times, and the estimated lifespan is about 69 days.
[0114] Meanwhile, a pilot-scale experimental membrane of 120 square meters was used. The pilot-scale device was operated in a cyclic mode of 8 minutes of operation, 1 minute of stop, and 1 minute of backwashing. The backwashing pressure was about 26 kPa. Lifetime prediction verification was carried out. After 71 days of continuous operation, some membrane damage occurred, which matched the predicted value of the lifetime function.
[0115] The method for determining the service life of filter membranes provided in this application can predict the actual number of backwashes at any backwash pressure value, thereby predicting the service life.
[0116] On the other hand, when dealing with newly developed filter membranes, tests can be conducted in the laboratory at any backwash pressure to obtain the corresponding number of backwashes; this backwash pressure value can then be substituted into the function Y=f(X,R,N): Y= -366.8X + 19169, R 2 =0.9775, the number of backwashes for the standard product is obtained. By comparing the number of backwashes for the two products, it is possible to predict whether the product under development meets the actual use requirements and provide further guidance for the research and development.
[0117] For example: The new product underwent backwashing testing using the same equipment and process, and the data obtained is as follows:
[0118]
[0119] The data shows that the new product's test results are better than the theoretical function results, indicating that the new product meets the expected requirements.
[0120] The above description is merely a preferred embodiment of this application and is not intended to limit this application. Various modifications and variations can be made to this application by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application should be included within the protection scope of this application.
Claims
1. A method for determining the service life of a filter membrane after backwashing, characterized in that, include: The filter membrane was backwashed under n different backwash pressures, and the n backwash counts were measured to correspond one-to-one with the first number of backwashes that the filter membrane could withstand under the n different backwash pressures. A mathematical model was fitted to the n different backwash pressures and n first backwash cycles, and a functional relationship between backwash pressure and the number of backwash cycles that can be withstood was established. The filter membrane was backwashed in a pilot-scale environment under n different backwash pressures, and n second backwash counts corresponding to the filter membrane's tolerance under the n different backwash pressures were measured; the deviation was obtained by comparing each first backwash count with each second backwash count. The backwashing lifespan of the filter membrane is determined using the aforementioned functional relationship and the aforementioned deviation. Wherein, n is greater than or equal to 3; the step of determining the filter membrane backwashing service life using the functional relationship and the deviation includes: The number of backwashes is calculated based on the aforementioned functional relationship. Then, the average deviation rate is added to the number of backwashes to obtain the actual backwash lifespan of the filter membrane.
2. The method for determining the service life of a filter membrane after backwashing according to claim 1, characterized in that, The value of n is 10 to 12.
3. The method for determining the service life of a filter membrane after backwashing according to claim 1, characterized in that, The steps of fitting a mathematical model to the n different backwash pressures and the n first backwash cycles, and establishing a functional relationship between backwash pressure and the number of backwash cycles tolerated, include: A mathematical relationship model is selected based on the n different backwash pressures and the n first backwash cycles. The mathematical relationship model is then fitted to the n different backwash pressures and the n first backwash cycles, and a correction value is determined.
4. The method for determining the service life of a filter membrane after backwashing according to claim 3, characterized in that, The functional relationship is Y=f(X,R,N); In the formula, X is the backwash pressure in kPa, and X is the change value; Y is the number of backwashes; R and N are correction values.
5. The method for determining the service life of a filter membrane after backwashing according to claim 4, characterized in that, The functional relationship is Y = -366.8X + 19169, R 2 = 0.9775, N is 19169.
6. The method for determining the service life of a filter membrane after backwashing according to claim 1, characterized in that, The step of comparing each of the first backwash counts and each of the second backwash counts to obtain the deviation includes: Each first backwash count and each second backwash count are compared to obtain n deviation values, and then the average deviation rate of the n deviation values is calculated.
7. The method for determining the service life of a filter membrane after backwashing according to claim 5, characterized in that, The average deviation rate was 3.
15.
8. The method for determining the service life of a filter membrane after backwashing according to any one of claims 1-7, characterized in that, The filter membrane includes any one of flat sheet membrane, hollow fiber membrane, or flexible membrane.
9. The method for determining the service life of a filter membrane after backwashing according to any one of claims 1-7, characterized in that, The step of backwashing the filter membrane under n different backwashing pressures includes: Backwashing was performed using a pressure testing device; The pressurization test device includes: a water storage tank, a backwashing circuit, and a suction circuit; The backwashing includes: immersing the filter membrane in the water storage tank; the backwashing circuit receiving water from the water storage tank and discharging water from the filter membrane; and the suction circuit receiving water from the filter membrane and discharging water from the water storage tank; the backwashing circuit and the suction circuit operating alternately; setting n different backwashing pressures for backwashing; and / or The step of backwashing the filter membrane in a pilot-scale environment under n different backwashing pressures includes: Backwashing was performed using a pilot-scale device; The pilot plant includes: a backwash pump, a product water pump, a backwash valve, a product water valve, a water tank, and pipelines; the backwash pump, the product water pump, the backwash valve, the product water valve, and the water tank are connected by the pipelines; the filter membrane is placed in the water tank and operates for backwashing or product water production; During backwashing, the backwash pump starts, the backwash valve opens, the product water valve closes, and the product water pump stops to perform backwashing.