Preparation method and system of anti-pollution reverse osmosis membrane element

Abstract

The invention relates to the technical field of membranes, and discloses a preparation method and system of an anti-pollution reverse osmosis membrane element, the method comprises the following steps: (1) an anti-pollution agent is pressurized and injected into a plurality of membrane shell units connected in parallel to modify the reverse osmosis membrane element, each membrane shell unit comprises a plurality of membrane shells connected in series, a pressurizing device is arranged between every two adjacent membrane shells, the pressure of each membrane shell is kept between 2 bar and 3 bar through the pressurizing devices, and the number of the reverse osmosis membrane elements in each membrane shell is 1-3; and (2) carrying out circulating flushing on the modified reverse osmosis membrane element until the pH value of discharged water after flushing is greater than 5. By adopting the preparation method of the anti-pollution reverse osmosis membrane element, the anti-pollution reverse osmosis membrane with excellent performance can be stably prepared, the anti-pollution performance effect of the reverse osmosis membrane element is ensured to the maximum extent, and the preparation method is more suitable for industrial application.

Description

Technical Field

[0001] The invention relates to the field of membrane technology, and in particular to a method and system for preparing an anti-pollution reverse osmosis membrane element. Background Art

[0002] The problem of reverse osmosis membrane pollution has always restricted the promotion and development of reverse osmosis technology. Membrane pollution will lead to the decline or loss of membrane performance, thereby reducing the quality of produced water, increasing the energy consumption of produced water, and shortening the service life of the reverse osmosis membrane. In practical applications, pretreatment of feed water, optimization of operating conditions and membrane cleaning are common operations to reduce membrane pollution. However, these operations increase the complexity and cost of the reverse osmosis membrane system to varying degrees. At the same time, chemical substances such as antiscalants, coagulants and chemical cleaning agents used in the pretreatment and cleaning process of the reverse osmosis membrane system have adverse effects on the environment.

[0003] In the prior art, most of the automatic 4-core 8040 industrial membrane modification devices are used to modify the reverse osmosis membrane elements for anti-pollution. The modification device is equipped with multiple 8040*4-core low-pressure membrane shells. In each membrane shell of the device, four membrane elements are connected in series. The anti-pollution agent is sequentially passed through the series-connected membrane elements for anti-pollution modification. However, there is often a problem of uneven modification effect of the membrane elements. Therefore, how to stably prepare anti-pollution reverse osmosis membranes with excellent performance has become a research hotspot in the scientific and industrial communities. Summary of the invention

[0004] The purpose of the present invention is to overcome the problems of uneven modification effect and poor anti-pollution performance of anti-pollution reverse osmosis membrane elements in the prior art, and to provide a method and system for preparing anti-pollution reverse osmosis membrane elements. The method has the characteristics of being able to stably prepare anti-pollution reverse osmosis membranes with excellent performance, and can maximize the anti-pollution performance of reverse osmosis membrane elements, and is more suitable for industrial applications.

[0005] The inventors of the present invention have discovered through in-depth research that the method used in the prior art to modify the anti-pollution agent by passing it through membrane elements connected in series in sequence results in uneven modification effects on the membrane elements due to the system pressure distribution. Due to the uneven pressure distribution in each branch, some membrane elements cannot fully contact the anti-pollution agent, and thus the modification effects are also uneven. Therefore, the inventors control the number of membrane elements that can be installed in the membrane shell in the membrane shell unit of the device to between 1 and 3, and set a booster device between two adjacent membrane shells to accurately control the pressure and flow rate, thereby ensuring the consistency of the conditions of each membrane element during the anti-pollution modification process, thereby ensuring the anti-pollution performance of each anti-pollution reverse osmosis membrane element.

[0006] In order to achieve the above object, the present invention provides a method for preparing an anti-fouling reverse osmosis membrane element, which comprises the following steps:

[0007] (1) injecting an anti-pollution agent into a plurality of membrane shell units connected in parallel to modify the reverse osmosis membrane element, wherein each membrane shell unit comprises a plurality of membrane shells connected in series, and a booster device is provided between two adjacent membrane shells, and the pressure of each membrane shell is maintained between 2-3 bar by the booster device, and the number of reverse osmosis membrane elements in each membrane shell is 1-3;

[0008] (2) The modified reverse osmosis membrane element is circulated and flushed until the pH value of the discharged water after flushing is greater than 5.

[0009] Preferably, in step (1), the number of membrane shell units connected in parallel is 2-4.

[0010] Preferably, in step (1), each of the membrane shell units comprises 2-4 membrane shells connected in series.

[0011] Preferably, in step (1), the liquid inlet of each membrane shell is 7-9m 3 / h.

[0012] Preferably, in step (1), the modification process is continued for 30-180 min.

[0013] Preferably, in step (1), the anti-pollution agent contains polyvinyl alcohol at a concentration of 0.1-0.5 wt % and polymethacrylic acid at a concentration of 0.1-0.8 wt %.

[0014] Preferably, in step (2), pressurized water is injected into a plurality of parallel membrane shell units to circulate and flush the modified reverse osmosis membrane elements, wherein each of the membrane shell units comprises a plurality of membrane shells connected in series, and a boosting device is provided between two adjacent membrane shells, and the pressure of each membrane shell is maintained between 2-3 bar by the boosting device, and the number of reverse osmosis membrane elements in each membrane shell is 1-3.

[0015] Preferably, during the cyclic flushing process, the water inlet flow rate of each membrane shell is 7-9m 3 / h, the cyclic flushing process lasts for 5-30min, and the number of cycles is 3-5 times.

[0016] Preferably, in step (2), the flushing is circulated until the pH value of the water discharged after flushing is 5.1-7.5.

[0017] Preferably, the method is implemented in a treatment system, which includes: a first water tank for containing an anti-pollution agent, a second water tank for containing water, a filtering device, a water supply pump, a high-pressure pump and a treatment unit, the first water tank and the second water tank are respectively connected to the filtering device, the filtering device, the water supply pump, the high-pressure pump and the treatment unit are connected in sequence, and the treatment unit includes a plurality of parallel membrane shell units, each of the membrane shell units includes a plurality of membrane shells connected in series, and a boosting device is provided between two adjacent membrane shells, and the number of reverse osmosis membrane elements in each membrane shell is 1-3.

[0018] Preferably, during the modification process, an anti-pollution agent is supplied through the first water tank, the anti-pollution agent passes through the filtration device and the water supply pump, and is pressurized by the high-pressure pump and injected into the membrane shell unit to modify the reverse osmosis membrane element, and the anti-pollution agent used in the membrane shell unit is returned to the first water tank and then circulated to modify the reverse osmosis membrane element.

[0019] Preferably, during the circulation flushing process, water is supplied through the second water tank, the water passes through the filtration device and the water supply pump, and is pressurized by the high-pressure pump and injected into the membrane shell unit to flush the modified reverse osmosis membrane element, and the water used in the membrane shell unit is returned to the second water tank and then circulated for circulation flushing of the modified reverse osmosis membrane element.

[0020] The method of the present invention controls the number of membrane elements that can be installed in the membrane shell in the membrane shell unit of the device to between 1 and 3, and sets a booster device between two adjacent membrane shells to accurately control the pressure and flow rate, thereby ensuring the consistency of the conditions of each membrane element during the anti-pollution modification process, thereby ensuring the anti-pollution performance of the anti-pollution membrane element. This method has the characteristics of being able to stably prepare anti-pollution reverse osmosis membranes with excellent performance, can maximize the effect of ensuring the anti-pollution performance of the anti-pollution membrane element, and is more suitable for industrial applications. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 It is a schematic diagram of a device for preparing an anti-pollution reverse osmosis membrane element in the present invention.

[0022] Description of Reference Numerals

[0023] 1. First water tank; 2. Second water tank; 3. Filter device; 4. Water supply pump; 5. High-pressure pump; 6. Processing unit; 61. Membrane shell; 62. Pressurizing device. DETAILED DESCRIPTION

[0024] The specific embodiments of the present invention are described in detail below. It should be understood that the specific embodiments described herein are only used to illustrate and explain the present invention, and are not used to limit the present invention.

[0025] The endpoints and any values ​​of the ranges disclosed in this article are not limited to the precise ranges or values, and these ranges or values ​​should be understood to include values ​​close to these ranges or values. For numerical ranges, the endpoint values ​​of each range, the endpoint values ​​of each range and the individual point values, and the individual point values ​​can be combined with each other to obtain one or more new numerical ranges, which should be considered as specifically disclosed in this article.

[0026] In the description of this application, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating relative importance or implicitly indicating the number of technical features indicated. Therefore, unless otherwise specified, features defined as "first" and "second" may explicitly or implicitly include one or more of the features; "plurality" means two or more. The term "including" and any variation thereof means non-exclusive inclusion, and one or more other features, integers, steps, operations, units, components and / or combinations thereof may exist or be added.

[0027] In addition, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be internally connected between two components. For ordinary technicians in this field, the specific meanings of the above terms in this application can be understood according to specific circumstances.

[0028] The method for preparing the anti-pollution reverse osmosis membrane element of the present invention comprises the following steps:

[0029] (1) injecting an anti-pollution agent into a plurality of membrane shell units connected in parallel to modify the reverse osmosis membrane element, wherein each membrane shell unit comprises a plurality of membrane shells connected in series, and a booster device is provided between two adjacent membrane shells, and the pressure of each membrane shell is maintained between 2-3 bar by the booster device, and the number of reverse osmosis membrane elements in each membrane shell is 1-3;

[0030] (2) The modified reverse osmosis membrane element is circulated and flushed until the pH value of the discharged water after flushing is greater than 5.

[0031] In the method of the present invention, in step (1), the number of membrane shell units connected in parallel is preferably 2-4. In the present invention, by controlling the number of membrane shell units connected in parallel, the states of the membrane shell units are more easily kept consistent, the influence of external factors is reduced, and the modification results of the membrane shell units are ensured to be similar.

[0032] In the method of the present invention, in step (1), each of the membrane shell units includes 2-4 membrane shells connected in series. In the present invention, by controlling the number of membrane shells connected in series in the membrane shell unit, the states of the membrane shells are more easily kept consistent, the influence of external factors is reduced, and the modification results of the membrane shells are ensured to be similar.

[0033] In the method of the present invention, in step (1), the number of reverse osmosis membrane elements in each membrane shell is preferably 1-3. In the present invention, by controlling the number of reverse osmosis membrane elements in the membrane shell, the state of each reverse osmosis membrane element is more easily kept consistent, the influence of external factors is reduced, and the modification results of each reverse osmosis membrane element are ensured to be similar.

[0034] In the method of the present invention, in step (1), the liquid inflow of each membrane shell is 7-9m 3 / h.

[0035] In the method of the present invention, in step (1), the modification process is continued for 30-180 minutes.

[0036] In the method of the present invention, in step (1), the anti-pollution agent contains polyvinyl alcohol at a concentration of 0.1-0.5 wt % and polymethacrylic acid at a concentration of 0.1-0.8 wt %.

[0037] In the method described in the present invention, in step (2), water is pressurized and injected into a plurality of membrane shell units in parallel to circulate and flush the modified reverse osmosis membrane elements, wherein each of the membrane shell units includes a plurality of membrane shells connected in series, and a booster device is provided between two adjacent membrane shells, and the pressure of each membrane shell is maintained between 2-3 bar by the booster device, and the number of reverse osmosis membrane elements in each membrane shell is 1-3. In the present invention, the provision of a booster device can ensure that the pressure of each membrane shell is more uniform, and controlling the number of reverse osmosis membrane elements to 1-3 can make it easier to keep the state of each reverse osmosis membrane element consistent, reduce the influence of external factors, and ensure that the modification results of each reverse osmosis membrane element are similar.

[0038] In the method of the present invention, during the cyclic flushing process, the water inlet flow rate of each membrane shell can be 7-9m 3 / h, the cyclic flushing process can last for 5-30min, and the number of cycles can be 3-5 times. In a preferred embodiment, during the cyclic flushing process, the water inlet flow rate of each membrane shell is 7.5-8.5m 3 / h, the cyclic flushing process lasts for 10-25min, and the number of cycles can be 3-5 times.

[0039] In the method described in the present invention, in step (2), the cyclic flushing is performed until the pH value of the water discharged after flushing is 5.1-7.5.

[0040] In the method of the present invention, the method is implemented in a processing system such as Figure 1 As shown, the treatment system includes: a first water tank 1 for accommodating an anti-pollution agent, a second water tank 2 for accommodating water, a filtering device 3, a water supply pump 4, a high-pressure pump 5 and a processing unit 6, the first water tank 1 and the second water tank 2 are respectively connected to the filtering device 3, the filtering device 3, the water supply pump 4, the high-pressure pump 5 and the processing unit 6 are connected in sequence, and the processing unit 6 includes a plurality of parallel membrane shell units, each of which includes a plurality of series-connected membrane shells 61, and a booster device 62 is provided between two adjacent membrane shells 61, and the number of reverse osmosis membrane elements in each membrane shell 61 is 1-3; during the modification process, the anti-pollution agent is supplied through the first water tank 1, the The anti-pollution agent passes through the filtering device 3 and the water supply pump 4, and is pressurized by the high-pressure pump 5 and then injected into the membrane shell unit to modify the reverse osmosis membrane element, and the anti-pollution agent used in the membrane shell unit is returned to the first water tank 1, and then circulated to modify the reverse osmosis membrane element; during the circulating flushing process, water is supplied through the second water tank 2, and the water passes through the filtering device 3 and the water supply pump 4, and is pressurized by the high-pressure pump 5 and then injected into the membrane shell unit to flush the modified reverse osmosis membrane element, and the water used in the membrane shell unit is returned to the second water tank 2, and then circulated to flush the modified reverse osmosis membrane element.

[0041] In the method described in the present invention, the first water tank 1 and the second water tank 2 can be water tanks commonly used in the art, preferably PE material water tanks; the filter device 3 can be a filter device commonly used in the art, preferably a safety filter device; the water supply pump 4 and the high-pressure pump 5 can be booster pumps commonly used in the art, preferably fluoroplastic centrifugal pumps; the membrane shell 61 can be a common membrane shell in the art, preferably a low-pressure type 8040 membrane shell; the booster device 62 can be a booster pump commonly used in the art, preferably a fluoroplastic pipeline booster pump.

[0042] In the method described in the present invention, the treatment system also includes multiple on-site display instruments for pressure, temperature, and flow, as well as a pH meter, which are used to monitor the pressure, temperature, flow, and pH value of the discharged water in each pipeline during the preparation process, thereby ensuring the consistency of the preparation conditions of the reverse osmosis membrane element throughout the entire preparation process, thereby making the modification effect consistent and obtaining a reverse osmosis membrane element with excellent anti-pollution performance.

[0043] In the method of the present invention, the preparation device of the anti-pollution reverse osmosis membrane element is as follows Figure 1 As shown, the device includes a first water tank 1, a second water tank 2, a filtering device 3, a water supply pump 4, a high-pressure pump 5, a membrane shell 61, a boosting device 62, an on-site pressure display, an on-site temperature display and a pH meter. Among them, the first water tank 1 and the second water tank 2 are arranged in parallel and are connected to the filter device 3 through pipes respectively. An on-site flow display is arranged in front of the filter device 3 to monitor the flow of the solution in the pipe. Then the filter device 3, the water supply pump 4 and the high-pressure pump 5 are connected in series in sequence. Then the high-pressure pump 5 is connected to the processing unit 6. The processing unit 6 is 2-4 membrane shell units arranged in parallel. An on-site flow display is arranged at the front end of each membrane shell unit to monitor the flow of the solution in the pipe. 2-4 membrane shells 61 are connected in series in each membrane shell unit, and an on-site pressure display is arranged in front of each membrane shell 61 to monitor the real-time pressure. A boosting device 62 is arranged between every two membrane shells 61. Two pipes are arranged at the end of the membrane shell 61, so that the discharged water can be discharged or recycled into the water tank, and an on-site temperature display and a pH meter are arranged on the pipe to monitor the temperature and pH value of the discharged water.

[0044] The following examples further illustrate the method for preparing the anti-pollution reverse osmosis membrane element of the present invention. The examples are implemented based on the technical solution of the present invention, and provide detailed implementation methods and specific operation processes, but the protection scope of the present invention is not limited to the following examples.

[0045] The experimental methods in the following examples, unless otherwise specified, are all conventional methods in the art. The experimental materials used in the following examples, unless otherwise specified, are all commercially available.

[0046] Example 1

[0047] This embodiment Figure 1The treatment system shown is implemented, specifically, the treatment system includes a first water tank 1, a second water tank 2, a filter device 3, a water supply pump 4, a high-pressure pump 5 and a treatment unit 6, the first water tank 1 and the second water tank 2 are respectively connected to the filter device 3, the filter device 3, the water supply pump 4, the high-pressure pump 5 and the treatment unit 6 are connected in sequence, and the treatment unit 6 includes a plurality of parallel membrane shell units, each of the membrane shell units includes a plurality of membrane shells 61 connected in series, and a boosting device 62 is provided between two adjacent membrane shells 61.

[0048] The components of the anti-pollution agent in the first water tank 1 are: polyvinyl alcohol with a concentration of 0.5wt% and polymethacrylic acid with a concentration of 0.6wt%; the water used in the second water tank 2 is tap water; three membrane shell units are arranged in parallel in the processing unit 6, and three membrane shells 61 are connected in series in each membrane shell unit, and two reverse osmosis membrane elements are placed in each membrane shell 61, and a booster device 62 is arranged between two adjacent membrane shells 61, and the pressure of each membrane shell 61 is controlled by the booster device 62 to be 2.5bar, and the water inlet flow rate is 8m 3 / h.

[0049] (1) The anti-pollution agent passes through the filtering device 3 and the water supply pump 4 from the first water tank 1, and is then pressurized by the high-pressure pump 5 and injected into the treatment unit 6 to modify the reverse osmosis membrane element. The anti-pollution agent used in the treatment unit 6 is returned to the first water tank 1, and then circulated to modify the reverse osmosis membrane element. The modification time is 100 minutes;

[0050] (2) Tap water passes through the filter device 3 and the water supply pump 4 from the second water tank 2, and is then pressurized by the high-pressure pump 5 and injected into the treatment unit 6 to flush the modified reverse osmosis membrane element. The used water in the treatment unit 6 is returned to the second water tank 2, and then circulated to flush the modified reverse osmosis membrane element until the pH value of the discharged water after flushing is 6, and the flushing is stopped. The circulating flushing process is continued for 20 minutes, and the circulating flushing is repeated 4 times to obtain the anti-pollution reverse osmosis membrane element L1.

[0051] Example 2

[0052] The processing system is configured according to Example 1.

[0053] The components of the anti-pollution agent in the first water tank 1 are: polyvinyl alcohol with a concentration of 0.3wt% and polymethacrylic acid with a concentration of 0.8wt%; the water used in the second water tank 2 is tap water; 4 membrane shell units are arranged in parallel in the processing unit 6, 2 membrane shells 61 are connected in series in each membrane shell unit, 3 reverse osmosis membrane elements are placed in each membrane shell 61, and a booster device 62 is arranged between two adjacent membrane shells 61, and the pressure of each membrane shell 61 is controlled by the booster device 62 to be 3bar, and the water inlet flow rate is 7m3 / h.

[0054] (1) The anti-pollution agent passes through the filtering device 3 and the water supply pump 4 from the first water tank 1, and is then pressurized by the high-pressure pump 5 and injected into the treatment unit 6 to modify the reverse osmosis membrane element. The anti-pollution agent used in the treatment unit 6 is returned to the first water tank 1, and then circulated to modify the reverse osmosis membrane element. The modification time is 150 minutes.

[0055] (2) Tap water passes through the filter device 3 and the water supply pump 4 from the second water tank 2, and is then pressurized by the high-pressure pump 5 and injected into the treatment unit 6 to flush the modified reverse osmosis membrane element. The used water in the treatment unit 6 returns to the second water tank 2, and then is circulated to flush the modified reverse osmosis membrane element until the pH value of the discharged water after flushing is 7, and the flushing is stopped. The circulating flushing process is continued for 10 minutes, and the circulating flushing is repeated 5 times to obtain the anti-pollution reverse osmosis membrane element L2.

[0056] Example 3

[0057] The processing system is configured according to Example 1.

[0058] The components of the anti-pollution agent in the first water tank 1 are: polyvinyl alcohol with a concentration of 0.4wt% and polymethacrylic acid with a concentration of 0.7wt%; the water used in the second water tank 2 is tap water; two membrane shell units are arranged in parallel in the processing unit 6, and four membrane shells 61 are connected in series in each membrane shell unit, and one reverse osmosis membrane element is placed in each membrane shell 61, and a booster device 62 is arranged between two adjacent membrane shells 61, and the pressure of each membrane shell 61 is controlled by the booster device 62 to be 2bar, and the water inlet flow rate is 9m 3 / h.

[0059] (1) The anti-pollution agent passes through the filtering device 3 and the water supply pump 4 from the first water tank 1, and is then pressurized by the high-pressure pump 5 and injected into the treatment unit 6 to modify the reverse osmosis membrane element. The anti-pollution agent used in the treatment unit 6 is returned to the first water tank 1, and then circulated to modify the reverse osmosis membrane element. The modification time is 50 minutes.

[0060] (2) Tap water passes through the filter device 3 and the water supply pump 4 from the second water tank 2, and is then pressurized by the high-pressure pump 5 and injected into the treatment unit 6 to flush the modified reverse osmosis membrane element. The used water in the treatment unit 6 returns to the second water tank 2, and then is circulated to flush the modified reverse osmosis membrane element until the pH value of the discharged water after flushing is 7.5, and the flushing is stopped. The circulating flushing process is continued for 30 minutes, and the circulating flushing is repeated 3 times to obtain the anti-pollution reverse osmosis membrane element L3.

[0061] Comparative Example 1

[0062] The treatment system is configured according to Example 1, except that no pressure booster 62 is provided between two adjacent membrane shells 61, and the number of reverse osmosis membrane elements in each membrane shell 61 is 4. After the final treatment, a reverse osmosis membrane element D1 is obtained.

[0063] Test Example 1

[0064] The anti-pollution performance of the reverse osmosis membrane elements prepared in Examples 1-3 and Comparative Example 1 was tested. The test method is as follows: the contaminated reverse osmosis membrane is cleaned, and its contamination recovery rate F is measured using formula (1). The higher the contamination recovery rate (F) of the reverse osmosis membrane, the better its anti-pollution performance. The test results are shown in Table 1.

[0065]

[0066] Wherein, F (%) represents the pollution recovery rate of the reverse osmosis membrane; J0 is the initial flux of the reverse osmosis membrane, and J1 is the flux of the polluted reverse osmosis membrane after being cleaned.

[0067] Table 1

[0068]

[0069] Test Example 2

[0070] The anti-fouling performance test was performed on all the anti-fouling reverse osmosis membrane elements in the first membrane shell 61 in Example 1 and Comparative Example 1. The test results are shown in Table 2.

[0071] Table 2

[0072]

[0073] It can be seen from the results in Table 1 that the method for preparing anti-pollution reverse osmosis membrane elements of the present invention can be used to prepare anti-pollution reverse osmosis membrane elements with excellent performance in batches, and the anti-pollution performance of the prepared anti-pollution reverse osmosis membrane elements is obviously better, and the pollution recovery rate can be as high as 97% or more; and it can be seen from the data in Table 2 that the preparation method of the present invention can ensure that the anti-pollution performance of each anti-pollution reverse osmosis membrane element is equally excellent by accurately controlling the number of membrane elements that can be installed in the membrane shell in the membrane shell unit of the device as well as the pressure and flow rate. The difference in the pollution recovery rate of the anti-pollution reverse osmosis membrane is only 0.2, while the difference in the pollution recovery rate of the anti-pollution reverse osmosis membrane solved in the comparative example is as high as 6.8, and its stability is far worse than that of the present invention. Therefore, the method for preparing anti-pollution reverse osmosis membrane elements of the present invention solves the problem of uneven modification effect of membrane elements in the prior art, and can stably prepare anti-pollution reverse osmosis membranes with excellent performance in batches, which is more suitable for industrial applications.

[0074] The preferred embodiments of the present invention are described in detail above, but the present invention is not limited thereto. Within the technical concept of the present invention, the technical solution of the present invention can be subjected to a variety of simple modifications, including the combination of various technical features in any other suitable manner, and these simple modifications and combinations should also be regarded as the contents disclosed by the present invention and belong to the protection scope of the present invention.

Claims

1. A method for preparing an anti-pollution reverse osmosis membrane element, characterized in that: The method comprises the following steps: (1) The anti-pollution agent is pressurized and injected into a plurality of membrane shell units connected in parallel to modify the reverse osmosis membrane element, wherein each of the membrane shell units comprises a plurality of membrane shells connected in series, and a booster device is provided between two adjacent membrane shells, and the pressure of each membrane shell is maintained between 2-3 bar by the booster device, and the number of reverse osmosis membrane elements in each membrane shell is 1-3; (2) The modified reverse osmosis membrane element is circulated and flushed until the pH value of the discharged water after flushing is greater than 5.

2. The method according to claim 1, characterized in that In step (1), the number of membrane shell units connected in parallel is 2-4.

3. The method according to claim 1 or 2, characterized in that: In step (1), each of the membrane shell units comprises 2-4 membrane shells connected in series.

4. The method according to any one of claims 1 to 3, characterized in that: In step (1), the liquid inflow of each membrane shell is 7-9m 3 / h.

5. The method according to any one of claims 1 to 3, characterized in that: In step (1), the modification process is continued for 30-180 minutes.

6. The method according to any one of claims 1 to 3, characterized in that: In step (1), the anti-pollution agent contains polyvinyl alcohol at a concentration of 0.1-0.5 wt % and polymethacrylic acid at a concentration of 0.1-0.8 wt %.

7. The method according to claim 1, characterized in that In step (2), pressurized water is injected into a plurality of parallel membrane shell units to circulate and flush the modified reverse osmosis membrane elements, wherein each of the membrane shell units comprises a plurality of membrane shells connected in series, and a boosting device is provided between two adjacent membrane shells, and the pressure of each membrane shell is maintained between 2-3 bar by the boosting device, and the number of reverse osmosis membrane elements in each membrane shell is 1-3.

8. The method according to claim 7, characterized in that During the circulating flushing process, the water inlet flow rate of each membrane shell is 7-9m 3 / h, the cyclic flushing process lasts for 5-30min, and the number of cycles is 3-5 times.

9. The method according to claim 1, 7 or 8, characterized in that: In step (2), the flushing is circulated until the pH value of the water discharged after flushing is 5.1-7.

5.

10. The method according to any one of claims 1 to 9, characterized in that: The method is implemented in a treatment system, the treatment system comprising: a first water tank (1) for containing an anti-pollution agent, a second water tank (2) for containing water, a filtering device (3), a water supply pump (4), a high-pressure pump (5) and a treatment unit (6), the first water tank (1) and the second water tank (2) are respectively connected to the filtering device (3), the filtering device (3), the water supply pump (4), the high-pressure pump (5) and the treatment unit (6) are connected in sequence, and the treatment unit (6) comprises a plurality of membrane shell units connected in parallel, each of the membrane shell units comprises a plurality of membrane shells (61) connected in series, and a boosting device (62) is provided between two adjacent membrane shells (61), and the number of reverse osmosis membrane elements in each membrane shell (61) is 1-3; During the modification process, an anti-pollution agent is supplied through the first water tank (1), the anti-pollution agent passes through the filtering device (3) and the water supply pump (4), and is pressurized by the high-pressure pump (5) before being injected into the membrane shell unit to modify the reverse osmosis membrane element, and the anti-pollution agent used in the membrane shell unit is returned to the first water tank (1) and then circulated for modifying the reverse osmosis membrane element; During the circulation flushing process, water is supplied through the second water tank (2), the water passes through the filtering device (3) and the water supply pump (4), and is pressurized by the high-pressure pump (5) and injected into the membrane shell unit to flush the modified reverse osmosis membrane element, and the water used in the membrane shell unit is returned to the second water tank (2) and then circulated for circulation flushing of the modified reverse osmosis membrane element.

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