Reverse osmosis membrane cleaning agent composition, reverse osmosis membrane cleaning agent and its preparation method, application and usage method

Abstract

This invention relates to the field of environmental water treatment technology, and discloses a reverse osmosis membrane cleaning agent composition, a reverse osmosis membrane cleaning agent, its preparation method, application, and usage method. The composition contains the following components, stored independently or in combination: component A, component B, hydroxyethylidene diphosphonic acid, glycolic acid, nonionic surfactant, and water. The reverse osmosis membrane cleaning agent prepared using the composition provided by this invention can be applied to treat various types of membrane fouling with good results. Furthermore, the reverse osmosis cleaning agent provided by this invention also features a short cleaning cycle and high efficiency.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of environmental protection water treatment, and particularly relates to a reverse osmosis membrane cleaning agent composition, a reverse osmosis membrane cleaning agent, a preparation method, application and use method thereof. BACKGROUND

[0002] With the acceleration of industrial technology development, the use of industrial water is becoming more and more widespread, and the requirements for industrial water are becoming higher and higher. The raw water of many industrial water is municipal tap water, in order to save water cost, the reclaimed water or concentrated water of the water system will be reused. The quality of such water is relatively complex, the amount of bacteria and algae contained is relatively high, and the content of inorganic salt is also relatively high. In the treatment process, some microorganisms or colloidal particles will also breed.

[0003] Reverse osmosis membrane (DTRO membrane) treatment is an important process for wastewater treatment, and membrane pollution is a key factor affecting the normal operation of the reverse osmosis membrane system.

[0004] The pollution of reverse osmosis membrane includes adsorption of colloidal particles, inorganic scaling, organic pollution and breeding of microorganisms. After the reverse osmosis membrane is polluted, the system water production will decrease, the flux will decrease, the salt permeation rate will increase, and the membrane life will be greatly shortened, etc. If the reverse osmosis system that has been polluted to a certain extent is not cleaned in time, irreversible pollution of the membrane will easily occur.

[0005] CN106237864A discloses a reverse osmosis membrane cleaning agent and a use method thereof. The reverse osmosis membrane cleaning agent includes an alkaline reverse osmosis membrane cleaning agent and an acidic reverse osmosis membrane cleaning agent, and the alkaline reverse osmosis membrane cleaning agent and the acidic reverse osmosis membrane cleaning agent are independently stored. The mass percentage of each component of the alkaline reverse osmosis membrane cleaning agent is as follows: 0.8-4.0% metal chelating agent, 0.1-0.2% alkaline pH adjuster, 0.1-0.3% non-ionic surfactant, and the rest is solvent. The mass percentage of each component of the acidic reverse osmosis membrane cleaning agent is as follows: 0.1-0.2% citric acid, 0.1-0.2% acidic pH adjuster, and the rest is solvent. The use method is as follows: first, use the alkaline cleaning agent for cleaning, then rinse with clean water, and then use the acidic cleaning agent.

[0006] CN113750810A discloses a reverse osmosis membrane cleaning agent and a reverse osmosis membrane cleaning method. The reverse osmosis membrane cleaning agent includes an alkaline reverse osmosis membrane cleaning agent and / or an acidic reverse osmosis membrane cleaning agent. The alkaline reverse osmosis membrane cleaning agent includes a metal chelating agent, sodium sulfite, sodium hydroxide and a non-ionic surfactant. The acidic reverse osmosis membrane cleaning agent includes citric acid, ammonia, an acidic pH adjuster and a bacteriostatic agent.

[0007] Although the two reverse osmosis membrane cleaning agents have obvious cleaning effect, and to a certain extent, restore the water production of reverse osmosis system, reduce the operating pressure difference of reverse osmosis membrane, and prolong the service life of reverse osmosis membrane; but the reverse osmosis membrane cleaning agent needs to be used in combination with acidic and alkaline cleaning agents, resulting in long cleaning cycle and high cost of reagents; at the same time, the two cleaning agents are only effective for a certain type of pollution, and the application scene is single.

[0008] Therefore, it is of great significance to develop a membrane cleaning agent which can clean various reverse osmosis membrane pollutants and has high cleaning efficiency for the field of wastewater treatment. SUMMARY

[0009] The purpose of the present application is to solve the defects of the prior art reverse osmosis membrane cleaning agent, such as single application scene, poor applicability and long cleaning cycle.

[0010] In order to achieve the above purpose, the first aspect of the present application provides a reverse osmosis membrane cleaning agent composition, which contains the following components independently stored or mixed stored in two or more:

[0011] Component A, component B, hydroxyethylidene diphosphonic acid, glycolic acid, non-ionic surfactant, water;

[0012] The content of component A is 6-10wt%, the content of component B is 2-6wt%, the content of hydroxyethylidene diphosphonic acid is 12-18wt%, the content of glycolic acid is 6-10wt%, the content of non-ionic surfactant is 2-6wt%, and the content of water is 55-70wt% based on the total mass of the composition;

[0013] The component A is selected from at least one of disodium ethylenediaminetetraacetate, ethylenediaminetetraacetic acid and diethylenetriamine pentaacetic acid;

[0014] The component B is selected from at least one of 2,2-dibromo-3-nitrilo propionamide, dodecyl dimethyl benzyl ammonium chloride, dodecyl dimethyl benzyl ammonium bromide;

[0015] The non-ionic surfactant is a ternary combination surfactant, and the ternary combination surfactant contains alkyl phenol polyoxyethylene ether, secondary octanol polyoxyethylene ether and fatty alcohol polyoxyethylene ether with a mass ratio of 1-3:0.5-1:1.

[0016] The second aspect of the present application provides a method for preparing a reverse osmosis membrane cleaning agent, which comprises mixing the components in the composition of the first aspect, and the mixing conditions at least include: stirring speed of 100-150rpm, temperature of 10-40℃.

[0017] The third aspect of the present application provides the reverse osmosis membrane cleaning agent prepared by the method of the second aspect.

[0018] The fourth aspect of the present application provides the use of the reverse osmosis membrane cleaning agent of the third aspect in cleaning the reverse osmosis membrane containing pollutants.

[0019] The fifth aspect of the present application provides a method using the reverse osmosis membrane cleaning agent of the third aspect, which is used for cleaning the reverse osmosis membrane containing pollutants in a reverse osmosis system, comprising:

[0020] (1) performing a first cleaning on the reverse osmosis membrane containing pollutants with water until the sewage conductivity in the reverse osmosis system is not more than 2000 μS / cm or the time of the first cleaning is not less than 30 min;

[0021] (2) performing a second cleaning on the reverse osmosis membrane containing pollutants with the reverse osmosis membrane cleaning agent until the operating temperature of the reverse osmosis system is not more than 38℃;

[0022] (3) performing a third cleaning on the reverse osmosis membrane containing pollutants with water until the sewage conductivity in the reverse osmosis system is not more than 2000 μS / cm or the time of the third cleaning is not less than 30 min;

[0023] wherein the amount of the reverse osmosis membrane cleaning agent is controlled so that the pH value in the system is 2.5-3.5.

[0024] The present application forms a reverse osmosis membrane cleaning agent composition by synergistically compounding a ternary combination surfactant with a specific ratio, hydroxyacetic acid and hydroxyethylidene diphosphonic acid, and components A and B of a specific type, and the reverse osmosis membrane cleaning agent prepared by the composition can be applied to treat various types of membrane pollution such as metal oxide, microorganism, carbonate scale and sulfate scale, has wide applicability, and has the characteristics of short cleaning period and high cleaning efficiency. BRIEF DESCRIPTION OF DRAWINGS

[0025] Figure 1 is a surface state diagram of the reverse osmosis membrane containing iron oxide pollutants before cleaning;

[0026] Figure 2 is a surface state diagram of the reverse osmosis membrane containing iron oxide pollutants after cleaning with the reverse osmosis membrane cleaning agent prepared by the embodiment 1 of the present application;

[0027] Figure 3 is a surface state diagram of the reverse osmosis membrane containing carbonate scale pollutants before cleaning;

[0028] Figure 4 is a surface state diagram of the reverse osmosis membrane containing carbonate scale pollutants after cleaning with the reverse osmosis membrane cleaning agent prepared by the embodiment 1 of the present application;

[0029] Figure 5 is a surface state diagram of a reverse osmosis membrane containing sulfate scale contamination before cleaning;

[0030] Figure 6 is a surface state diagram of a reverse osmosis membrane containing sulfate scale contamination after cleaning with the reverse osmosis membrane cleaning agent prepared by the embodiment 1 of the present application;

[0031] Figure 7 is a surface state diagram of a reverse osmosis membrane containing microbial contamination before cleaning;

[0032] Figure 8 is a surface state diagram of a reverse osmosis membrane containing microbial contamination after cleaning with the reverse osmosis membrane cleaning agent prepared by the embodiment 1 of the present application;

[0033] Figure 9 is a process flow diagram of a preferred specific embodiment of the reverse osmosis system provided by the present application. DETAILED DESCRIPTION

[0034] The endpoints of the ranges and any values disclosed herein are not limited to the precise values stated. The endpoints of the ranges and any values are understood to be approximate values. Ranges include endpoints between the respective endpoints, between individual points and between the individual points within the ranges, and new ranges created by combining the endpoints and individual points. These new ranges are to be considered disclosed herein.

[0035] In the present application, unless otherwise specified, the room temperature or normal temperature means 25±2℃.

[0036] In the present application, unless otherwise specified, the CAS number of 2,2-dibromo-3-nitrilopropionamide is 10222-01-2.

[0037] In the present application, unless otherwise specified, the CAS number of hydroxyethylidene diphosphonic acid is 2809-21-4.

[0038] In the present application, unless otherwise specified, the hydroxyacetic acid is glycolic acid, and its CAS number is 79-14-1.

[0039] As described above, the first aspect of the present application provides a reverse osmosis membrane cleaning agent composition, which contains the following components stored independently or mixed together:

[0040] Component A, component B, hydroxyethylidene diphosphonic acid, hydroxyacetic acid, non-ionic surfactant, water;

[0041] The content of the component A is 6-10 wt%, the content of the component B is 2-6 wt%, the content of the hydroxyethylidene diphosphonic acid is 12-18 wt%, the content of the hydroxyacetic acid is 6-10 wt%, the content of the non-ionic surfactant is 2-6 wt%, and the content of the water is 55-70 wt% based on the total mass of the composition;

[0042] The component A is selected from at least one of disodium ethylenediaminetetraacetate, ethylenediaminetetraacetic acid and diethylenetriaminepentaacetic acid;

[0043] The component B is selected from at least one of 2,2-dibromo-3-nitrilopropionamide, dodecyl dimethyl benzyl ammonium chloride, dodecyl dimethyl benzyl ammonium bromide;

[0044] The non-ionic surfactant is a ternary combination surfactant, and the ternary combination surfactant contains alkylphenol polyoxyethylene ether, sec-octyl alcohol polyoxyethylene ether and fatty alcohol polyoxyethylene ether in a mass ratio of 1-3:0.5-1:1.

[0045] Preferably, the content of the component A is 6-8 wt%, the content of the component B is 2-4 wt%, the content of the hydroxyethylidene diphosphonic acid is 15-18 wt%, the content of the hydroxyacetic acid is 8-10 wt%, the content of the non-ionic surfactant is 3-6 wt%, and the content of the water is 60-66 wt% based on the total mass of the composition.

[0046] According to a particularly preferred specific embodiment, the component A is disodium ethylenediaminetetraacetate, the component B is 2,2-dibromo-3-nitrilopropionamide, and the content of the disodium ethylenediaminetetraacetate is 6-8 wt%, the content of the 2,2-dibromo-3-nitrilopropionamide is 2-4 wt%, the content of the hydroxyethylidene diphosphonic acid is 15-18 wt%, the content of the hydroxyacetic acid is 8-10 wt%, the content of the non-ionic surfactant is 3-6 wt%, and the content of the water is 60-66 wt% based on the total mass of the composition.

[0047] The present application synergistically compounds disodium ethylenediaminetetraacetate, 2,2-dibromo-3-nitrilopropionamide, hydroxyethylidene diphosphonic acid, hydroxyacetic acid and non-ionic surfactant, which not only can realize the dissolution of metal oxide, sulfate scale, carbonate scale and microbial membrane pollution, but also can effectively prevent the secondary pollution of the reverse osmosis membrane surface.

[0048] Preferably, the ternary combined surfactant contains alkylphenol polyoxyethylene ether, sec-octyl alcohol polyoxyethylene ether and fatty alcohol polyoxyethylene ether in a mass ratio of 1.5-2:0.8-1:1. The inventors have found that in this preferred case, the reverse osmosis membrane cleaning agent prepared can better achieve emulsification, penetration, wetting and dispersion of membrane pollutants, thereby achieving better cleaning effect.

[0049] According to a particularly preferred embodiment of the present application, the alkylphenol polyoxyethylene ether is selected from at least one of TX-10, TX-9 and TX-12.

[0050] According to a particularly preferred embodiment of the present application, the sec-octyl alcohol polyoxyethylene ether is selected from at least one of JFC-2, JFC-1 and JFC-E.

[0051] According to a particularly preferred embodiment of the present application, the fatty alcohol polyoxyethylene ether is selected from at least one of AEO-7, AEO-3 and AEO-9.

[0052] Preferably, the ternary combined surfactant contains TX-10, JFC-2 and AEO-7 in a mass ratio of 1.5-2:0.8-1:1. The inventors have found that in this preferred case, the reverse osmosis membrane cleaning agent prepared has higher cleaning efficiency.

[0053] As described above, the second aspect of the present application provides a method for preparing a reverse osmosis membrane cleaning agent, which comprises mixing the components in the composition of the first aspect, and the mixing conditions at least include: stirring speed of 100-150 rpm and temperature of 10-40℃.

[0054] It should be noted that the present application does not have special requirements for the feeding order and feeding mode of mixing the components in the composition, and known methods in the art can be used for feeding. For example, the present application can use water as a solvent, and then sequentially add component A, component B, hydroxyethylidene diphosphonic acid, hydroxyacetic acid and non-ionic surfactant.

[0055] In order to obtain better compounding effect, the present application should be fully stirred for 20-40 min between the feeding of the two components.

[0056] According to a particularly preferred embodiment of the present application, the operation of mixing the components in the composition of the first aspect comprises: mixing water with component A at a temperature of 10-40℃ at a speed of 100-150 rpm for 20-40 min, mixing with component B at a speed of 100-150 rpm for 20-40 min after adding component B, then adding hydroxyethylidene diphosphonic acid and stirring at 100-150 rpm for 20-40 min, then adding hydroxyacetic acid and stirring at 100-150 rpm for 20-40 min, and finally adding a non-ionic surfactant and stirring at 100-150 rpm for 20-40 min to obtain the reverse osmosis membrane cleaning agent.

[0057] As described above, the third aspect of the present application provides a reverse osmosis membrane cleaning agent prepared by the method of the second aspect.

[0058] According to a particularly preferred embodiment of the present application, the pH value of the reverse osmosis membrane cleaning agent is 2.5-3.5.

[0059] In actual use, the reverse osmosis membrane cleaning agent provided by the present application can obtain a pH value of 2.5-3.5 without the need to use acidic and alkaline cleaning agents in combination, and without the need to additionally add acidic or alkaline pH adjusters; and the reverse osmosis membrane cleaning agent prepared by the present application can realize cleaning and removal of various membrane pollutants such as metal oxides, microorganisms, carbonate scales and sulfate scales.

[0060] As described above, the fourth aspect of the present application provides the use of the reverse osmosis membrane cleaning agent of the third aspect in cleaning a reverse osmosis membrane containing pollutants.

[0061] Preferably, the pollutants are at least one selected from metal oxides, carbonate scales, sulfate scales, silicate scales, phosphate scales, sulfides, sulfur, and microorganisms.

[0062] According to a particularly preferred embodiment of the present application, the pollutants are at least one selected from metal oxides, carbonate scales, sulfate scales, and microorganisms.

[0063] Preferably, the metal oxides are at least one selected from iron oxides, magnetite, and aluminum oxides.

[0064] As described above, the fifth aspect of the present application provides a method for using the reverse osmosis membrane cleaning agent of the third aspect, which is used for cleaning a reverse osmosis membrane containing pollutants in a reverse osmosis system, and the method comprises:

[0065] (1) first cleaning of the reverse osmosis membrane containing pollutants with water until the sewage conductivity in the reverse osmosis system is not more than 2000 μS / cm or the first cleaning time is not less than 30 min;

[0066] (2) second cleaning of the reverse osmosis membrane containing pollutants with the reverse osmosis membrane cleaning agent until the operation temperature of the reverse osmosis system is not more than 38℃;

[0067] (3) third cleaning of the reverse osmosis membrane containing pollutants with water until the sewage conductivity in the reverse osmosis system is not more than 2000 μS / cm or the third cleaning time is not less than 30 min;

[0068] The amount of the reverse osmosis membrane cleaning agent is controlled so that the pH value in the system is 2.5-3.5.

[0069] It should be noted that before the first cleaning, the operation pressure, water conductivity and water flow rate data of the reverse osmosis system are recorded.

[0070] Preferably, the second cleaning method comprises: cyclic cleaning of the reverse osmosis membrane with the reverse osmosis membrane cleaning agent and static soaking of the reverse osmosis membrane in the reverse osmosis membrane cleaning agent.

[0071] The present application does not have special requirements for the type of reverse osmosis system, and any reverse osmosis system known in the art can be used. Exemplarily, the reverse osmosis system used in the present application is a disc tube reverse osmosis system as shown in the figure. Figure 9

[0072] The present application does not have special requirements for the specific operation method and times of the cyclic cleaning, and only needs to achieve the purpose of cleaning. Exemplarily, a preferred specific embodiment of the cyclic cleaning provided by the present application is described below. Figure 9 The cyclic cleaning comprises: injecting the reverse osmosis membrane cleaning agent into an intermediate cleaning tank, so that the reverse osmosis membrane cleaning agent sequentially passes through a centrifugal pre-boosting pump, a multi-medium filter, a high-pressure pump and an online boosting pump through a cleaning water inlet pipe and then contacts and cleans the reverse osmosis membrane assembly containing pollutants, a part of the cleaning liquid generated after cleaning is led out from the bottom of the reverse osmosis membrane assembly and recycled back to the front end of the online boosting pump, another part of the cleaning liquid is led out from the bottom of the reverse osmosis membrane assembly and recycled back to the intermediate cleaning tank for repeated use, and the cleaning water is led out from the side wall of the reverse osmosis membrane assembly and recycled back to the intermediate cleaning tank for repeated use; wherein the outlet pressure of the online boosting pump is 0.4-0.8 MPa.

[0073] The present application does not have special requirements for the specific operation method and times of the static soaking, and only needs to achieve the purpose of soaking. Exemplarily, a preferred specific embodiment of the static soaking provided by the present application is described below.​Figure 9 A preferred embodiment of the standing soak provided by the present application comprises that, after stopping the high-pressure pump and the online booster pump, the liquid level of the intermediate cleaning tank is higher than the liquid level of the reverse osmosis membrane module containing contaminants, so that the reverse osmosis membrane module containing contaminants is soaked in the reverse osmosis membrane cleaning agent.

[0074] It should be noted that, in the second cleaning process of the present application, the circulation cleaning and the standing soak are performed once as a cycle, and the judgment standard for the completion of the second cleaning can be that the operating temperature of the reverse osmosis system is not greater than 38℃, or that the second cleaning is performed for 5 cycles.

[0075] Preferably, the conditions of each circulation cleaning and each standing soak are each independently 0.5-2h in time.

[0076] The present application will be described in detail below through examples. In the following examples, various raw materials used are commercially available unless otherwise specified.

[0077] Component A: disodium ethylenediaminetetraacetate;

[0078] Component B: 2,2-dibromo-3-nitrilopropionamide;

[0079] Alkylphenol polyoxyethylene ether: TX-10, purchased from Jiangsu Lingfei Chemical Co., Ltd.;

[0080] Secondary octanol polyoxyethylene ether: JFC-2, purchased from Haian Petrochemical Co., Ltd.;

[0081] Fatty alcohol polyoxyethylene ether: AEO-7, purchased from BASF (China) Co., Ltd.;

[0082] In the following examples, 1 wt% means 250g;

[0083] Reverse osmosis membrane I: model SW30HRLE-400i, purchased from the United States Dow Chemical Company;

[0084] Reverse osmosis membrane II: model BW30FR-400 / 34i, purchased from the United States Dow Chemical Company.

[0085] Example 1

[0086] The present embodiment provides a method for preparing a reverse osmosis membrane cleaning agent, which comprises:

[0087] At room temperature, 60wt% of water was stirred at 120 rpm for 30 min, 8wt% of disodium ethylenediaminetetraacetate was stirred at 120 rpm for 30 min, 4wt% of 2,2-dibromo-3-nitrilopropionamide was stirred at 120 rpm for 30 min, 16wt% of hydroxyethanediphosphonic acid was stirred at 120 rpm for 30 min, 8wt% of hydroxyacetic acid was stirred at 120 rpm for 30 min, and finally 4wt% of a non-ionic surfactant (a ternary combination surfactant of alkylphenol polyoxyethylene ether, sec-octyl alcohol polyoxyethylene ether, and fatty alcohol polyoxyethylene ether with a mass ratio of 2:1:1) was stirred at 120 rpm for 30 min to obtain a reverse osmosis membrane cleaning agent S1.

[0088] Example 2

[0089] The present example provides a method for preparing a reverse osmosis membrane cleaning agent, which comprises:

[0090] At room temperature, 66wt% of water was stirred at 120 rpm for 30 min, 6wt% of disodium ethylenediaminetetraacetate was stirred at 120 rpm for 30 min, 2wt% of 2,2-dibromo-3-nitrilopropionamide was stirred at 120 rpm for 30 min, 15wt% of hydroxyethanediphosphonic acid was stirred at 120 rpm for 30 min, 8wt% of hydroxyacetic acid was stirred at 120 rpm for 30 min, and finally 3wt% of a non-ionic surfactant (a ternary combination surfactant of alkylphenol polyoxyethylene ether, sec-octyl alcohol polyoxyethylene ether, and fatty alcohol polyoxyethylene ether with a mass ratio of 2:1:1) was stirred at 120 rpm for 30 min to obtain a reverse osmosis membrane cleaning agent S2.

[0091] Example 3

[0092] The present example provides a method for preparing a reverse osmosis membrane cleaning agent, which comprises:

[0093] At room temperature, 62wt% of water was stirred at 120 rpm for 30 min, 7wt% of disodium ethylenediaminetetraacetate was stirred at 120 rpm for 30 min, 3wt% of 2,2-dibromo-3-nitrilopropionamide was stirred at 120 rpm for 30 min, 17wt% of hydroxyethanediphosphonic acid was stirred at 120 rpm for 30 min, 8wt% of hydroxyacetic acid was stirred at 120 rpm for 30 min, and finally 3wt% of a non-ionic surfactant (a ternary combination surfactant of alkylphenol polyoxyethylene ether, sec-octyl alcohol polyoxyethylene ether, and fatty alcohol polyoxyethylene ether with a mass ratio of 2:1:1) was stirred at 120 rpm for 30 min to obtain a reverse osmosis membrane cleaning agent S3.

[0094] Example 4

[0095] The reverse osmosis membrane cleaning agent was prepared according to the method of Example 1, except that the non-ionic surfactant contained alkylphenol polyoxyethylene ether, sec-octyl alcohol polyoxyethylene ether and fatty alcohol polyoxyethylene ether in a mass ratio of 1:1:1.

[0096] The remaining steps were the same as in Example 1 to obtain reverse osmosis membrane cleaning agent S4.

[0097] Example 5

[0098] The reverse osmosis membrane cleaning agent was prepared according to the method of Example 1, except that the non-ionic surfactant contained alkylphenol polyoxyethylene ether, sec-octyl alcohol polyoxyethylene ether and fatty alcohol polyoxyethylene ether in a mass ratio of 2:0.5:1.

[0099] The remaining steps were the same as in Example 1 to obtain reverse osmosis membrane cleaning agent S5.

[0100] Comparative Example 1

[0101] This comparative example provides a method for preparing a reverse osmosis membrane cleaning agent, which comprises:

[0102] At room temperature, 79wt% of water was stirred with 15wt% of hydrochloric acid at a speed of 120 rpm for 30 min, 2wt% of sodium dodecyl sulfate was added and stirred at a speed of 120 rpm for 30 min, then 4wt% of sodium bisulfite was added and stirred at 120 rpm for 30 min to obtain reverse osmosis membrane cleaning agent DS1.

[0103] Comparative Example 2

[0104] This comparative example provides a method for preparing a reverse osmosis membrane cleaning agent, which comprises:

[0105] At room temperature, 70wt% of water was stirred with 15wt% of citric acid at a speed of 120 rpm for 30 min, 10wt% of sulfamic acid was added and stirred at a speed of 120 rpm for 30 min, then 5wt% of sodium dodecylbenzenesulfonate was added and stirred at 120 rpm for 30 min to obtain reverse osmosis membrane cleaning agent DS2.

[0106] Comparative Example 3

[0107] This comparative example provides a method for preparing a reverse osmosis membrane cleaning agent, which comprises:

[0108] At room temperature, 76wt% of water was stirred with 15wt% of oxalic acid at a speed of 120 rpm for 30 min, 3wt% of isothiazole quinoline was added and stirred at a speed of 120 rpm for 30 min, then 5wt% of sodium chloride was added and stirred at 120 rpm for 30 min, finally 1wt% of sodium dodecyl sulfate was added and stirred at a speed of 120 rpm for 30 min, to obtain a reverse osmosis membrane cleaning agent DS3.

[0109] Comparative Example 4

[0110] The present comparative example provides a method for preparing a reverse osmosis membrane cleaning agent, which comprises:

[0111] At room temperature, 77.5wt% of water was stirred with 15wt% of sulfuric acid at a speed of 120 rpm for 30 min, 5wt% of sulfamic acid was added and stirred at a speed of 120 rpm for 30 min, then 2wt% of sodium chloride was added and stirred at 120 rpm for 30 min, finally 0.5wt% of fatty alcohol polyoxyethylene ether was added and stirred at a speed of 120 rpm for 30 min, to obtain a reverse osmosis membrane cleaning agent DS4.

[0112] Comparative Example 5

[0113] The present comparative example provides a method for preparing a reverse osmosis membrane cleaning agent, which comprises:

[0114] At room temperature, 57wt% of water was stirred with 20wt% of ethylenediaminetetraacetic acid at a speed of 120 rpm for 30 min, 15wt% of sodium tripolyphosphate was added and stirred at a speed of 120 rpm for 30 min, then 5wt% of sodium chloride was added and stirred at 120 rpm for 30 min, finally 3wt% of sodium dodecyl sulfate was added and stirred at a speed of 120 rpm for 30 min, to obtain a reverse osmosis membrane cleaning agent DS5.

[0115] Test Example 1

[0116] The reverse osmosis membrane cleaning agents prepared in the examples and comparative examples were applied to clean the reverse osmosis membrane I containing iron oxide contaminants, and the specific results are shown in Table 1.

[0117] The cleaning method was as follows:

[0118] The working pressure of the reverse osmosis system at 25°C before cleaning was recorded as 6 MPa, the water production flow rate was 2.2 m 3 / h, and the product water conductivity was 2041 μS / cm; the reverse osmosis membrane I containing contaminants was first cleaned with deionized water until the sewage conductivity in the reverse osmosis system was not greater than 2000 μS / cm;

[0119] Then the reverse osmosis membrane I containing iron oxide pollutants is cleaned with the reverse osmosis membrane cleaning agent respectively for a second time until the operating temperature of the reverse osmosis system reaches 38℃; wherein the amount of the reverse osmosis membrane cleaning agent is controlled so that the pH value in the system is 3;

[0120] Finally, the reverse osmosis membrane I containing iron oxide pollutants is cleaned with deionized water for a third time until the wastewater conductivity in the reverse osmosis system is not more than 2000 μS / cm, the working pressure of the reverse osmosis system at 25℃ after cleaning with the reverse osmosis membrane cleaning agent is recorded respectively, the water production flow rate and the water production conductivity are recorded, and the membrane flux recovery rate is calculated.

[0121] Wherein the membrane flux recovery rate = (water production flow rate after the reverse osmosis membrane cleaning agent prepared in different examples is treated by the foregoing cleaning method / 3) * 100%.

[0122] Table 1

[0123]

[0124]

[0125] From the results in Table 1, it can be seen that the reverse osmosis membrane cleaning agent provided by the present application has good cleaning effect on metal oxides and does not cause damage to the reverse osmosis system.

[0126] The present application exemplarily provides the surface state contrast chart of the reverse osmosis membrane containing iron oxide pollutants before and after cleaning with the reverse osmosis membrane cleaning agent prepared in Example 1, which are respectively shown in Figure 1 and Figure 2 .

[0127] Wherein, Figure 1 is the surface state chart of the reverse osmosis membrane containing iron oxide pollutants before cleaning, Figure 2 is the surface state chart of the reverse osmosis membrane containing iron oxide pollutants after cleaning with the reverse osmosis membrane cleaning agent prepared in Example 1 of the present application.

[0128] From Figure 1 and Figure 2 , it can be seen that after cleaning with the reverse osmosis membrane cleaning agent provided by the present application, the iron oxide pollutants on the surface of the reverse osmosis membrane are almost completely cleaned.

[0129] Test Example 2

[0130] The reverse osmosis membrane cleaning agent prepared in the examples and comparative examples is applied to clean the reverse osmosis membrane I containing carbonate scale pollutants, and the specific results are shown in Table 2.

[0131] The specific cleaning method refers to the cleaning method in Test Example 1, and the working pressure of the reverse osmosis system at 25℃ before cleaning is 5.8 MPa, the water production flow rate is 1.5 m 3 / h, and the water production conductivity is 3026 μS / cm.

[0132] The working pressure, water production flow rate and water production conductivity of the reverse osmosis system at 25℃ after cleaning with the reverse osmosis membrane cleaning agent are recorded respectively, and the membrane flux recovery rate is calculated.

[0133] The membrane flux recovery rate = (water production flow rate of the reverse osmosis membrane cleaning agent prepared in different examples using the foregoing cleaning method / 3) * 100%.

[0134] Table 2

[0135]

[0136]

[0137] As can be seen from the results in Table 2, the reverse osmosis membrane cleaning agent provided by the present application has good cleaning effect on carbonate scale pollutants, and will not cause damage to the reverse osmosis system.

[0138] The present application exemplarily provides a comparison chart of the surface state of the reverse osmosis membrane containing carbonate scale pollutants before and after cleaning with the reverse osmosis membrane cleaning agent prepared in Example 1, which are respectively shown in Figure 3 and Figure 4 .

[0139] The surface state chart of the reverse osmosis membrane containing carbonate scale pollutants before cleaning is Figure 3 , and the surface state chart of the reverse osmosis membrane containing carbonate scale pollutants after cleaning with the reverse osmosis membrane cleaning agent prepared in Example 1 of the present application is Figure 4 .

[0140] As can be seen from Figure 3 and Figure 4 , the reverse osmosis membrane cleaning agent provided by the present application can effectively dissolve carbonate scale pollutants, so that the carbonate scale pollutants on the surface of the reverse osmosis membrane are cleaned.

[0141] Test Example 3

[0142] The reverse osmosis membrane cleaning agents prepared in the examples and comparative examples are applied to clean the reverse osmosis membrane II containing sulfate scale pollutants, and the specific results are shown in Table 3.

[0143] The specific cleaning method refers to the cleaning method in Test Example 1, and the working pressure of the reverse osmosis system at 25℃ before cleaning is 6.2 MPa, the water production flow rate is 1.8 m 3 / h, and the water production conductivity is 1046 μS / cm.

[0144] Record the working pressure, water production flow rate and water conductivity of the reverse osmosis system at 25℃ after cleaning with the reverse osmosis membrane cleaning agent, and calculate the membrane flux recovery rate.

[0145] The membrane flux recovery rate = (water production flow rate of the reverse osmosis membrane cleaning agent prepared in different examples using the aforementioned cleaning method / 3.5) * 100%.

[0146] Table 3

[0147]

[0148]

[0149] As can be seen from the results in Table 3, the reverse osmosis membrane cleaning agent provided by the present application has good cleaning effect on sulfate scale pollutants, and does not cause damage to the reverse osmosis system.

[0150] The present application exemplarily provides a comparison chart of the surface state of the reverse osmosis membrane containing sulfate scale pollutants before and after cleaning with the reverse osmosis membrane cleaning agent prepared in Example 1, which are respectively shown in Figure 5 and Figure 6 .

[0151] The surface state of the reverse osmosis membrane containing sulfate scale pollutants before cleaning is shown in Figure 5 , and the surface state of the reverse osmosis membrane containing sulfate scale pollutants after cleaning with the reverse osmosis membrane cleaning agent prepared in Example 1 of the present application is shown in Figure 6 .

[0152] As can be seen from Figure 5 and Figure 6 , the reverse osmosis membrane cleaning agent provided by the present application has good removal effect on the sulfate scale pollutants on the surface of the reverse osmosis membrane.

[0153] Test Example 4

[0154] The reverse osmosis membrane cleaning agents prepared in the examples and comparative examples are applied to clean the reverse osmosis membrane II containing microbial pollutants, and the specific results are shown in Table 4.

[0155] The specific cleaning method refers to the cleaning method in Test Example 1, and the working pressure of the reverse osmosis system at 25℃ before cleaning is 6.6 MPa, the water production flow rate is 2 m 3 / h, and the water conductivity is 2866 μS / cm.

[0156] Record the working pressure, water production flow rate and water conductivity of the reverse osmosis system at 25℃ after cleaning with the reverse osmosis membrane cleaning agent, and calculate the membrane flux recovery rate.

[0157] The membrane flux recovery rate = (water production flow rate of the reverse osmosis membrane cleaning agent prepared by different examples using the aforementioned cleaning method / 3.5) * 100%.

[0158] Table 4

[0159]

[0160]

[0161] As can be seen from the results in Table 4, the reverse osmosis membrane cleaning agent provided by the present application can penetrate the cell membrane of microorganisms, stop the normal oxidation and reduction of cells, and ultimately cause the death of microorganisms, thereby achieving good cleaning effect on microorganisms.

[0162] The present application exemplarily provides a comparison chart of the surface state of the reverse osmosis membrane containing microbial contamination before and after cleaning using the reverse osmosis membrane cleaning agent prepared in Example 1, which are respectively shown in Figure 7 and Figure 8 .

[0163] wherein, Figure 7 is a surface state chart of the reverse osmosis membrane containing microbial contamination before cleaning, Figure 8 is a surface state chart of the reverse osmosis membrane containing microbial contamination after cleaning using the reverse osmosis membrane cleaning agent prepared in Example 1 of the present application.

[0164] As can be seen from Figure 7 and Figure 8 , the surface of the reverse osmosis membrane after cleaning is very clean, and it can be seen that the reverse osmosis membrane cleaning agent provided by the present application can effectively clean the microorganisms on the surface of the reverse osmosis membrane.

[0165] The preferred embodiments of the present application are described in detail above, but the present application is not limited thereto. Within the technical concept of the present application, various simple modifications can be made to the technical solutions of the present application, including the combination of various technical features in any other suitable manner, and these simple modifications and combinations should also be considered as disclosed by the present application and fall within the protection scope of the present application.

Claims

1. A reverse osmosis membrane cleaning agent composition characterized in that, The composition contains the following components which are independently stored or mixed together: Component A, component B, hydroxyethylidene diphosphonic acid, hydroxyacetic acid, non-ionic surfactant, water; The content of the component A is 6-10wt%, the content of the component B is 2-6wt%, the content of the hydroxyethylidene diphosphonic acid is 12-18wt%, the content of the hydroxyacetic acid is 6-10wt%, the content of the non-ionic surfactant is 2-6wt%, and the content of the water is 55-70wt% based on the total mass of the composition; The component A is selected from at least one of disodium ethylenediaminetetraacetate, ethylenediaminetetraacetic acid and diethylenetriaminepentaacetic acid; The component B is selected from at least one of 2,2-dibromo-3-nitrilopropionamide, dodecyl dimethyl benzyl ammonium chloride, dodecyl dimethyl benzyl ammonium bromide; The non-ionic surfactant is a ternary combination surfactant, and the ternary combination surfactant contains alkylphenol polyoxyethylene ether, sec-octyl alcohol polyoxyethylene ether and fatty alcohol polyoxyethylene ether with a mass ratio of 1.5-2:0.8-1:

1.

2. The composition of claim 1, wherein, The content of the component A is 6-8wt%, the content of the component B is 2-4wt%, the content of the hydroxyethylidene diphosphonic acid is 15-18wt%, the content of the hydroxyacetic acid is 8-10wt%, the content of the non-ionic surfactant is 3-6wt%, and the content of the water is 60-66wt% based on the total mass of the composition.

3. The composition according to claim 1 or 2, wherein, The alkylphenol polyoxyethylene ether is selected from at least one of TX-10, TX-9 and TX-12.

4. The composition of claim 1 or 2, wherein, The sec-octyl alcohol polyoxyethylene ether is selected from at least one of JFC-2, JFC-1 and JFC-E.

5. The composition of claim 1 or 2, wherein, The fatty alcohol polyoxyethylene ether is selected from at least one of AEO-7, AEO-3 and AEO-9.

6. The composition of claim 1 or 2, wherein, The ternary combination surfactant contains a combination of TX-10, JFC-2 and AEO-7 with a mass ratio of 1.5-2:0.8-1:

1.

7. A method of preparing a reverse osmosis membrane cleaning agent, characterized by, The method comprises mixing the components in the composition of any one of claims 1-6, and the mixing conditions at least include a stirring speed of 100-150rpm and a temperature of 10-40℃.

8. The reverse osmosis membrane cleaning agent prepared by the method of claim 7.

9. The reverse osmosis membrane cleaning agent of claim 8, wherein, The pH value of the reverse osmosis membrane cleaning agent is 2.5-3.

5.

10. The use of the reverse osmosis membrane cleaning agent of claim 8 or 9 in cleaning a reverse osmosis membrane containing pollutants.

11. Use according to claim 10, wherein, The pollutants are selected from at least one of metal oxides, carbonate scales, sulfate scales, silicate scales, phosphate scales, sulfides, sulfur and microorganisms.

12. A method of using the reverse osmosis membrane cleaning agent of claim 8 or 9, characterized by, The method for cleaning a reverse osmosis membrane containing pollutants in a reverse osmosis system comprises: (1) performing a first cleaning on the reverse osmosis membrane containing pollutants with water until the wastewater conductivity in the reverse osmosis system is not greater than 2000μS / cm or the first cleaning time is not less than 30min; (2) performing a second cleaning of the reverse osmosis membrane containing the pollutants with the reverse osmosis membrane cleaning agent until the operating temperature of the reverse osmosis system is not more than 38℃; (3) performing a third cleaning of the reverse osmosis membrane containing the pollutants with water until the sewage conductivity in the reverse osmosis system is not more than 2000 μS / cm or the third cleaning time is not less than 30 min; wherein the amount of the reverse osmosis membrane cleaning agent is controlled so that the pH value in the system is 2.5-3.5.

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