Reverse osmosis membrane silicon scale cleaning agent formula

Abstract

The invention discloses a reverse osmosis membrane silicon scale cleaning agent formula which comprises the following components in percentage by mass: 10-25% of an inorganic acid cleaning agent, 1-5% of a dispersing agent, 2-8% of an inorganic surfactant, 0.1-0.5% of a corrosion inhibitor, 3-10% of a multivalent chelating agent, 1-5% of a defoaming agent, 0.1-0.5% of a stabilizer and the balance of a pH regulator. The cleaning agent comprises the following components in percentage by weight: 0.1-0.3% of a defoaming agent, 0.1-0.3% of a stabilizer, 0.1-0.5% of a pH regulator The method has the beneficial effects that silicon scale on the surface of the reverse osmosis membrane can be efficiently removed, the filtering performance and the water permeability of the membrane are recovered, meanwhile, membrane elements are prevented from being damaged, and the safety and the purity of water are guaranteed; the cleaning agent provided by the invention has the advantages of environmental protection, safety, good stability and the like, and is suitable for cleaning various reverse osmosis membrane silicon scales.

Description

Technical Field

[0001] The invention belongs to the technical field of reverse osmosis membrane silicon scale cleaning, and in particular relates to a formula of a reverse osmosis membrane silicon scale cleaning agent. Background Art

[0002] Reverse osmosis membrane is a special semi-permeable membrane that plays a vital role in the field of water treatment. Reverse osmosis membrane can intercept soluble salts in water, such as sodium chloride, magnesium chloride, etc., to achieve desalination effect. In the process of seawater desalination and brackish water desalination, reverse osmosis membrane plays a key role and provides people with valuable fresh water resources. Reverse osmosis membrane can also effectively remove bacteria, viruses, organic matter, heavy metal ions and other impurities in water to improve the purity of water quality. Reverse osmosis membrane is widely used in drinking water treatment, wastewater reuse, medical water, ultrapure water for electronics industry and other fields. Compared with traditional desalination technologies such as ion exchange and electrodialysis, reverse osmosis membrane technology has higher energy efficiency and lower energy consumption. At the same time, reverse osmosis membrane also has the advantages of simple operation, small footprint and strong adaptability.

[0003] The main reason for the silica scale on the reverse osmosis membrane is that the soluble silica in the water undergoes polymerization reaction after reaching the supersaturated state, forming insoluble silica colloids, which are then deposited on the membrane surface to form silica scale.

[0004] The cleaning of silica scale on the reverse osmosis membrane is based on the following considerations: the formation of silica scale will cause the water output of the reverse osmosis membrane element to decrease. By cleaning and removing the silica scale, the water output of the membrane element can be restored to ensure the normal operation of the system; the long-term presence of silica scale will damage the reverse osmosis membrane and shorten the service life of the membrane. Regular cleaning can effectively remove the silica scale and extend the service life of the membrane; silica scale contains harmful substances such as bacteria and viruses, which pose a threat to water safety. By cleaning and removing the silica scale, the safety and purity of the water quality can be guaranteed; the presence of silica scale will increase the operating resistance of the system and reduce the efficiency of the system. After cleaning and removing the silica scale, the operating resistance of the system is reduced and the efficiency is improved.

[0005] A reverse osmosis membrane silicon scale cleaning agent with publication number CN114504948B and a preparation method thereof, the patent discloses that, by mass percentage, the organic acid cleaning agent accounts for 10%-25%, the synergist accounts for 3%-5%, the dispersant accounts for 1%-5%, the corrosion inhibitor accounts for 0.2%-0.3%, the surfactant accounts for 2%-5%, and the balance is deionized water, the organic acid cleaning agent is one or more of aminosulfonic acid, citric acid, and ammonium citrate, the synergist is one or more of ammonium bifluoride and sodium fluoride, the dispersant is one or more of aminotrimethylenephosphonic acid, polyacrylic acid, and tannin, the corrosion inhibitor is one or more of urotropine and thiourea, which can effectively remove silicon scale on the surface of the reverse osmosis membrane without causing secondary pollution or damaging the membrane element, and the membrane flux can be effectively restored; however, with the continuous development of water treatment technology, the performance requirements for cleaning agents are getting higher and higher, and it is necessary to develop more efficient, environmentally friendly and safe cleaning agents. Summary of the invention

[0006] The purpose of the present invention is to provide a formula for a reverse osmosis membrane silicon scale cleaning agent, wherein the ingredients in the cleaning agent are all environmentally friendly chemicals, which will not pollute the environment and will not cause harm to the human body.

[0007] To achieve the above-mentioned purpose, the present invention provides the following technical scheme: a formula of a reverse osmosis membrane silicon scale cleaning agent, comprising an inorganic acid cleaning agent, a dispersant, an inorganic surfactant, a corrosion inhibitor, a multivalent chelating agent, a defoaming agent, a stabilizer, and a pH regulator, wherein the components thereof are calculated by mass percentage as follows: 10-25% of an inorganic acid cleaning agent, 1-5% of a dispersant, 2-8% of an inorganic surfactant, 0.1-0.5% of a corrosion inhibitor, 3-10% of a multivalent chelating agent, 0.1-0.3% of a defoaming agent, 0.1-0.3% of a stabilizer, 0.1-0.5% of a pH regulator, and the balance being deionized water.

[0008] As a preferred technical solution of the present invention, the inorganic acid cleaning agent is sulfuric acid.

[0009] As a preferred technical solution of the present invention, the inorganic surfactant is sodium tripolyphosphate.

[0010] As a preferred technical solution of the present invention, the multivalent chelating agent is tetrasodium ethylenediaminetetraacetic acid.

[0011] As a preferred technical solution of the present invention, the dispersant is one or a combination of polyacrylic acid and polycarboxylate.

[0012] As a preferred technical solution of the present invention, the corrosion inhibitor is one of nitrite, silicate and benzotriazole.

[0013] As a preferred technical solution of the present invention, the defoaming agent is one of silicone oil and polyether.

[0014] As a preferred technical solution of the present invention, the stabilizer is one of sodium nitrite and sodium sulfite.

[0015] As a preferred technical solution of the present invention, the pH regulator is one of ammonia water and sodium hydroxide.

[0016] Compared with the prior art, the present invention has the following beneficial effects:

[0017] It can effectively remove the silica scale on the surface of the reverse osmosis membrane, restore the filtration performance and water permeability of the membrane, avoid damage to the membrane elements, and ensure the safety and purity of the water quality;

[0018] The cleaning agent of the present invention has the advantages of being environmentally friendly, safe, and having good stability, and is suitable for cleaning silicon scale on various reverse osmosis membranes. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 The present invention is a flow chart for preparing the reverse osmosis membrane silicon scale cleaning agent. DETAILED DESCRIPTION

[0020] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0021] Example 1

[0022] See also Figure 1 , which is the first embodiment of the present invention, and provides a formula for a reverse osmosis membrane silicon scale cleaning agent, including an inorganic acid cleaning agent, a dispersant, an inorganic surfactant, a corrosion inhibitor, a multivalent chelating agent, a defoaming agent, a stabilizer, and a pH regulator, wherein the components are calculated by mass percentage as follows: 10% inorganic acid cleaning agent, 1% dispersant, 2% inorganic surfactant, 0.1% corrosion inhibitor, 3% multivalent chelating agent, 0.1% defoaming agent, 0.1% stabilizer, 0.1% pH regulator, and the balance is deionized water, wherein the inorganic acid cleaning agent is sulfuric acid, the inorganic surfactant is sodium tripolyphosphate; the multivalent chelating agent is tetrasodium glutamate diacetate (GLDA); the dispersant is polyacrylic acid; the corrosion inhibitor is nitrite; the defoaming agent is silicone oil; the stabilizer is sodium nitrite; and the pH regulator is aqueous ammonia.

[0023] Inorganic acid cleaners, as the main component of cleaning agents, can effectively dissolve and remove silica scale;

[0024] Dispersants can disperse and suspend silica scale particles to prevent them from redepositing on the membrane surface;

[0025] Inorganic surfactants can reduce the surface tension of water and enhance the penetration and wetting properties of cleaning agents;

[0026] Corrosion inhibitors can slow down the corrosion of cleaning agents on membrane elements and extend the service life of the membrane;

[0027] The multivalent sequestrant can combine with the metal ions in the silica scale to form a stable chelate, thus helping to remove the silica scale;

[0028] Defoaming agent can eliminate the foam generated by the cleaning agent during the cleaning process and improve the cleaning efficiency;

[0029] Stabilizers can maintain the stability of cleaning agents and prevent them from decomposing or deteriorating during storage and use;

[0030] PH regulator can adjust the pH of the cleaning agent to adapt it to the cleaning needs of different membrane elements;

[0031] Deionized water can dissolve and dilute the above ingredients to form a uniform cleaning solution.

[0032] The preparation method of reverse osmosis membrane silicon scale cleaning agent is as follows:

[0033] Deionized water was added into the reactor and heated to 35°C to maintain a constant temperature during the mixing process;

[0034] Add the required amount of inorganic acid cleaning agent into the reactor under stirring to avoid local overheating or splashing;

[0035] Continue stirring and gradually add the dispersant and inorganic surfactant to ensure that they are evenly dispersed in the solution;

[0036] Then add the corrosion inhibitor and the sequestrant, also keeping stirring to mix thoroughly;

[0037] Adding defoamers and stabilizers to the solution to improve the foam performance and stability of the solution;

[0038] Use a pH regulator to gradually adjust the pH of the solution to the desired range;

[0039] After all components are added, continue stirring for 10 minutes to ensure that all components are fully mixed and reach a uniform state.

[0040] Example 2

[0041] See also Figure 1, which is the second embodiment of the present invention, and provides a formula for a reverse osmosis membrane silicon scale cleaning agent, including an inorganic acid cleaning agent, a dispersant, an inorganic surfactant, a corrosion inhibitor, a multivalent chelating agent, a defoaming agent, a stabilizer, and a pH regulator, wherein the components are calculated by mass percentage as follows: 18% inorganic acid cleaning agent, 3% dispersant, 5% inorganic surfactant, 0.3% corrosion inhibitor, 7% multivalent chelating agent, 0.2% defoaming agent, 0.2% stabilizer, 0.3% pH regulator, and the balance is deionized water, wherein the inorganic acid cleaning agent is sulfuric acid, the inorganic surfactant is sodium tripolyphosphate; the multivalent chelating agent is tetrasodium glutamate diacetate (GLDA); the dispersant is a polycarboxylate; the corrosion inhibitor is a silicate; the defoaming agent is a polyether; the stabilizer is sodium sulfite; and the pH regulator is sodium hydroxide.

[0042] Inorganic acid cleaners, as the main component of cleaning agents, can effectively dissolve and remove silica scale;

[0043] Dispersants can disperse and suspend silica scale particles to prevent them from redepositing on the membrane surface;

[0044] Inorganic surfactants can reduce the surface tension of water and enhance the penetration and wetting properties of cleaning agents;

[0045] Corrosion inhibitors can slow down the corrosion of cleaning agents on membrane elements and extend the service life of the membrane;

[0046] The multivalent sequestrant can combine with the metal ions in the silica scale to form a stable chelate, thus helping to remove the silica scale;

[0047] Defoaming agent can eliminate the foam generated by the cleaning agent during the cleaning process and improve the cleaning efficiency;

[0048] Stabilizers can maintain the stability of cleaning agents and prevent them from decomposing or deteriorating during storage and use;

[0049] PH regulator can adjust the pH of the cleaning agent to adapt it to the cleaning needs of different membrane elements;

[0050] Deionized water can dissolve and dilute the above ingredients to form a uniform cleaning solution.

[0051] The preparation method of reverse osmosis membrane silicon scale cleaning agent is as follows:

[0052] Deionized water was added into the reactor and heated to 40°C to maintain a constant temperature during the mixing process;

[0053] Add the required amount of inorganic acid cleaning agent into the reactor under stirring to avoid local overheating or splashing;

[0054] Continue stirring and gradually add the dispersant and inorganic surfactant to ensure that they are evenly dispersed in the solution;

[0055] Then add the corrosion inhibitor and the sequestrant, also keeping stirring to mix thoroughly;

[0056] Adding defoamers and stabilizers to the solution to improve the foam performance and stability of the solution;

[0057] Use a pH regulator to gradually adjust the pH of the solution to the desired range;

[0058] After all components are added, continue stirring for 20 minutes to ensure that all components are fully mixed and reach a uniform state.

[0059] Example 3

[0060] See also Figure 1 , which is the third embodiment of the present invention, and provides a formula for a reverse osmosis membrane silicon scale cleaning agent, including an inorganic acid cleaning agent, a dispersant, an inorganic surfactant, a corrosion inhibitor, a multivalent chelating agent, a defoaming agent, a stabilizer, and a pH regulator, wherein the components are calculated by mass percentage as follows: 25% inorganic acid cleaning agent, 5% dispersant, 8% inorganic surfactant, 0.5% corrosion inhibitor, 10% multivalent chelating agent, 0.3% defoaming agent, 0.3% stabilizer, 0.5% pH regulator, and the balance is deionized water, wherein the inorganic acid cleaning agent is sulfuric acid, the inorganic surfactant is sodium tripolyphosphate; the multivalent chelating agent is tetrasodium glutamate diacetate (GLDA); the dispersant is one or a combination of two of polyacrylic acid and polycarboxylate; the corrosion inhibitor is benzotriazole; the defoaming agent is silicone oil; the stabilizer is sodium nitrite; and the pH regulator is aqueous ammonia.

[0061] The preparation method of reverse osmosis membrane silicon scale cleaning agent is as follows:

[0062] Deionized water was added into the reactor and heated to 45°C to maintain a constant temperature during the mixing process;

[0063] Add the required amount of inorganic acid cleaning agent into the reactor under stirring to avoid local overheating or splashing;

[0064] Continue stirring and gradually add the dispersant and inorganic surfactant to ensure that they are evenly dispersed in the solution;

[0065] Then add the corrosion inhibitor and the sequestrant, also keeping stirring to mix thoroughly;

[0066] Adding defoamers and stabilizers to the solution to improve the foam performance and stability of the solution;

[0067] Use a pH regulator to gradually adjust the pH of the solution to the desired range;

[0068] After all components are added, continue stirring for 30 minutes to ensure that all components are fully mixed and reach a uniform state.

[0069] Inorganic acid cleaners, as the main component of cleaning agents, can effectively dissolve and remove silica scale;

[0070] Dispersants can disperse and suspend silica scale particles to prevent them from redepositing on the membrane surface;

[0071] Inorganic surfactants can reduce the surface tension of water and enhance the penetration and wetting properties of cleaning agents;

[0072] Corrosion inhibitors can slow down the corrosion of cleaning agents on membrane elements and extend the service life of the membrane;

[0073] The multivalent sequestrant can combine with the metal ions in the silica scale to form a stable chelate, thus helping to remove the silica scale;

[0074] Defoaming agent can eliminate the foam generated by the cleaning agent during the cleaning process and improve the cleaning efficiency;

[0075] Stabilizers can maintain the stability of cleaning agents and prevent them from decomposing or deteriorating during storage and use;

[0076] PH regulator can adjust the pH of the cleaning agent to adapt it to the cleaning needs of different membrane elements;

[0077] Deionized water can dissolve and dilute the above ingredients to form a uniform cleaning solution.

[0078] Experimental design

[0079] Experimental Materials:

[0080] The contaminated DTRO (disc-tube reverse osmosis) membrane column came from the leachate treatment system of a landfill project in Sichuan;

[0081] Cleaning agent: including the cleaning agent proposed in this application, conventional acid cleaning agent, conventional alkaline cleaning agent and commercially available silica scale cleaning agent;

[0082] Test equipment: Scanning electron microscope (SEM), clean water flux and retention rate test device;

[0083] Experimental steps:

[0084] Test before cleaning: Use SEM to perform point and line analysis on the membrane to determine the degree of silica scale contamination on the membrane surface, and record the clear water flux and retention rate before cleaning;

[0085] Cleaning agent preparation: according to the formula ratio of each cleaning agent, use deionized water to prepare the cleaning solution;

[0086] Cleaning operation: Use offline cleaning method to clean the membrane column according to the predetermined cleaning process (water washing, detergent cleaning, and water washing again);

[0087] Post-cleaning test: Use SEM to characterize and analyze the membrane again, and record the clean water flux and retention rate after cleaning;

[0088] Data analysis: Compare the SEM images of the membrane before and after cleaning with each cleaning agent, the changes in the clear water flux and the retention rate, and evaluate the cleaning effect;

[0089] Experimental Results

[0090] SEM characterization: After cleaning, the silicon scale on the membrane surface using the cleaning agent of the present application is significantly reduced, and the membrane surface is smoother, indicating that the cleaning agent can effectively remove silicon scale;

[0091] Clear water flux: The clear water flux of the cleaning agent of the present application after cleaning is significantly higher than that of conventional cleaning agents and commercially available silica scale cleaning agents, indicating that it has a stronger ability to restore membrane filtration performance;

[0092] Retention rate: After cleaning, the retention rate of each cleaning agent changed, but the retention rate of the cleaning agent in this application remained stable or slightly increased, indicating that the cleaning agent did not damage the membrane element while removing silica scale.

[0093] in conclusion

[0094] Through this cleaning experiment, we verified the beneficial effects of the reverse osmosis membrane silicon scale cleaning agent formula proposed in this application:

[0095] The cleaning agent of the present application can significantly remove the silica scale on the membrane surface and restore the filtration performance and water permeability of the membrane.

[0096] The cleaning agent removes silica scale without causing significant damage to the membrane element, thus maintaining the membrane retention rate.

[0097] The ingredients in the cleaning agent are all environmentally friendly chemicals, which will not pollute the environment or cause harm to the human body;

[0098] The cleaning agent exhibits good stability during storage and use and is suitable for cleaning silica scale on various reverse osmosis membranes.

[0099] Although the embodiments of the present invention have been shown and described, as detailed above, it will be understood by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. The formula of reverse osmosis membrane silicon scale cleaning agent is characterized by: The invention comprises an inorganic acid cleaning agent, a dispersant, an inorganic surfactant, a corrosion inhibitor, a multivalent chelating agent, a defoaming agent, a stabilizer and a pH regulator, and the components thereof are calculated by mass percentage as follows: 10-25% of an inorganic acid cleaning agent, 1-5% of a dispersant, 2-8% of an inorganic surfactant, 0.1-0.5% of a corrosion inhibitor, 3-10% of a multivalent chelating agent, 0.1-0.3% of a defoaming agent, 0.1-0.3% of a stabilizer, 0.1-0.5% of a pH regulator and the balance is deionized water.

2. The reverse osmosis membrane silicon scale cleaning agent formulation according to claim 1, characterized in that: The inorganic acid cleaning agent is sulfuric acid.

3. The reverse osmosis membrane silicon scale cleaning agent formulation according to claim 1, characterized in that: The inorganic surfactant is sodium tripolyphosphate.

4. The reverse osmosis membrane silicon scale cleaning agent formulation according to claim 1, characterized in that: The multivalent sequestrant is tetrasodium glutamate diacetate.

5. The reverse osmosis membrane silicon scale cleaning agent formulation according to claim 1, characterized in that: The dispersant is one or a combination of polyacrylic acid and polycarboxylate.

6. The reverse osmosis membrane silicon scale cleaning agent formulation according to claim 1, characterized in that: The corrosion inhibitor is one of nitrite, silicate and benzotriazole.

7. The reverse osmosis membrane silicon scale cleaning agent formulation according to claim 1, characterized in that: The defoaming agent is one of silicone oil and polyether.

8. The reverse osmosis membrane silicon scale cleaning agent formulation according to claim 1, characterized in that: The stabilizer is one of sodium nitrite and sodium sulfite.

9. The reverse osmosis membrane silicon scale cleaning agent formulation according to claim 1, characterized in that: The pH regulator is one of ammonia water and sodium hydroxide.

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