An anti-scaling agent for reverse osmosis membranes used in sewage treatment and its application

Abstract

The present invention provides an anti-scaling agent for reverse osmosis membranes used in sewage treatment and its application. The anti-scaling agent for reverse osmosis membranes comprises the following components in parts by mass: 15-25 parts by mass of a scale inhibitor, 15-20 parts by mass of sodium hydroxide, 0.5-5 parts of polyhydroxystearic acid, and 50-65 parts by mass of water. Compared with the prior art anti-scaling agents, the anti-scaling agent provided by the present invention can increase the limit of preventing the deposition of inorganic salts such as calcium carbonate during the reverse osmosis treatment of sewage. When treating sewage, it can significantly improve the anti-scaling ability of the anti-scaling agent against inorganic salts such as calcium carbonate, thereby improving the treatment effect of the reverse osmosis membrane on sewage.

Description

Technical Field

[0001] The present invention belongs to the technical field of scale inhibitor production, and particularly relates to a reverse osmosis membrane scale inhibitor for sewage treatment, its application and its preparation method. Background Art

[0002] With the increasing shortage of water resources and the continuous deterioration of water quality environment, if domestic sewage and industrial sewage are directly discharged, it will not only further pollute the water quality but also cause damage to the environment. Therefore, various sewage needs to be treated before discharge.

[0003] Reverse osmosis, also known as reverse osmosis, is a membrane separation operation that separates solvents from solutions with a pressure difference as the driving force. Since the reverse osmosis membrane in the reverse osmosis equipment can intercept various inorganic ions, colloidal substances and macromolecular solutes in water to obtain purified water, and the reverse osmosis process is simple and has low energy consumption, it is widely used in the desalination of seawater and brackish water; water softening treatment; wastewater treatment; and purification, concentration, separation, etc. in the food, pharmaceutical, and chemical industries.

[0004] However, when the reverse osmosis equipment effectively removes various inorganic ions, colloidal substances, macromolecular solutes, etc. in domestic sewage and industrial sewage, inorganic salts will scale on the surface of the reverse osmosis membrane. The scaling on the surface of the reverse osmosis membrane will seriously affect the normal and stable operation of the system, deteriorate the effluent water quality, shorten the service life of the reverse osmosis membrane, and increase the production cost of enterprises. And scale inhibitors are the most direct and effective method to prevent the reverse osmosis equipment from scaling.

[0005] Scale inhibitors have the function of dispersing insoluble inorganic salts in water and preventing or interfering with the precipitation and scaling of insoluble inorganic salts on the metal surface. However, when the scale inhibitor in the prior art is added to a certain concentration, it will reach the limit of the scale inhibitor to prevent and interfere with the deposition of insoluble inorganic salts. At this time, the scale inhibition ability will no longer increase, thereby reducing the scale inhibition effect of the scale inhibitor. Summary of the Invention

[0006] The purpose of the present invention is to provide a reverse osmosis membrane scale inhibitor for sewage treatment and its application, so as to solve the problem that when the scale inhibitor is added to a certain concentration, it will reach the limit of the scale inhibitor to prevent and interfere with the deposition of insoluble inorganic salts. At this time, the scale inhibition ability will no longer increase, thereby reducing the scale inhibition effect of the scale inhibitor as described in the above background art.

[0007] To achieve the above object, the present invention provides the following technical solution: An anti-scaling agent for reverse osmosis membranes used in sewage treatment, comprising the following components in parts by mass: 15-25 parts by mass of a scaling inhibitor, 15-20 parts by mass of sodium hydroxide, 0.5-5 parts of polyhydroxystearic acid, and 50-65 parts by mass of water. Among them, the mass fraction of the scaling inhibitor is 15-25 (including all values therebetween), for example, 15, 16, 17, 18, 20, 21, 23, 25 or the value range between any two of them. To improve the anti-scaling ability of the anti-scaling agent for reverse osmosis membranes, preferably, the scaling inhibitor is 16-23 parts by mass, and further preferably, the scaling inhibitor is 16-20 parts by mass; the mass fraction of sodium hydroxide is 15-20 (including all values therebetween), for example, 15, 16, 17, 18, 19, 20 or the value range between any two of them. Preferably, the mass fraction of sodium hydroxide is 16-18. The sodium hydroxide in the present invention is used to adjust the pH value of the scaling inhibitor; the mass fraction of polyhydroxystearic acid is 0.5-5 (including all values therebetween), for example, 0.5, 1, 1.5, 2, 2.5, 3, 4, 5 or the value range between any two of them. The selection of polyhydroxystearic acid can not only prevent the sedimentation and aggregation of calcium carbonate, calcium sulfate, magnesium carbonate, etc. in sewage, but also improve the limit of the anti-scaling agent to prevent the deposition of insoluble inorganic salts and improve the anti-scaling ability of the scaling inhibitor. Preferably, polyhydroxystearic acid is 0.5-2 parts; the mass fraction of water is 50-65 (including all values therebetween), for example, 50, 52, 55, 57, 60, 62, 65 or the value range between any two of them. Preferably, water is 55-65 parts by mass.

[0008] The polyhydroxystearic acid is at least one of dihydroxystearic acid and trihydroxystearic acid.

[0009] The dihydroxystearic acid is at least one of 9,12-dihydroxystearic acid, 9,10-dihydroxystearic acid, and 10,12-dihydroxystearic acid. For example, 9,10-dihydroxystearic acid can be prepared by the synthesis method of the journal named "Chemical Research and Application", and the paper is "Synthesis of Two Hydroxystearic Acids and Their Influence on the Performance of Lithium Grease". 9,12-dihydroxystearic acid and 10,12-dihydroxystearic acid are, for example, 9,12-dihydroxystearic acid and 10,12-dihydroxystearic acid produced by Guangzhou Fufei Chemical, a powerful supplier.

[0010] The trihydroxystearic acid is 9,10,12-trihydroxystearic acid. For example, 9,10,12-trihydroxystearic acid can also be prepared by the synthesis method of the journal named "Chemical Research and Application", and the paper is "Synthesis of Two Hydroxystearic Acids and Their Influence on the Performance of Lithium Grease".

[0011] The inhibitor is composed of polyepoxysuccinic acid, ethylenediaminetetraacetic acid, and polyaspartic acid in a mass ratio of 1:(0.5 - 1):(0.1 - 0.6). Polyepoxysuccinic acid is a nitrogen-free and phosphorus-free organic compound with little water pollution and has dual functions of scale inhibition and corrosion inhibition. Ethylenediaminetetraacetic acid is a chelating agent that can combine with divalent metal ions such as Mg 2+ , Ca 2+ , Mn 2+ , Fe 2+ etc., and has a scale inhibition effect. Moreover, ethylenediaminetetraacetic acid is weakly acidic and can react with carbonates to release carbon dioxide, thereby preventing, blocking, or interfering with the precipitation and scaling of sparingly soluble inorganic salts on the surface of reverse osmosis membranes, etc. And since ethylenediaminetetraacetic acid is weakly acidic, it will not corrode the metal surface and does not affect the service life of the reverse osmosis equipment. Polyaspartic acid is biodegradable and has no pollution to the environment. As a water treatment agent, polyaspartic acid not only has scale inhibition and corrosion inhibition effects but also has a dispersing effect. As a scale inhibitor, it is particularly suitable for inhibiting the formation of calcium carbonate scale, calcium sulfate scale, barium sulfate scale, and calcium phosphate scale in cooling water, boiler water, and reverse osmosis treatment, and can effectively prevent the corrosion of metal equipment, and is widely used. Polyepoxysuccinic acid is prepared, for example, by the synthesis method provided in the paper "Improvement of the Synthesis Method of Polyepoxysuccinic Acid and Measurement Method of Scale Inhibition Rate" published in the journal "Functional Materials". Ethylenediaminetetraacetic acid can be produced, for example, by Weifang Binhai Petrochemical Co., Ltd. with the authorization number CN113444006B and the patent name "A Production Method of Ethylenediaminetetraacetic Acid". Polyaspartic acid is prepared, for example, by Zhejiang Xinhe Environmental Technology Co., Ltd. with the authorization number CN102146161B and the patent name "A Preparation Method of a Polyaspartic Acid Composite for Scale Inhibitor". Polyepoxysuccinic acid has the effects of scale inhibition and corrosion inhibition. When polyepoxysuccinic acid is used alone, its corrosion inhibition effect is poor. When used in combination with ethylenediaminetetraacetic acid and polyaspartic acid, it has a better corrosion inhibition effect.

[0012] In some embodiments of the present invention, in order to further improve the limit of the scale inhibitor to prevent and interfere with the deposition of sparingly soluble inorganic salts and improve the scale inhibition ability of the scale inhibitor, when the mass ratio of polyepoxysuccinic acid:ethylenediaminetetraacetic acid:polyaspartic acid in the inhibitor remains between 1:(0.5 - 1):(0.1 - 0.6), the scale inhibitor provided by the present invention has a better effect on preventing inorganic salt scales such as calcium carbonate.

[0013] In some embodiments of the present invention, the scale inhibitor further comprises 0.1 - 2 parts by mass of an anionic surfactant, and the anionic surfactant is at least one of 2 - acrylamide - 2 - methylpropanesulfonic acid, polymethacrylic acid, sodium dodecylbenzenesulfonate, N - oleoyl N - methyltaurine sodium salt, sodium alkylbenzenesulfonate, and sodium alkyl sulfate. The parts by mass of the anionic surfactant is 0.1 - 2 (including all values therebetween), for example, 0.1, 0.3, 0.5, 0.8, 1, 1.2, 1.5, 1.8, 2, or the value range between any two of them. In order to further improve the scale inhibition and removal effect of the reverse osmosis device, a surfactant can also be selected, thereby further reducing the possibility of scale formation in the reverse osmosis device. Preferably, the anionic surfactant is 0.2 - 0.6 parts by mass.

[0014] In some embodiments of the present invention, the scale inhibitor further comprises 0.2 - 0.8 parts by mass of a corrosion inhibitor, and the corrosion inhibitor is at least one of triethanolamine, benzalkonium bromide, and propargyl alcohol amine. In order to prevent the reverse osmosis device from being corroded by substances in the sewage, a corrosion inhibitor is used. The use of the corrosion inhibitor can prevent or slow down the degree of corrosion of the reverse osmosis device, thereby better protecting the metal. The parts by mass of the corrosion inhibitor is 0.2 - 0.8 (including all values therebetween), for example, 0.2, 0.5, 0.6, 0.7, 0.8, or the value range between any two of them. Preferably, the corrosion inhibitor is 0.3 - 0.6 parts by mass.

[0015] In some embodiments of the present invention, the scale inhibitor further comprises 1 - 5 parts by mass of a coagulation inhibitor, and the coagulation inhibitor is hydroxybutanedioic acid. The parts by mass of the coagulation inhibitor is 1 - 5 (including all values therebetween), for example, 1, 1.5, 2, 2.5, 3, 3.5, 4, 4.5, 5, or the value range between any two of them. Preferably, the parts by mass of the coagulation inhibitor is 3 - 5. The coagulation inhibitor plays a role in preventing or inhibiting coagulation between mixtures, thereby making the substances in the scale inhibitor more evenly distributed.

[0016] In some embodiments of the present invention, the scale inhibitor further comprises 0.1 - 0.5 parts by mass of citric acid. The mass fraction of citric acid is 0.1 - 0.5 (including all values therebetween), for example, 0.1, 0.2, 0.3, 0.4, 0.5, or the value range between any two of them. Preferably, the mass fraction of citric acid is 0.2 - 0.4. Citric acid is a safe cleaning agent that can peel off the old scale in the water pipe, making the water pipe smooth and clean. Since citric acid does not contain Cl - , it has little corrosion to metals, so it will not cause corrosion to the equipment.

[0017] In some embodiments of the present invention, the method for preparing the reverse osmosis membrane scale inhibitor is as follows: Take the scale inhibitor, sodium hydroxide, polyhydroxystearic acid, water, anionic surfactant, corrosion inhibitor, coagulation inhibitor and citric acid in the required mass fractions of the formula for mixing. The mixing time is 1 - 2 h, the mixing speed is 50 - 120 r / min. After mixing evenly, the reverse osmosis membrane scale inhibitor is obtained.

[0018] On the other hand, the present invention also provides the application of the above-mentioned reverse osmosis membrane scale inhibitor for sewage treatment in sewage reverse osmosis equipment.

[0019] Compared with the prior art, the beneficial effects of the present invention are as follows: Compared with the scale inhibitors of the prior art, the scale inhibitor provided by the present invention can increase the limit of preventing the deposition of inorganic salts such as calcium carbonate. When treating sewage, it can significantly improve the scale inhibition ability of the scale inhibitor against inorganic salts such as calcium carbonate, thereby improving the treatment effect of the reverse osmosis membrane on sewage. Specific Embodiments

[0020] The following further clarifies the present invention in combination with specific embodiments. It should be understood that the following specific embodiments are only used to illustrate the present invention and not to limit the scope of the present invention.

[0021] A reverse osmosis membrane scale inhibitor for sewage treatment includes the following components in mass fractions: 15 - 25 mass parts of scale inhibitor, 15 - 20 mass parts of sodium hydroxide, 0.5 - 5 parts of polyhydroxystearic acid, 50 - 65 mass parts of water. Among them, the polyhydroxystearic acid is at least one of dihydroxystearic acid and trihydroxystearic acid. The dihydroxystearic acid is at least one of 9,12 - dihydroxystearic acid, 9,10 - dihydroxystearic acid, 10,12 - dihydroxystearic acid, and the trihydroxystearic acid is 9,10,12 - trihydroxystearic acid.

[0022] Among them, the scale inhibitor is composed of polyepoxysuccinic acid, ethylenediaminetetraacetic acid and polyaspartic acid in a mass ratio of 1:(0.5 - 1):(0.1 - 0.6).

[0023] Among them, the scale inhibitor further includes 0.1 - 2 mass parts of anionic surfactant. The anionic surfactant is at least one of 2 - acrylamide - 2 - methylpropanesulfonic acid, polymethacrylic acid, sodium dodecylbenzenesulfonate, N - oleoyl N - methyltaurine sodium salt, alkylbenzenesulfonate and sodium alkyl sulfate.

[0024] Among them, the scale inhibitor further includes 0.2 - 0.8 mass parts of corrosion inhibitor. The corrosion inhibitor is at least one of triethanolamine, benzalkonium bromide, propargyl alcohol amine.

[0025] Among them, the scale inhibitor further includes 1 - 5 mass parts of coagulation inhibitor and 0.1 - 0.5 mass parts of citric acid. The coagulation inhibitor is hydroxybutanedioic acid.

[0026] On the other hand, the present invention also provides the application of the reverse osmosis membrane scale inhibitor for sewage treatment in a sewage reverse osmosis device.

[0027] When preparing the reverse osmosis membrane scale inhibitor for sewage treatment based on the preparation method of the reverse osmosis membrane scale inhibitor for sewage treatment, the following production process is included:

[0028] Take the required mass parts of inhibitor, sodium hydroxide, polyhydroxystearic acid, water, anionic surfactant, corrosion inhibitor, coagulation inhibitor and citric acid for mixing. The mixing time is 1 - 2 h, the mixing speed is 50 - 120 r / min. After mixing evenly, the reverse osmosis membrane scale inhibitor is obtained.

[0029] The present invention will be further described below in conjunction with specific embodiments, but the protection scope of the present invention is not limited thereto.

[0030] Example 1: A reverse osmosis membrane scale inhibitor for sewage treatment, comprising the following components in mass parts: 10 parts by mass of polyepoxysuccinic acid, 5 parts by mass of ethylenediaminetetraacetic acid, 1.8 parts by mass of polyaspartic acid, 16.5 parts by mass of sodium hydroxide, 0.6 part of 9,12-dihydroxystearic acid, 62 parts by mass of water, 0.2 part of 2-acrylamide-2-methylpropanesulfonic acid, 0.4 part of triethanolamine, 3 parts by mass of hydroxybutanedioic acid and 0.3 part of citric acid.

[0031] Example 2: A reverse osmosis membrane scale inhibitor for sewage treatment, comprising the following components in mass parts: 10 parts by mass of polyepoxysuccinic acid, 5 parts by mass of ethylenediaminetetraacetic acid, 5 parts by mass of polyaspartic acid, 15 parts by mass of sodium hydroxide, 0.4 part of 9,12-dihydroxystearic acid, 0.3 part of 9,10-dihydroxystearic acid, 62 parts by mass of water, 0.5 part of polymethacrylic acid, 0.6 part of propargyl alcohol amine, 2 parts by mass of hydroxybutanedioic acid and 0.4 part of citric acid.

[0032] Example 3: A reverse osmosis membrane scale inhibitor for sewage treatment, comprising the following components in mass parts: 10 parts by mass of polyepoxysuccinic acid, 10 parts by mass of ethylenediaminetetraacetic acid, 5 parts by mass of polyaspartic acid, 18 parts by mass of sodium hydroxide, 5 parts by mass of 9,10,12-trihydroxystearic acid, 65 parts by mass of water, 1 part of N-oleoyl-N-methyltaurine sodium, 0.8 part of triethanolamine, 5 parts by mass of hydroxybutanedioic acid and 0.5 part of citric acid.

[0033] Example 4: Using the components of the reverse osmosis membrane scale inhibitor for sewage treatment and the mass parts of each component are basically the same as those in Example 1, the difference is: 12 parts by mass of polyepoxysuccinic acid, 2.4 parts by mass of ethylenediaminetetraacetic acid, 2.4 parts by mass of polyaspartic acid.

[0034] Example 5 (compared with Example 2): The scale inhibitor components for sewage treatment reverse osmosis membranes are used, and the mass parts of each component are basically the same as those in Example 1, except that: 10 parts by mass of polyepoxysuccinic acid, 1 part by mass of ethylenediaminetetraacetic acid, and 9 parts by mass of polyaspartic acid.

[0035] Example 6: The scale inhibitor components for sewage treatment reverse osmosis membranes are used, and the mass parts of each component are basically the same as those in Example 3, except that: 10 parts by mass of polyepoxysuccinic acid, 4 parts by mass of ethylenediaminetetraacetic acid, and 2.8 parts by mass of polyaspartic acid.

[0036] Example 7: The scale inhibitor components for sewage treatment reverse osmosis membranes are used, and the mass parts of each component are basically the same as those in Example 1, except that: 10 parts by mass of polyepoxysuccinic acid, 6 parts by mass of ethylenediaminetetraacetic acid, and 8 parts by mass of polyaspartic acid.

[0037] Comparative Example 1: The scale inhibitor components for sewage treatment reverse osmosis membranes are used, and the mass parts of each component are basically the same as those in Example 1, except that: polyhydroxystearic acid is not added.

[0038] Comparative Example 2: The scale inhibitor components for sewage treatment reverse osmosis membranes are used, and the mass parts of each component are basically the same as those in Example 1, except that: 9,12-dihydroxystearic acid is replaced with 12-hydroxystearic acid.

[0039] When preparing the reverse osmosis membrane scale inhibitors required for Examples 1 to 7, the following production process is used for all:

[0040] Take the mass parts of inhibitor, sodium hydroxide, polyhydroxystearic acid, water, anionic surfactant, corrosion inhibitor, anti-coagulant, and citric acid required by the formula for mixing. The mixing time is 1 h, the mixing speed is 100 r / min. After mixing evenly, the reverse osmosis membrane scale inhibitor is prepared.

[0041] When preparing the reverse osmosis membrane scale inhibitor required for Comparative Example 1, the following production process is used:

[0042] Take the mass parts of inhibitor, sodium hydroxide, water, anionic surfactant, corrosion inhibitor, anti-coagulant, and citric acid required by the formula for mixing. The mixing time is 1 h, the mixing speed is 100 r / min. After mixing evenly, the reverse osmosis membrane scale inhibitor is prepared.

[0043] When preparing the reverse osmosis membrane scale inhibitor required for Comparative Example 2, the following production process is used:

[0044] Take the mass parts of inhibitor, sodium hydroxide, 12-hydroxystearic acid, water, anionic surfactant, corrosion inhibitor, anti-coagulant, and citric acid required by the formula for mixing. The mixing time is 1 h, the mixing speed is 100 r / min. After mixing evenly, the reverse osmosis membrane scale inhibitor is prepared.

[0045] The performance test of the reverse osmosis membrane scale inhibitor includes the following methods:

[0046] A: Add CaCl2 solution with V1 (150 mL) and C1 (0.009 mol / L) into a container, and add a reverse osmosis scale inhibitor with a dosage of W (1 mg / L).

[0047] B: Keep the container in a closed state, at a constant temperature of (25 ± 1) °C, and with an electromagnetic stirring speed of (20 r / min). Dropwise add NaHCO3 solution with V2 (2 mL) and C2 (0.3 mol / L), and record it as the first time.

[0048] C: After 2 minutes, measure the pH value of the solution with a digital pH meter. At the same time, dropwise add NaHCO3 solution with V2 (2 ml) and C2 (0.3 mol / l) again, and record it as the second time.

[0049] D: Repeat step C for a total of n times. At this time, the pH value of the solution decreases (CaCO3 precipitate is formed in the solution). Record the pH value p of the solution after the (n - 1)-th dropwise addition of NaHCO3, and calculate the cumulative volume V of the NaHCO3 solution consumed in (n - 1) times, where V = (n - 1)V2.

[0050] E: Calculate the supersaturation S of CaCO3 in the solution before the precipitation is formed. Judge the scale inhibition performance of the scale inhibitor according to the size of S. The larger the S value, the better the scale inhibition effect of the scale inhibitor on carbonate scale.

[0051] According to the data recorded during the experiment, the calculation process is as follows:

[0052]

[0053]

[0054]

[0055]

[0056] In the formula: [Ca 2+ , [HCO3 - , [CO3 2- , [H + represent the concentrations of calcium ions, bicarbonate ions, carbonate ions, and hydrogen ions before the pH value decreases, with the unit of mol / L;

[0057] K2 represents the second ionization equilibrium constant of carbonic acid; at 25 °C, K2 = 10 -10.33 ;

[0058] K sp represents the solubility product constant of CaCO3; at 25 °C, K spis 4.8×10 -9 ;

[0059] V = (n - 1)V2;

[0060] [H + = 10 -p .

[0061] During the performance test of the reverse osmosis scale inhibitor, the reverse osmosis membrane scale inhibitors prepared in Examples 1 to 7, Comparative Example 1, and Comparative Example 2 were respectively added, and the supersaturation S value was tested and calculated;

[0062] At the same time, without adding the scale inhibitor as a blank test, the supersaturation S value of the blank test was tested and calculated. The test results are shown in Table 1:

[0063] Table 1

[0064]

[0065] As can be seen from Table 1, in the presence of the scale inhibitor, the formation of inorganic scale such as calcium carbonate in sewage can be prevented. When testing the performance of the reverse osmosis membrane scale inhibitor, without adding polyhydroxystearic acid, the measured supersaturation S value is only 767. However, when using the scale inhibitor prepared by the present invention, the measured supersaturation S value can reach above 836. It can be seen that compared with the prior art, the scale inhibitor provided by the present invention can improve the limit of preventing calcium carbonate scale deposition and continue to prevent the formation of calcium carbonate;

[0066] And when the monohydroxystearic acid selected is 12-hydroxystearic acid, the measured supersaturation S value is 817. Compared with Comparative Example 1, although the limit of preventing scale inhibitor deposition is improved, the achieved test effect is still not optimistic. However, when the scale inhibitor prepared by the present invention uses polyhydroxystearic acid, the measured supersaturation value can reach above 836. It can be seen that compared with using monohydroxystearic acid, when the scale inhibitor provided by the present invention adds polyhydroxystearic acid, the limit of the scale inhibitor preventing calcium carbonate scale deposition is significantly improved;

[0067] When the mass fraction of the scale inhibitor used is 15 - 25, when the mass ratio of ethylenediaminetetraacetic acid: polyaspartic acid in the scale inhibitor is not between 1:(0.5 - 1):(0.1 - 0.6), the supersaturation S value reaches at most 895, while when the mass ratio is between 1:(0.5 - 1):(0.1 - 0.6), the supersaturation S value is above 955. It can be seen that when the mass ratio of polyepoxysuccinic acid: ethylenediaminetetraacetic acid: polyaspartic acid in the scale inhibitor of the present invention is 1:(0.5 - 1):(0.1 - 0.6), the limit of the scale inhibitor preventing calcium carbonate scale deposition can be further improved.

[0068] In summary, compared with the scale inhibitors in the prior art, the scale inhibitor provided by the present invention can increase the limit of preventing the deposition of inorganic salts such as calcium carbonate. When treating sewage, it can significantly improve the scale inhibition ability of the scale inhibitor against calcium carbonate scale, thereby improving the treatment effect of the reverse osmosis membrane on sewage.

[0069] It should be noted that in this text, relational terms such as first and second are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any actual relationship or order between these entities or operations. Moreover, the term "comprising", "including" or any other variant thereof is intended to cover non-exclusive inclusion, so that a process, method, article or device comprising a series of elements not only includes those elements, but also includes other elements not expressly listed, or also includes elements inherent to such process, method, article or device.

[0070] Although the embodiments of the present invention have been shown and described, for those of ordinary skill in the art, it can be understood that various changes, modifications, substitutions and variations can be made to these embodiments without departing from the principles and spirit of the present invention. The scope of the present invention is defined by the appended claims and their equivalents. Obviously, the embodiments described in the present invention are only a part of the embodiments of the present invention, rather than all embodiments. Based on the embodiments in the present invention, all other embodiments obtained by those of ordinary skill in the art without creative work fall within the scope of protection of the present invention.

Claims

1. An antiscalant for reverse osmosis membranes used in sewage treatment, characterized in that: Comprising the following components in parts by mass: 15 - 25 parts by mass of a scale inhibitor, 15 - 20 parts by mass of sodium hydroxide, 0.5 - 5 parts of polyhydroxystearic acid, and 50 - 65 parts by mass of water; The polyhydroxystearic acid is at least one of dihydroxystearic acid and trihydroxystearic acid; The scale inhibitor is composed of polyepoxysuccinic acid, ethylenediaminetetraacetic acid, and polyaspartic acid in a mass ratio of 1:(0.5 - 1):(0.1 - 0.6).

2. The scale inhibitor for reverse osmosis membrane used in sewage treatment according to claim 1, characterized in that: The dihydroxystearic acid is at least one of 9,12 - dihydroxystearic acid, 9,10 - dihydroxystearic acid, and 10,12 - dihydroxystearic acid.

3. The antiscalant for reverse osmosis membrane used in sewage treatment according to claim 1, characterized in that: The trihydroxystearic acid is 9,10,12 - trihydroxystearic acid.

4. A scale inhibitor for reverse osmosis membranes used in sewage treatment according to claim 1, characterized in that: It further comprises 0.1 - 2 parts by mass of an anionic surfactant, and the anionic surfactant is at least one of 2 - acrylamide - 2 - methylpropanesulfonic acid, polymethacrylic acid, sodium dodecylbenzenesulfonate, sodium N - oleoyl - N - methyltaurate, alkylbenzenesulfonate, and sodium alkyl sulfate.

5. A scale inhibitor for reverse osmosis membranes used in sewage treatment according to claim 1, characterized in that: It further comprises 0.2 - 0.8 parts by mass of a corrosion inhibitor, and the corrosion inhibitor is at least one of triethanolamine, benzalkonium bromide, and propargyl alcoholamine.

6. The antiscalant for reverse osmosis membrane used in sewage treatment according to claim 1, wherein: It further comprises 1 - 5 parts by mass of a setting retarder, and the setting retarder is hydroxybutanedioic acid.

7. The scale inhibitor for reverse osmosis membrane used in sewage treatment according to claim 1, characterized in that: It further comprises 0.1 - 0.5 parts by mass of citric acid.

8. Use of the reverse osmosis membrane scale inhibitor for sewage treatment according to any one of claims 1 - 7 in a sewage reverse osmosis device.

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