Environmentally friendly reverse osmosis scale inhibitor and preparation method thereof

Abstract

This invention discloses an environmentally friendly reverse osmosis antiscalant and its preparation method. The environmentally friendly reverse osmosis antiscalant is made from the following raw materials in parts by weight: 30-50 parts of butenoic acid-acrylamide-hydroxypropyl acrylate copolymer, 20-30 parts of methyl sulfonate polyepoxysuccinic acid, 10-20 parts of maleic acid-acrylic acid copolymer, 5-15 parts of sodium polyepoxysuccinate, 5-15 parts of sodium polyaspartate, and 5-10 parts of fatty alcohol polyoxyethylene ether. The butenoic acid-acrylamide-hydroxypropyl acrylate copolymer is obtained by polymerizing butenoic acid, acrylamide, and hydroxypropyl acrylate monomers in a weight ratio of 8-15:5-10:3-12. The process includes the following steps: S1, adding isopropanol to water at 65-85°C to obtain a reaction system; S2, adding mixed monomers and initiators dropwise to the reaction system; S3, after the mixed monomers and initiators have been added, heating the system to 90-110°C and maintaining the temperature for 3-5 hours to obtain a butenoic acid-acrylamide-hydroxypropyl acrylate copolymer.

Description

Technical Field

[0001] The invention relates to the technical field of scale inhibitors, and in particular to an environmentally friendly reverse osmosis scale inhibitor and a preparation method thereof. Background Art

[0002] Reverse osmosis technology uses reverse osmosis membranes to separate water from ions in water, thereby achieving the purpose of purifying water. During the separation process, as water continuously passes through the reverse osmosis membrane, the salt in the water is enriched on the water inlet side of the membrane to form concentrated water. When the slightly soluble salt in the concentrated water exceeds its solubility product, it precipitates and causes scale to form, thereby clogging the reverse osmosis membrane. Therefore, in order to prevent the reverse osmosis membrane from being blocked by scale enriched by salt in the water, it is generally taken to add an appropriate amount of scale inhibitor (or reverse osmosis membrane protective agent) at the water inlet of the reverse osmosis system to protect the reverse osmosis membrane.

[0003] Reverse osmosis scale inhibitor is a scale inhibitor specially used in reverse osmosis system and nanofiltration and ultrafiltration system. It can prevent scaling on the membrane surface, improve water production and quality, and reduce operating costs. With the advancement of membrane science and technology, reverse osmosis water treatment technology has been widely used in the power, food, electronics, and chemical industries, and has been widely used in the fields of industrial water supply and sewage reuse deep treatment. The reverse osmosis membrane is a key equipment of the reverse osmosis system. When the system is running continuously for a long time, calcium and magnesium ions in the water will continue to precipitate and adhere to the surface of the reverse osmosis membrane, forming scale and breeding bacteria and algae, blocking the membrane pores, affecting the water output efficiency of the reverse osmosis system, damaging the reverse osmosis membrane, and causing energy waste. Therefore, preventing membrane scaling and bacterial and algae breeding plays a vital role in reverse osmosis operation. At present, the main reverse osmosis scale inhibitors have uneven product performance, low scale inhibition performance, and single function. Patent CN102010078A provides a reverse osmosis scale inhibitor that integrates antibacterial, corrosion inhibition and scale inhibition properties. However, due to the phosphorus content in the formula, it is easy to cause secondary pollution to the water body and does not meet the green environmental protection requirements. Therefore, research and development of a multifunctional environmentally friendly reverse osmosis scale inhibitor has a wide range of application value.

[0004] The weight percentage of each component of the reverse osmosis membrane scale inhibitor disclosed in Chinese patent CN101352655 is: 25-50% organic phosphonic acid, 20-40% sulfonate copolymer, 5-15% pH value regulator, and the rest is deionized water. The scale inhibitor can effectively control silicon scale and calcium scale. The weight percentage of each component of the reverse osmosis membrane scale inhibitor invented by Chinese patent CN1864826 is: 5-20% organic phosphonic acid compound, 0.5-1% lignin, 0.5-3% polymaleic acid or anhydride, 5-20% phosphine carboxylic acid, and the rest is water. The weight percentage of each component of the composite scale inhibitor disclosed in Chinese patent publication number CN1837101A is: 28-38% 2-phosphonic acid butane-1,2,4 tricarboxylic acid, 10-15% acrylic acid-acrylate-sulfonate copolymer, 10-15% zinc chloride, 1-2% benzotriazole, and the rest is water. Chinese patent CN102838215A discloses a composite scale inhibitor composed of polyepoxysuccinic acid, ethylenediaminetetramethylenephosphonic acid, itaconic acid-maleic acid-acrylic acid-methyl acrylate polymer and dendritic polyamide-amine. The weight percentage of each component of the scale inhibitor is: polyepoxysuccinic acid 22-32%, ethylenediaminetetramethylenephosphonic acid 10-18%, itaconic acid-maleic acid-acrylic acid-methyl acrylate polymer 35-50%, dendritic polyamide-amine 10-18%, and the rest is water.

[0005] Practice has shown that these traditional organic phosphine scale inhibitors and anionic polymer scale inhibitors and dispersants cannot simultaneously play a good scale inhibition effect on amorphous SiO2 scale precipitation, calcium carbonate scale, calcium sulfate scale, etc. In addition, these traditional organic phosphine scale inhibitors contain phosphorus and are not environmentally friendly.

[0006] Therefore, in view of this, the inventor, based on his many years of rich experience in design, development and actual production in the relevant industry, has conducted research and improvements on the existing technology and its deficiencies, and provided an environmentally friendly reverse osmosis antiscalant and a preparation method thereof, in order to achieve a more practical purpose. Summary of the invention

[0007] In order to solve the problems mentioned in the above background technology, the present invention provides an environmentally friendly reverse osmosis antiscalant and a preparation method thereof.

[0008] In order to achieve the above object, the present invention adopts the following technical solutions:

[0009] An environmentally friendly reverse osmosis antiscalant, the environmentally friendly reverse osmosis antiscalant is made of the following raw materials in parts by weight:

[0010] 30-50 parts of crotonic acid-acrylamide-hydroxypropyl acrylate copolymer, 20-30 parts of sulfonic acid methylamino polyepoxysuccinic acid, 10-20 parts of maleic acid-acrylic acid copolymer, 5-15 parts of sodium polyepoxysuccinate, 5-15 parts of sodium polyaspartate, and 5-10 parts of fatty alcohol polyoxyethylene ether.

[0011] Sulfonic acid methylamino polyepoxysuccinic acid (SMA / PESA) is an excellent multifunctional phosphorus-free scale inhibitor. Compared with PESA, its scale inhibition performance is significantly improved and it has a good complex synergistic effect. Its structure contains multiple hydrophilic groups such as carboxyl, ether, amine, hydroxyl, and sulfonic acid groups. It can not only effectively improve the solubility of the compound, but also form coordination compounds on the metal surface to undergo chemical adsorption, thereby enhancing its scale inhibition performance. The synergistic effect of multiple functional groups greatly improves its scale inhibition performance.

[0012] Preferably, the crotonic acid-acrylamide-hydroxypropyl acrylate copolymer is obtained by polymerizing three monomers of crotonic acid, acrylamide and hydroxypropyl acrylate, and the weight ratio of the three monomers is 8-15:5-10:3-12.

[0013] Preferably, the preparation method of the butenoic acid-acrylamide-hydroxypropyl acrylate copolymer comprises the following steps:

[0014] S1. adding isopropanol to water at 65-85° C. to obtain a reaction system;

[0015] S2, adding the mixed monomer and initiator dropwise to the reaction system;

[0016] S3. After the mixed monomers and initiator are added dropwise, the system is heated to 90-110° C. and kept warm for reaction for 3-5 hours to obtain a butenoic acid-acrylamide-hydroxypropyl acrylate copolymer.

[0017] Preferably, the initiator is persulfate, and the amount of the initiator is 0.5%-1.5% of the total weight of the mixed monomers.

[0018] Preferably, the persulfate is ammonium persulfate or potassium persulfate.

[0019] Preferably, the solid content of the sodium polyepoxysuccinate is 40%, and the solid content of the sodium polyaspartate is 40%.

[0020] Preferably, the solid content of the maleic acid-acrylic acid copolymer is 45-55 wt %, and the free monomer content calculated as maleic acid is ≤ 9.0 wt %.

[0021] A method for preparing an environmentally friendly reverse osmosis antiscalant further comprises the following steps:

[0022] S1, mixing crotonic acid-acrylamide-hydroxypropyl acrylate copolymer, sulfonic acid methylamino polyepoxysuccinic acid, and maleic acid-acrylic acid copolymer in a mass ratio of 1.2:1.1-1.5:2.1-2.5;

[0023] S2, heat the mixture obtained in S1 to 75-90°C, add fatty alcohol polyoxyethylene ether dropwise at a uniform rate within 2-3 hours, and perform ultrasonic treatment for 30-50 minutes.

[0024] S3, then raise the temperature to 95-100°C, add sodium polyepoxysuccinate and sodium polyaspartate, reflux for 2-2.5h, then cool the material to 60-65°C, and cool the filtrate to room temperature, which is an environmentally friendly reverse osmosis scale inhibitor.

[0025] Fatty alcohol polyoxyethylene ether (AEO) is a non-ionic surfactant. The ether bond in the molecule is not easily destroyed by acid or alkali, has high stability, good water solubility, electrolyte resistance, easy biodegradation, good compatibility, and is insensitive to hard water. However, its solubility will gradually decrease with the increase of water temperature. Within the pH range of 3-11, fatty alcohol polyoxyethylene ether is stable to hydrolysis.

[0026] Maleic acid-acrylic acid copolymer (MA / AA) has a strong dispersing effect on carbonates, etc., has high thermal stability, and can be used under harsh conditions such as high temperature of 300°C. It has good compatibility and synergistic effect with other water treatment agents, and has a good inhibitory effect on the formation of scale including phosphates, and has excellent scale inhibition and high temperature resistance.

[0027] Compared with the prior art, the present invention has the following beneficial effects:

[0028] 1. In the reverse osmosis scale inhibitor of the present invention, butylene acid-acrylamide-hydroxypropyl acrylate copolymer and sulfonic acid methylamino polyepoxysuccinic acid are the main components of the scale inhibitor, maleic acid-acrylic acid copolymer is an auxiliary scale inhibitor, and sodium polyepoxysuccinate, sodium polyaspartate and fatty alcohol polyoxyethylene ether are added to prepare a green, environmentally friendly and phosphorus-free reverse osmosis scale inhibitor.

[0029] 2. Among them, sulfonic acid methylamino polyepoxysuccinic acid, butylene acid-acrylamide-hydroxypropyl acrylate copolymer and maleic acid-acrylic acid copolymer have excellent corrosion and scale inhibition effects. After the three are compounded, the synergistic effect is obvious, and they have good degradability, no pollution to the environment, and have good adsorption properties, which can eliminate trace pollutants. After the above ingredients are compounded with the surfactant fatty alcohol polyoxyethylene ether, the water solubility and stability are enhanced, and long-term storage can be achieved, and the capacity-enhancing effect on pollutants, especially heavy metals, is obvious.

[0030] 3. The synergistic effect of various functional groups contained in each component of the present invention can effectively improve the solubility of the compound, achieve trace elimination of pollutants, and greatly improve its scale inhibition performance after compounding. It can effectively achieve the synergistic effect of physical adsorption and chemical adsorption of pollutants, can be used in a wider water supply pH range and temperature, and also has excellent sterilization effect.

[0031] 4. The production process of the present invention is simple, no "three wastes" are discharged, stability and water solubility are good, the main components are biodegradable, non-toxic, phosphorus-free, pollution-free, non-corrosive, the dosage is small, and it is environmentally friendly. DETAILED DESCRIPTION

[0032] The technical solution of the present invention will be clearly and completely described below in conjunction with the embodiments of the present invention. Obviously, the described embodiments are 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.

[0033] Example 1

[0034] An environmentally friendly reverse osmosis antiscalant, the environmentally friendly reverse osmosis antiscalant is made of the following raw materials in parts by weight:

[0035] 30 parts of crotonic acid-acrylamide-hydroxypropyl acrylate copolymer, 20 parts of sulfonic acid methylamino polyepoxysuccinic acid, 10 parts of maleic acid-acrylic acid copolymer, 5 parts of sodium polyepoxysuccinate, 5 parts of sodium polyaspartate, and 5 parts of fatty alcohol polyoxyethylene ether.

[0036] The crotonic acid-acrylamide-hydroxypropyl acrylate copolymer is obtained by polymerizing three monomers of crotonic acid, acrylamide and hydroxypropyl acrylate, and the weight ratio of the three monomers is 8:5:3.

[0037] The preparation method of the butenoic acid-acrylamide-hydroxypropyl acrylate copolymer comprises the following steps:

[0038] S1. adding isopropanol to water at 65-85° C. to obtain a reaction system;

[0039] S2, adding the mixed monomer and initiator dropwise to the reaction system;

[0040] S3. After the mixed monomers and initiator are added dropwise, the system is heated to 90-110° C. and kept warm for reaction for 3-5 hours to obtain a butenoic acid-acrylamide-hydroxypropyl acrylate copolymer.

[0041] The initiator is persulfate, and the amount of the initiator is 0.5% of the total weight of the mixed monomers.

[0042] The persulfate is ammonium persulfate.

[0043] The solid content of the sodium polyepoxysuccinate is 40%, and the solid content of the sodium polyaspartate is 40%.

[0044] The solid content of the maleic acid-acrylic acid copolymer is 45 wt %, and the free monomer content calculated as maleic acid is ≤ 9.0 wt %.

[0045] A method for preparing an environmentally friendly reverse osmosis antiscalant further comprises the following steps:

[0046] S1, mixing crotonic acid-acrylamide-hydroxypropyl acrylate copolymer, sulfonic acid methylamino polyepoxysuccinic acid, and maleic acid-acrylic acid copolymer in a mass ratio of 1.2:1.1:2.1;

[0047] S2, heat the mixture obtained in S1 to 75-90°C, add fatty alcohol polyoxyethylene ether dropwise at a uniform rate within 2-3 hours, and perform ultrasonic treatment for 30-50 minutes.

[0048] S3, then raise the temperature to 95-100°C, add sodium polyepoxysuccinate and sodium polyaspartate, reflux for 2-2.5h, then cool the material to 60-65°C, and cool the filtrate to room temperature, which is an environmentally friendly reverse osmosis scale inhibitor.

[0049] Example 2

[0050] An environmentally friendly reverse osmosis antiscalant, the environmentally friendly reverse osmosis antiscalant is made of the following raw materials in parts by weight:

[0051] 35 parts of crotonic acid-acrylamide-hydroxypropyl acrylate copolymer, 22 parts of sulfonic acid methylamino polyepoxysuccinic acid, 12 parts of maleic acid-acrylic acid copolymer, 8 parts of sodium polyepoxysuccinate, 7 parts of sodium polyaspartate, and 6 parts of fatty alcohol polyoxyethylene ether.

[0052] The crotonic acid-acrylamide-hydroxypropyl acrylate copolymer is obtained by polymerizing three monomers of crotonic acid, acrylamide and hydroxypropyl acrylate, and the weight ratio of the three monomers is 10:7:5.

[0053] The preparation method of the butenoic acid-acrylamide-hydroxypropyl acrylate copolymer comprises the following steps:

[0054] S1. adding isopropanol to water at 65-85° C. to obtain a reaction system;

[0055] S2, adding the mixed monomer and initiator dropwise to the reaction system;

[0056] S3. After the mixed monomers and initiator are added dropwise, the system is heated to 90-110° C. and kept warm for reaction for 3-5 hours to obtain a butenoic acid-acrylamide-hydroxypropyl acrylate copolymer.

[0057] The initiator is persulfate, and the amount of the initiator is 1% of the total weight of the mixed monomers.

[0058] The persulfate is potassium persulfate.

[0059] The solid content of the sodium polyepoxysuccinate is 40%, and the solid content of the sodium polyaspartate is 40%.

[0060] The solid content of the maleic acid-acrylic acid copolymer is 48 wt %, and the free monomer content calculated as maleic acid is ≤ 9.0 wt %.

[0061] A method for preparing an environmentally friendly reverse osmosis antiscalant further comprises the following steps:

[0062] S1, mixing crotonic acid-acrylamide-hydroxypropyl acrylate copolymer, sulfonic acid methylamino polyepoxysuccinic acid, and maleic acid-acrylic acid copolymer in a mass ratio of 1.2:1.2:2.2;

[0063] S2, heat the mixture obtained in S1 to 75-90°C, add fatty alcohol polyoxyethylene ether dropwise at a uniform rate within 2-3 hours, and perform ultrasonic treatment for 30-50 minutes.

[0064] S3, then raise the temperature to 95-100°C, add sodium polyepoxysuccinate and sodium polyaspartate, reflux for 2-2.5h, then cool the material to 60-65°C, and cool the filtrate to room temperature, which is an environmentally friendly reverse osmosis scale inhibitor.

[0065] Example 3

[0066] An environmentally friendly reverse osmosis antiscalant, the environmentally friendly reverse osmosis antiscalant is made of the following raw materials in parts by weight:

[0067] 40 parts of crotonic acid-acrylamide-hydroxypropyl acrylate copolymer, 25 parts of sulfonic acid methylamino polyepoxysuccinic acid, 15 parts of maleic acid-acrylic acid copolymer, 10 parts of sodium polyepoxysuccinate, 10 parts of sodium polyaspartate, and 8 parts of fatty alcohol polyoxyethylene ether.

[0068] The crotonic acid-acrylamide-hydroxypropyl acrylate copolymer is obtained by polymerizing three monomers of crotonic acid, acrylamide and hydroxypropyl acrylate, and the weight ratio of the three monomers is 11:7:8.

[0069] The preparation method of the butenoic acid-acrylamide-hydroxypropyl acrylate copolymer comprises the following steps:

[0070] S1. adding isopropanol to water at 65-85° C. to obtain a reaction system;

[0071] S2, adding the mixed monomer and initiator dropwise to the reaction system;

[0072] S3. After the mixed monomers and initiator are added dropwise, the system is heated to 90-110° C. and kept warm for reaction for 3-5 hours to obtain a butenoic acid-acrylamide-hydroxypropyl acrylate copolymer.

[0073] The initiator is persulfate, and the amount of the initiator is 1% of the total weight of the mixed monomers.

[0074] The persulfate is ammonium persulfate or potassium persulfate.

[0075] The solid content of the sodium polyepoxysuccinate is 40%, and the solid content of the sodium polyaspartate is 40%.

[0076] The solid content of the maleic acid-acrylic acid copolymer is 50 wt %, and the free monomer content calculated as maleic acid is ≤ 9.0 wt %.

[0077] A method for preparing an environmentally friendly reverse osmosis antiscalant further comprises the following steps:

[0078] S1, mixing crotonic acid-acrylamide-hydroxypropyl acrylate copolymer, sulfonic acid methylamino polyepoxysuccinic acid, and maleic acid-acrylic acid copolymer in a mass ratio of 1.2:1.3:2.3;

[0079] S2, heat the mixture obtained in S1 to 75-90°C, add fatty alcohol polyoxyethylene ether dropwise at a uniform rate within 2-3 hours, and perform ultrasonic treatment for 30-50 minutes.

[0080] S3, then raise the temperature to 95-100°C, add sodium polyepoxysuccinate and sodium polyaspartate, reflux for 2-2.5h, then cool the material to 60-65°C, and cool the filtrate to room temperature, which is an environmentally friendly reverse osmosis scale inhibitor.

[0081] Example 4

[0082] An environmentally friendly reverse osmosis antiscalant, the environmentally friendly reverse osmosis antiscalant is made of the following raw materials in parts by weight:

[0083] 45 parts of crotonic acid-acrylamide-hydroxypropyl acrylate copolymer, 28 parts of sulfonic acid methylamino polyepoxysuccinic acid, 18 parts of maleic acid-acrylic acid copolymer, 12 parts of sodium polyepoxysuccinate, 12 parts of sodium polyaspartate, and 9 parts of fatty alcohol polyoxyethylene ether.

[0084] The crotonic acid-acrylamide-hydroxypropyl acrylate copolymer is obtained by polymerizing three monomers of crotonic acid, acrylamide and hydroxypropyl acrylate, and the weight ratio of the three monomers is 13:9:10.

[0085] The preparation method of the butenoic acid-acrylamide-hydroxypropyl acrylate copolymer comprises the following steps:

[0086] S1. adding isopropanol to water at 65-85° C. to obtain a reaction system;

[0087] S2, adding the mixed monomer and initiator dropwise to the reaction system;

[0088] S3. After the mixed monomers and initiator are added dropwise, the system is heated to 90-110° C. and kept warm for reaction for 3-5 hours to obtain a butenoic acid-acrylamide-hydroxypropyl acrylate copolymer.

[0089] The initiator is persulfate, and the amount of the initiator used is 1.4% of the total weight of the mixed monomers.

[0090] The persulfate is potassium persulfate.

[0091] The solid content of the sodium polyepoxysuccinate is 40%, and the solid content of the sodium polyaspartate is 40%.

[0092] The solid content of the maleic acid-acrylic acid copolymer is 53 wt %, and the free monomer content calculated as maleic acid is ≤ 9.0 wt %.

[0093] A method for preparing an environmentally friendly reverse osmosis antiscalant further comprises the following steps:

[0094] S1, mixing crotonic acid-acrylamide-hydroxypropyl acrylate copolymer, sulfonic acid methylamino polyepoxysuccinic acid, and maleic acid-acrylic acid copolymer in a mass ratio of 1.2:1.4:2.4;

[0095] S2, heat the mixture obtained in S1 to 75-90°C, add fatty alcohol polyoxyethylene ether dropwise at a uniform rate within 2-3 hours, and perform ultrasonic treatment for 30-50 minutes.

[0096] S3, then raise the temperature to 95-100°C, add sodium polyepoxysuccinate and sodium polyaspartate, reflux for 2-2.5h, then cool the material to 60-65°C, and cool the filtrate to room temperature, which is an environmentally friendly reverse osmosis scale inhibitor.

[0097] Example 5

[0098] An environmentally friendly reverse osmosis antiscalant, the environmentally friendly reverse osmosis antiscalant is made of the following raw materials in parts by weight:

[0099] 50 parts of crotonic acid-acrylamide-hydroxypropyl acrylate copolymer, 30 parts of sulfonic acid methylamino polyepoxysuccinic acid, 20 parts of maleic acid-acrylic acid copolymer, 15 parts of sodium polyepoxysuccinate, 15 parts of sodium polyaspartate, and 10 parts of fatty alcohol polyoxyethylene ether.

[0100] The crotonic acid-acrylamide-hydroxypropyl acrylate copolymer is obtained by polymerizing three monomers of crotonic acid, acrylamide and hydroxypropyl acrylate, and the weight ratio of the three monomers is 15:10:12.

[0101] The preparation method of the butenoic acid-acrylamide-hydroxypropyl acrylate copolymer comprises the following steps:

[0102] S1. adding isopropanol to water at 65-85° C. to obtain a reaction system;

[0103] S2, adding the mixed monomer and initiator dropwise to the reaction system;

[0104] S3. After the mixed monomers and initiator are added dropwise, the system is heated to 90-110° C. and kept warm for reaction for 3-5 hours to obtain a butenoic acid-acrylamide-hydroxypropyl acrylate copolymer.

[0105] The initiator is persulfate, and the amount of the initiator is 1.5% of the total weight of the mixed monomers.

[0106] The persulfate is ammonium persulfate.

[0107] The solid content of the sodium polyepoxysuccinate is 40%, and the solid content of the sodium polyaspartate is 40%.

[0108] The solid content of the maleic acid-acrylic acid copolymer is 55 wt %, and the free monomer content calculated as maleic acid is ≤ 9.0 wt %.

[0109] A method for preparing an environmentally friendly reverse osmosis antiscalant further comprises the following steps:

[0110] S1, mixing crotonic acid-acrylamide-hydroxypropyl acrylate copolymer, sulfonic acid methylamino polyepoxysuccinic acid, and maleic acid-acrylic acid copolymer in a mass ratio of 1.2:1.5:2.5;

[0111] S2, heat the mixture obtained in S1 to 75-90°C, add fatty alcohol polyoxyethylene ether dropwise at a uniform rate within 2-3 hours, and perform ultrasonic treatment for 30-50 minutes.

[0112] S3, then raise the temperature to 95-100°C, add sodium polyepoxysuccinate and sodium polyaspartate, reflux for 2-2.5h, then cool the material to 60-65°C, and cool the filtrate to room temperature, which is an environmentally friendly reverse osmosis scale inhibitor.

[0113] Comparative Example 1

[0114] The difference between this comparative example and Example 1 is that no butenoic acid-acrylamide-hydroxypropyl acrylate copolymer is added to the raw materials of the environmentally friendly reverse osmosis antiscalant.

[0115] Comparative Example 2

[0116] The difference between this comparative example and Example 1 is that sulfonic acid methylamino polyepoxysuccinic acid is not added to the raw materials of the environmentally friendly reverse osmosis antiscalant.

[0117] Comparative Example 3

[0118] The difference between this comparative example and Example 1 is that no maleic acid-acrylic acid copolymer is added to the raw materials of the environmentally friendly reverse osmosis antiscalant.

[0119] Experimental method: The experimental samples are the environmentally friendly reverse osmosis antiscalants prepared in Examples 1-5 and Comparative Examples 1-3. The test results are shown in Table 1 below:

[0120]

[0121]

[0122] CaCO 3 Performance measurement

[0123] Principle of calcium carbonate precipitation method: Prepare the test solution with prepared water containing a certain amount of bicarbonate and calcium ions and scale inhibitor. Under heating conditions, calcium bicarbonate is accelerated to decompose into CaCO 3 After reaching equilibrium, measure the Ca in the test solution. 2+ Concentration, Ca 2+ The higher the concentration, the better the scale inhibition performance of the agent.

[0124] Static resistance CaCO 3 Test conditions: Use deionized water to prepare 500ml of 5mg / L antiscalant, Ca 2+ Mass concentration 260mg / L, HCO 3- The mass concentration was 760 mg / L, and the pH was adjusted to 9.0 with sodium hydroxide, then placed in a constant temperature water bath at 80°C for 10 hours, cooled, filtered with a 0.22 μm microporous filter, and the Ca was determined by the EDTA method. 2+ concentration and perform a blank test at the same time.

[0125] CaSO4 resistance performance determination

[0126] Test conditions: Use deionized water to prepare 500ml of 5mg / L antiscalant, Ca 2+ Mass concentration 260mg / L, SO 4 2- The mass concentration was 760 mg / L, and the pH was adjusted to 9.0 with sodium hydroxide, then placed in a constant temperature water bath at 80°C for 10 hours, cooled, filtered with a 0.22 μm microporous filter, and the Ca was determined by the EDTA method. 2+ concentration and perform a blank test at the same time.

[0127] Corrosion inhibition test

[0128] Test water: total hardness 645mg / L, Ca2+ 455mg / L, total alkalinity 348mg / L, SO 4 2-It is 140mg / L, and Cl- is 131mg / L.

[0129] Dosage: 20mg / L

[0130] Test method: Rotating hanging piece weight loss method: Corrosion inhibition performance is evaluated according to HG / T2159-91 method, test temperature: 50℃, rotation speed: 80r / min, test time: 72h, material is stainless steel.

[0131] Calculation of COD removal rate:

[0132] The COD was determined using the “Determination of Chemical Oxygen Demand in Water - Dichromate Method” (HJ828-2017).

[0133] The test results show that when the above raw material ratio and process parameters are used, the environmentally friendly reverse osmosis antiscalant obtained has a CaCO 3 Scale inhibition performance, CaSO 4 The comprehensive performances such as scale inhibition performance and COD removal performance are greatly improved compared with the comparative example; and the corrosion rate of the reverse osmosis membrane is relatively small, which is completely superior to the comparative example. Among them, the environmentally friendly reverse osmosis scale inhibitor prepared in Example 3 has the best comprehensive performance.

[0134] The above description is only a preferred specific implementation manner of the present invention, but the protection scope of the present invention is not limited thereto. Any technician familiar with the technical field can make equivalent replacements or changes according to the technical scheme and inventive concept of the present invention within the technical scope disclosed by the present invention, which should be covered by the protection scope of the present invention.

Claims

1. An environmentally friendly reverse osmosis antiscalant, characterized in that: The environmentally friendly reverse osmosis antiscalant is made of the following raw materials in parts by weight: 40 parts of crotonic acid-acrylamide-hydroxypropyl acrylate copolymer, 25 parts of sulfonic acid methylamino polyepoxysuccinic acid, 15 parts of maleic acid-acrylic acid copolymer, 10 parts of sodium polyepoxysuccinate, 10 parts of sodium polyaspartate, and 8 parts of fatty alcohol polyoxyethylene ether; The butenoic acid-acrylamide-hydroxypropyl acrylate copolymer is obtained by polymerizing three monomers: butenoic acid, acrylamide and hydroxypropyl acrylate, and the weight ratio of the three monomers is 11:7:8; The preparation method of the butenoic acid-acrylamide-hydroxypropyl acrylate copolymer comprises the following steps: S1. adding isopropanol to water at 65-85° C. to obtain a reaction system; S2, adding the mixed monomer and initiator dropwise to the reaction system; S3, after the mixed monomer and initiator are added dropwise, the system is heated to 90-110°C and kept warm for reaction for 3-5 hours to obtain a butenoic acid-acrylamide-hydroxypropyl acrylate copolymer; The initiator is persulfate, and the amount of the initiator is 1% of the total weight of the mixed monomers; The persulfate is ammonium persulfate or potassium persulfate; The solid content of the sodium polyepoxysuccinate is 40%, and the solid content of the sodium polyaspartate is 40%; The solid content of the maleic acid-acrylic acid copolymer is 50wt%, and the free monomer content calculated as maleic acid is ≤9.0wt%; The method for preparing the environmentally friendly reverse osmosis antiscalant further comprises the following steps: S1, mixing crotonic acid-acrylamide-hydroxypropyl acrylate copolymer, sulfonic acid methylamino polyepoxysuccinic acid, and maleic acid-acrylic acid copolymer in a mass ratio of 1.2:1.3:2.3; S2, heating the mixture obtained in S1 to 75-90°C, adding fatty alcohol polyoxyethylene ether dropwise at a uniform rate within 2-3 hours, and ultrasonically treating for 30-50 minutes; S3, then raise the temperature to 95-100°C, add sodium polyepoxysuccinate and sodium polyaspartate, reflux for 2-2.5h, then cool the material to 60-65°C, and cool the filtrate to room temperature, which is an environmentally friendly reverse osmosis scale inhibitor; The environmentally friendly reverse osmosis antiscalant has a CaCO3 antiscaling rate of 99.3%, a CaSO4 antiscaling rate of 99.4%, and a corrosion rate of 1.15 g / (m 2 h), COD removal rate is 75.5%, among which, the environmentally friendly reverse osmosis antiscalant has the comprehensive performance of CaCO3 antiscaling performance, CaSO4 antiscaling performance and COD removal performance.

Images