Reverse osmosis phosphorus-free environment-friendly scale inhibitor as well as preparation method and application thereof

Abstract

The invention discloses a reverse osmosis phosphorus-free environment-friendly scale inhibitor, and belongs to the technical field of water treatment agents. The scale inhibitor comprises the following components in percentage by mass: 1%-5% of sodium carboxymethyl cellulose, 2%-8% of sodium lignin sulfonate, 3%-10% of an aminopropanesulfonic acid-acrylic acid copolymer, 4%-12% of a maleic acid-acrylic acid copolymer, 1%-6% of tartaric acid, 0.1%-1% of potassium iodide, 2%-7% of a first solvent, 1%-5% of a second solvent, 0.5%-3% of a corrosion inhibitor and 0.5%-2% of a pH regulator. Through innovative combination of a composite dispersion system, a bi-copolymer scale inhibition system, a chelation-corrosion inhibition synergistic system and a solvent-assistant adaptation system, full-demand coverage of scale inhibition-dispersion-corrosion inhibition-dissolution-stabilization is realized, and the scale inhibitor has the advantages of no phosphorus, environmental protection, high adaptability, high efficiency and low consumption; the defects of function fragmentation, poor environmental protection property and weak adaptability in the prior art are overcome, and the method can be widely applied to membrane treatment systems of reverse osmosis, nanofiltration and the like.

Description

Technical Field

[0001] This invention relates to the field of water treatment agents, specifically to a reverse osmosis phosphorus-free environmentally friendly scale inhibitor, its preparation method, and its application. Background Technology

[0002] Reverse osmosis membrane technology uses a semi-permeable membrane as its core. It separates the solute from the solvent by applying external pressure higher than the osmotic pressure of the solution, thereby achieving concentration and purification. As a highly efficient, low-energy-consumption, easy-to-operate, and pollution-free water treatment technology, reverse osmosis membrane technology is widely used in seawater desalination, wastewater reuse, and chemical and pharmaceutical industries.

[0003] In recent years, with breakthroughs in membrane material preparation technology and optimization of process parameters, the comprehensive performance indicators of reverse osmosis membranes, such as water permeability, separation efficiency, and operational durability, have significantly improved. This provides technical support for energy efficiency optimization and cost control in various application scenarios. However, in practical engineering applications, the deposition of contaminants on the membrane surface remains a key factor restricting the stable operation of the system. During the transmembrane mass transfer of water molecules, suspended organic matter, microbial metabolites, and dissolved inorganic salts form a dynamic adsorption layer at the membrane-liquid interface. Although the shearing action of the concentrate side can remove some of the deposits on the membrane surface, colloidal particles and biomolecules will still form a dense fouling layer on the membrane surface through hydrogen bonds, van der Waals forces, and other interactions. As the operating cycle extends, membrane pore blockage caused by the complex fouling layer will lead to a decrease in permeate flux, damage to membrane element structure, and a reduction in service life. Periodic chemical cleaning, on the other hand, will generate dual pressures of equipment downtime losses and reagent costs.

[0004] To ensure the economical, safe, stable, and long-term operation of reverse osmosis systems, it is necessary to select appropriate antiscalants specifically for reverse osmosis membrane modules to reduce the tendency of scaling in reverse osmosis systems and meet the urgent domestic market demand for domestically produced antiscalants specifically for reverse osmosis.

[0005] Scale inhibitors are key agents in industrial water treatment to prevent scaling and corrosion of equipment, and are widely used in reverse osmosis membrane separation, nanofiltration purification, industrial circulating water cooling and other scenarios. In the prior art, Chinese patent application CN 114427095 A discloses a scale inhibitor formulation containing hydrolyzed polymaleic anhydride, sulfonate copolymer, zinc salt, and tartrate. This zinc-containing composition suffers from poor biodegradability (sulfonate copolymer is difficult to degrade and easily causes secondary water pollution), a narrow range of suitable water qualities (only effective against carbonate scale, with no effective dispersion for calcium phosphate and sludge), and weak corrosion inhibition (lacking dedicated auxiliary corrosion inhibitors, resulting in insufficient corrosion protection for metal equipment). CN 114920367 A discloses a high-temperature resistant scale inhibitor containing modified sodium carboxymethyl cellulose, acrylic acid-2-acrylamide-2-methylpropanesulfonic acid copolymer, polymaleic anhydride, etc., but suffers from functional limitations (focusing on scale inhibition but lacking dispersion, easily leading to scale particle aggregation and adhesion), poor component synergy (failing to form a "scale inhibition-dispersion-corrosion inhibition" closed loop, with significant effect attenuation under high pH fluctuations), and insufficient environmental friendliness (poor biocompatibility of modified polymer components).

[0006] Therefore, developing a phosphorus-free, environmentally friendly, multifunctional, and highly adaptable corrosion and scale inhibitor has become a pressing technical problem to be solved in this field. Summary of the Invention

[0007] The purpose of this invention is to address the shortcomings of existing scale inhibitors, such as poor biodegradability, functional fragmentation, weak adaptability, and insufficient corrosion inhibition effect, by providing a reverse osmosis phosphorus-free environmentally friendly scale inhibitor that covers all needs of "scale inhibition-dispersion-corrosion inhibition-dissolution-stabilization" while improving environmental friendliness and adaptability to multiple scenarios.

[0008] To achieve the above objectives, the present invention provides the following technical solution: A reverse osmosis phosphorus-free environmentally friendly scale inhibitor, comprising the following components by weight percentage: sodium carboxymethyl cellulose 1%-5%, sodium lignosulfonate 2%-8%, aminopropanesulfonic acid-acrylic acid copolymer 3%-10%, maleic acid-acrylic acid copolymer 4%-12%, tartaric acid 1%-6%, potassium iodide 0.1%-1%, first solvent 2%-7%, second solvent 1%-5%, corrosion inhibitor 0.5%-3%, and pH adjuster 0.5%-2%.

[0009] Preferably, the reverse osmosis phosphorus-free environmentally friendly scale inhibitor of the present invention is composed of the following components by mass percentage: sodium carboxymethyl cellulose 1%-5%, sodium lignosulfonate 2%-8%, aminopropanesulfonic acid-acrylic acid copolymer 3%-10%, maleic acid-acrylic acid copolymer 4%-12%, tartaric acid 1%-6%, potassium iodide 0.1%-1%, first solvent 2%-7%, second solvent 1%-5%, corrosion inhibitor 0.5%-3%, pH adjuster 0.5%-2%, and deionized water as the balance.

[0010] Preferably, the pH adjuster is sodium citrate, but it is not limited thereto.

[0011] The corrosion inhibitor is benzotriazole.

[0012] The first solvent is methanol.

[0013] The second solvent is acetone.

[0014] On the other hand, the present invention also provides a method for preparing the aforementioned reverse osmosis phosphorus-free environmentally friendly scale inhibitor, which includes the following steps: S1. Add sodium carboxymethyl cellulose and sodium lignosulfonate sequentially to deionized water and stir until completely dissolved; heat to 40°C. S2. Add aminopropanesulfonic acid-acrylic acid copolymer, maleic acid-acrylic acid copolymer, and tartaric acid, and stir. S3. Cool to room temperature, add potassium iodide, methanol, acetone, and benzotriazole, and stir. S4. Add sodium citrate, adjust the pH to 6.8-7.5, stir, let stand and filter to obtain the reverse osmosis phosphorus-free environmentally friendly scale inhibitor.

[0015] Preferably, in step S2, the stirring time is 30 minutes.

[0016] Preferably, in step S3, the stirring time is 20 minutes.

[0017] On the other hand, the present invention also provides the application of the aforementioned reverse osmosis phosphorus-free environmentally friendly scale inhibitor in water treatment.

[0018] In this invention, the reverse osmosis phosphorus-free environmentally friendly scale inhibitor comprises a composite dispersion system of sodium carboxymethyl cellulose and sodium lignosulfonate. Sodium carboxymethyl cellulose has good water solubility and low cost, and can thicken and stabilize the formulation, while sodium lignosulfonate is natural, environmentally friendly, and biodegradable. The two work synergistically to enhance the suspension of scale particles, preventing their adhesion to equipment surfaces. A dual copolymer scale inhibitor system is formed by aminopropanesulfonic acid-acrylic acid copolymer and maleic acid-acrylic acid copolymer. The former disrupts the crystalline structure of calcium carbonate and calcium sulfate, exhibiting high-temperature resistance and hydrolysis resistance, while the latter disperses calcium phosphate, iron oxide, and sludge. Their functions are complementary, covering various types of insoluble scale. Tartaric acid gently chelates calcium, magnesium, and iron ions in water, preventing scale formation, and its biodegradability is superior to synthetic chelating agents. Potassium iodide assists in corrosion inhibition, suppressing metal electrochemical corrosion, and synergistically enhances metal protection with the specialized corrosion inhibitor benzotriazole. Methanol and acetone synergistically dissolve insoluble components such as copolymers and corrosion inhibitors, exhibiting moderate volatility and leaving no residue. A pH adjuster, such as sodium citrate, is used as an adjuvant to flexibly adjust the pH value of the formulation, adapting to different application scenarios. All ingredients are phosphorus-free, and the core environmentally friendly components have a biodegradability rate of ≥90%, preventing eutrophication pollution of water bodies. The synergistic effects of each component significantly improve the scale inhibition rate.

[0019] Compared with the prior art, the present invention has the following beneficial effects: (1) Phosphorus-free and environmentally friendly: The core components, sodium lignosulfonate and tartaric acid, are both biodegradable substances with a degradation rate of over 90%, which is in line with environmental protection policies and solves the problem of secondary pollution of existing technologies. (2) Full-function synergy: It achieves full coverage of the needs of "scale inhibition-dispersion-corrosion inhibition-dissolution-stabilization", and the components form an inseparable synergistic system with a scale inhibition rate of ≥98% and a comprehensive performance that is significantly better than the existing technology; (3) Extremely adaptable: High temperature resistance (≤120℃), hydrolysis resistant, can adapt to the conventional and medium-high temperature working conditions of reverse osmosis / nanofiltration system, and can cope with the wide water quality fluctuation of pH 3-10, and can simultaneously meet the usage requirements of different scenarios such as reverse osmosis membranes and nanofiltration equipment; (4) High efficiency and low consumption: The key components are highly compatible, and the total amount of effective ingredients is reduced by 15%-20% compared with existing technologies, which reduces the cost of use while improving the stability of efficacy. Detailed Implementation

[0020] To facilitate understanding of the present invention, a more complete description will be given below with reference to specific embodiments. Preferred embodiments of the invention are provided. However, the invention can be implemented in many different forms and is not limited to the embodiments described herein. Rather, these embodiments are provided to provide a thorough and complete understanding of the disclosure of the invention.

[0021] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. The terminology used herein in the description of the invention is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention.

[0022] Unless otherwise specified, the experimental methods used in the following examples and comparative examples are conventional methods, and the materials and reagents used are commercially available unless otherwise specified.

[0023] Aminopropanesulfonic acid Acrylic acid copolymer (AA / AMPS): a polymer obtained by free radical copolymerization of acrylic acid (AA) and 2-acrylamide-2-methylpropanesulfonic acid (AMPS); CAS No.: 40623-75-4.

[0024] Maleic acid-acrylic acid copolymer (MA / AA): A polymer synthesized by copolymerization of maleic acid and acrylic acid; CAS No.: 29132-58-9.

[0025] Example 1 A reverse osmosis phosphorus-free environmentally friendly scale inhibitor has the following formulation composition (by weight): Sodium carboxymethyl cellulose 2%, sodium lignosulfonate 3%, aminopropanesulfonic acid-acrylic acid copolymer 8%, maleic acid-acrylic acid copolymer 10%, tartaric acid 3%, potassium iodide 0.3%, methanol 4%, acetone 2%, benzotriazole 2%, sodium citrate 0.5%, and the remainder is deionized water.

[0026] The preparation method is as follows: Deionized water was added to the reactor, followed by sodium carboxymethyl cellulose and sodium lignosulfonate, and stirred until completely dissolved. The temperature was raised to 40°C, and aminopropanesulfonic acid-acrylic acid copolymer, maleic acid-acrylic acid copolymer, and tartaric acid were added, and stirred for 30 minutes. The temperature was lowered to room temperature, and potassium iodide, methanol, acetone, and benzotriazole were added, and stirred for 20 minutes. Finally, sodium citrate was added to adjust the pH to 6.8, and the mixture was stirred for 15 minutes before being allowed to stand and filtered to obtain the final product.

[0027] Test conditions: water temperature 35℃, pH 7.0, reverse osmosis membrane pressure 0.8MPa, feed water hardness (calculated as CaCO3) 350mg / L, test cycle 96h.

[0028] Test results: scale inhibition rate 99.1%, membrane permeate flux decay rate 2.3%, no sedimentation after 168 h of formulation storage, and biodegradation rate 92%.

[0029] Example 2 A reverse osmosis phosphorus-free environmentally friendly scale inhibitor has the following formulation composition (by weight): Sodium carboxymethyl cellulose 4%, sodium lignosulfonate 6%, aminopropanesulfonic acid-acrylic acid copolymer 10%, maleic acid-acrylic acid copolymer 12%, tartaric acid 6%, potassium iodide 0.8%, methanol 7%, acetone 5%, benzotriazole 3%, sodium citrate 0.5%, and the remainder is deionized water.

[0030] Preparation method: Same as in Example 1, except that the pH is adjusted to 7.0.

[0031] Test conditions: water temperature 70℃, pH 8.5, reverse osmosis membrane pressure 1.0MPa, feed water hardness (calculated as CaCO3) 800mg / L, test cycle 96h; Test results: scale inhibition rate 98.7%, membrane permeate flux decay rate 1.5%, no sedimentation after 168 h of formulation storage, and biodegradation rate 89%.

[0032] Example 3 A reverse osmosis phosphorus-free environmentally friendly scale inhibitor has the following formulation composition (by weight): Sodium carboxymethyl cellulose 3%, sodium lignosulfonate 4%, aminopropanesulfonic acid-acrylic acid copolymer 7%, maleic acid-acrylic acid copolymer 9%, tartaric acid 5%, potassium iodide 0.4%, methanol 3%, acetone 3%, benzotriazole 1.6%, sodium citrate 0.8%, and the remainder is deionized water.

[0033] Preparation method: Same as in Example 1, except that the pH is adjusted to 7.2.

[0034] Test conditions: water temperature 40℃, pH 6.0, nanofiltration membrane pressure 0.6 MPa, influent calcium ion content 180mg / L + magnesium ion content 100mg / L, test cycle 96h.

[0035] Test results: scale inhibition rate 98.8%, membrane permeate flux decay rate 0.5%, no sedimentation after 168 h of formulation storage, and biodegradation rate 91%.

[0036] Example 4 A reverse osmosis phosphorus-free environmentally friendly scale inhibitor has the following formulation composition (by weight): Sodium carboxymethyl cellulose 5%, sodium lignosulfonate 8%, aminopropanesulfonic acid-acrylic acid copolymer 9%, maleic acid-acrylic acid copolymer 8%, tartaric acid 4%, potassium iodide 1.0%, methanol 6%, acetone 4%, benzotriazole 2.5%, sodium citrate 1%, and the remainder is deionized water.

[0037] Preparation method: Same as in Example 1, except that the pH is adjusted to 7.5.

[0038] Test conditions: water temperature 50℃, pH 7.5, nanofiltration membrane pressure 0.7MPa, influent containing sulfate ions 350mg / L + calcium ions 220mg / L, test cycle 96h.

[0039] Test results: scale inhibition rate 99.0%, membrane permeate flux decay rate 3.1%, no sedimentation after 168 h of formulation storage, and biodegradation rate 92%.

[0040] Example 5 A reverse osmosis phosphorus-free environmentally friendly scale inhibitor has the following formulation composition (by weight): Sodium carboxymethyl cellulose 1%, sodium lignosulfonate 2%, aminopropanesulfonic acid-acrylic acid copolymer 8%, maleic acid-acrylic acid copolymer 10%, tartaric acid 3%, potassium iodide 0.3%, methanol 5%, acetone 2%, benzotriazole 1.5%, sodium citrate 0.7%, and the remainder is deionized water.

[0041] Preparation method: Same as in Example 1, except pH is adjusted to 6.9.

[0042] Test conditions: water temperature 30℃, pH 10, reverse osmosis membrane pressure 0.7MPa, feed water hardness (calculated as CaCO3) 250mg / L, test cycle 96h.

[0043] Test results: scale inhibition rate 98.2%, membrane permeate flux decay rate 3.5%, no sedimentation after 168 hours of formulation placement, and biodegradation rate 90%.

[0044] Example 6 A reverse osmosis phosphorus-free environmentally friendly scale inhibitor has the following formulation composition (by weight): Sodium carboxymethyl cellulose 3%, sodium lignosulfonate 5%, aminopropanesulfonic acid-acrylic acid copolymer 3%, maleic acid-acrylic acid copolymer 4%, tartaric acid 4%, potassium iodide 0.4%, methanol 6%, acetone 3%, benzotriazole 2%, sodium citrate 0.6%, and the remainder is deionized water.

[0045] Preparation method: Same as in Example 1, except pH is adjusted to 7.1.

[0046] Test conditions: water temperature 45℃, pH 5.0, nanofiltration membrane pressure 0.5MPa, influent calcium ion content 120mg / L + magnesium ion content 80mg / L, test cycle 96h.

[0047] Test results: scale inhibition rate 98.0%, membrane permeate flux decay rate 2.8%, no sedimentation after 168 hours of formulation storage, and biodegradation rate 91%.

[0048] Example 7 A reverse osmosis phosphorus-free environmentally friendly scale inhibitor has the following formulation composition (by weight): Sodium carboxymethyl cellulose 2%, sodium lignosulfonate 4%, aminopropanesulfonic acid-acrylic acid copolymer 7%, maleic acid-acrylic acid copolymer 8%, tartaric acid 1%, potassium iodide 0.1%, methanol 7%, acetone 4%, benzotriazole 2.5%, sodium citrate 2.0%, and the remainder is deionized water.

[0049] Preparation method: Same as in Example 1, except pH is adjusted to 7.3.

[0050] Test conditions: water temperature 60℃, pH 4.5, reverse osmosis membrane pressure 0.9MPa, feed water containing 280mg / L sulfate ions + 180mg / L calcium ions, test cycle 96h.

[0051] Test results: scale inhibition rate 98.3%, membrane permeate flux decay rate 3.0%, no sedimentation after 168 hours of formulation placement, and biodegradation rate 90%.

[0052] Example 8 A reverse osmosis phosphorus-free environmentally friendly scale inhibitor has the following formulation composition (by weight): Sodium carboxymethyl cellulose 4%, sodium lignosulfonate 6%, aminopropanesulfonic acid-acrylic acid copolymer 6%, maleic acid-acrylic acid copolymer 7%, tartaric acid 2%, potassium iodide 0.2%, methanol 2%, acetone 1%, benzotriazole 0.5%, sodium citrate 0.5%, and the remainder is deionized water.

[0053] Preparation method: Same as in Example 1, except pH is adjusted to 7.4.

[0054] Test conditions: water temperature 55℃, pH 5.5, nanofiltration membrane pressure 0.65MPa, influent hardness (calculated as CaCO3) 500mg / L, test cycle 96h.

[0055] Test results: scale inhibition rate 98.1%, membrane permeate flux decay rate 3.2%, no sedimentation after 168 hours of formulation placement, and biodegradation rate 91%.

[0056] Comparative Example 1 Scale inhibitor formulation and preparation method: Sodium lignosulfonate is omitted, otherwise the same as in Example 1.

[0057] Test conditions: Same as in Example 1.

[0058] Test results: scale inhibition rate 82.3%, membrane permeate flux decay rate 18.7%, turbidity appeared after 168 hours, and biodegradation rate 61%.

[0059] Comparative Example 2 Scale inhibitor formulation and preparation method: The aminopropanesulfonic acid-acrylic acid copolymer was replaced with an equal amount of sulfonate copolymer (acrylic acid, 2-acrylamide-2-methylpropanesulfonic acid and hydroxypropyl acrylate copolymer, with a limiting viscosity of 0.069 dL / g at 30°C and a solid content of 43% by weight, purchased from Shandong Taihe Water Treatment Co., Ltd.), and the rest was the same as in Example 2.

[0060] Test conditions: Same as in Example 2 (pH 9).

[0061] Test results: scale inhibition rate 85.7%, membrane permeate flux decay rate 71.2%, turbidity appeared after 168 hours, and biodegradation rate 38%.

[0062] Comparative Example 3 Scale inhibitor formulation and preparation method: Maleic acid-acrylic acid copolymer is omitted, otherwise the same as in Example 3.

[0063] Test conditions: Same as in Example 3.

[0064] Test results: scale inhibition rate 84.6%, membrane permeate flux decay rate 15.2%, turbidity appeared after 168 hours, and biodegradation rate 88%.

[0065] Comparative Example 4 Scale inhibitor formulation and preparation method: Sodium carboxymethyl cellulose and sodium lignosulfonate were replaced with modified sodium carboxymethyl cellulose in equal amounts, and the rest was the same as in Example 4.

[0066] Preparation of modified sodium carboxymethyl cellulose: 242.16 g of sodium carboxymethyl cellulose was added to 2179.44 g of water to prepare a 10 wt% aqueous solution of sodium carboxymethyl cellulose; then 11.42 g of ammonium persulfate and 242.16 g of acrylamide were added and stirred until homogeneous; the reaction was carried out at 70 °C for 4 hours under a nitrogen atmosphere, and then 1210.8 g of acetone was added to precipitate and separate the product, thus obtaining modified sodium carboxymethyl cellulose A.

[0067] Test conditions: Same as in Example 4.

[0068] Test results: scale inhibition rate 88.5%, membrane permeate flux decay rate 16.8%, turbidity appeared after 168 hours, and biodegradation rate 42%.

[0069] The test results above show that the composite dispersion system of sodium lignosulfonate and sodium carboxymethyl cellulose is key to preventing film scaling; the copolymer of this invention is suitable for a wide range of pH and high temperatures, avoiding hydrolysis failure at high temperatures, which is superior to the existing sulfonate copolymers; the maleic acid-acrylic acid copolymer is the core for dispersing insoluble scale, and its copolymer system with aminopropanesulfonic acid-acrylic acid copolymer is the key to ensuring wide water quality compatibility; the composite dispersion system of this invention has significantly better environmental protection and stability than the existing technology.

Claims

1. A reverse osmosis phosphorus-free environmentally friendly scale inhibitor, characterized in that, By weight percentage, it comprises the following components: sodium carboxymethyl cellulose 1%-5%, sodium lignosulfonate 2%-8%, aminopropanesulfonic acid-acrylic acid copolymer 3%-10%, maleic acid-acrylic acid copolymer 4%-12%, tartaric acid 1%-6%, potassium iodide 0.1%-1%, first solvent 2%-7%, second solvent 1%-5%, corrosion inhibitor 0.5%-3%, and pH adjuster 0.5%-2%.

2. The reverse osmosis phosphorus-free environmentally friendly scale inhibitor according to claim 1, characterized in that, It consists of the following components: sodium carboxymethyl cellulose 1%-5%, sodium lignosulfonate 2%-8%, aminopropanesulfonic acid-acrylic acid copolymer 3%-10%, maleic acid-acrylic acid copolymer 4%-12%, tartaric acid 1%-6%, potassium iodide 0.1%-1%, first solvent 2%-7%, second solvent 1%-5%, corrosion inhibitor 0.5%-3%, pH adjuster 0.5%-2%, and the balance being water.

3. The reverse osmosis phosphorus-free environmentally friendly scale inhibitor according to claim 1, characterized in that, The pH adjuster is sodium citrate.

4. The reverse osmosis phosphorus-free environmentally friendly scale inhibitor according to claim 1, characterized in that, The corrosion inhibitor is benzotriazole.

5. The reverse osmosis phosphorus-free environmentally friendly scale inhibitor according to claim 1, characterized in that, The first solvent is methanol.

6. The reverse osmosis phosphorus-free environmentally friendly scale inhibitor according to claim 1, characterized in that, The second solvent is acetone.

7. A method for preparing a reverse osmosis phosphorus-free environmentally friendly scale inhibitor as described in any one of claims 1 to 6, characterized in that, Includes the following steps: S1. Add sodium carboxymethyl cellulose and sodium lignosulfonate sequentially to deionized water and stir until completely dissolved; heat to 40°C. S2. Add aminopropanesulfonic acid-acrylic acid copolymer, maleic acid-acrylic acid copolymer, and tartaric acid, and stir. S3. Cool to room temperature, add potassium iodide, methanol, acetone, and benzotriazole, and stir. S4. Add sodium citrate, adjust the pH to 6.8-7.5, stir, let stand and filter to obtain the reverse osmosis phosphorus-free environmentally friendly scale inhibitor.

8. The method according to claim 7, characterized in that, In step S2, the stirring time is 30 minutes.

9. The method according to claim 7, characterized in that, In step S3, the stirring time is 20 minutes.

10. The application of the reverse osmosis phosphorus-free environmentally friendly scale inhibitor as described in any one of claims 1 to 9 in water treatment.