Special reverse osmosis scale inhibitor for high-silicon water and preparation method thereof

Abstract

The invention provides a special reverse osmosis scale inhibitor for high-silicon water and a preparation method thereof, and the scale inhibitor comprises the following raw materials by mass: 40-65 wt% of polyamino polyether methylene phosphonic acid, 5-18 wt% of 2-hydroxyphosphonoacetic acid, 2-15 wt% of 2-phosphoric acid-1, 2, 4-tricarboxylic acid butane, 3-20 wt% of polyepoxysuccinic acid, 2-30 wt% of a sulfonate copolymer and 1-30 wt% of an acrylic polymer. The scale inhibitor reduces the energy consumption of a reverse osmosis system increased due to membrane pollution by reducing the formation of silicon scale, and can meet the environment-friendly requirement.

Description

Technical Field

[0001] The invention belongs to the technical field of sewage treatment, and in particular to a reverse osmosis scale inhibitor specially used for high-silicon water and a preparation method thereof. Background Art

[0002] In the field of water treatment, reverse osmosis technology is the most mature physical desalination technology in water treatment and desalination processes. It is widely used, especially in desalinating seawater, treating industrial wastewater and producing pure water. However, when treating water containing highly soluble silicon, the reverse osmosis system faces severe membrane pollution challenges. Soluble silicon is easy to deposit on the surface of the reverse osmosis membrane and gradually transform into hard and difficult to remove silicon scale.

[0003] The formation of silica scale will not only reduce the flux of the membrane, increase the transmembrane pressure difference, and cause a significant decrease in the water output of the reverse osmosis system, but also seriously affect the salt removal efficiency of the reverse osmosis membrane, making the desalination effect significantly reduced. This performance deterioration is very important for industries that have extremely strict requirements on water quality, such as the electronics industry and the pharmaceutical industry. It may lead to a decline in product quality, thereby increasing production costs and affecting the market competitiveness of products.

[0004] At the same time, the interaction between silica scale and other pollutants may further damage the membrane structure, aggravate salt penetration, and further reduce the desalination effect. The silicon in high-silicon water will also react chemically with other substances in the water to produce acidic or alkaline substances, which will corrode the pipes, valves, pumps and other equipment in the reverse osmosis system, shorten their service life, increase maintenance and replacement costs, and may cause leakage in the reverse osmosis system, causing pollution to the surrounding environment.

[0005] In addition, what is more complicated is that soluble silicon combines with metal ions such as calcium, magnesium, iron and organic matter to form complex pollutants that are more difficult to treat. These pollutants not only increase the degree of reverse osmosis membrane pollution, but also make cleaning more difficult. In severe cases, these pollutants may even cause physical damage to the reverse osmosis membrane, such as membrane rupture and perforation, which directly increases the cost of replacing reverse osmosis membrane elements.

[0006] In order to maintain the normal operation of the reverse osmosis system, the operating pressure has to be increased to overcome the resistance caused by membrane pollution, which will inevitably lead to a substantial increase in energy consumption, which not only increases operating costs but also aggravates the environmental burden. At the same time, the reduction in water production forces the equipment to extend its operating time, further pushing up the energy consumption level.

[0007] In view of this, the present invention is proposed. Summary of the invention

[0008] The first object of the present invention is to provide a reverse osmosis scale inhibitor specifically for high-silicon water, which can effectively inhibit the formation of silica scale in high-silicon water, protect the reverse osmosis membrane system, and improve the water treatment efficiency and the service life of the membrane.

[0009] The second object of the present invention is to provide a method for preparing the above-mentioned reverse osmosis scale inhibitor for high-silicon water quality. The preparation method is simple, the operation process is gentle, and no harmful substances are generated in the entire preparation process, thereby realizing a green and environmentally friendly production process.

[0010] In order to achieve the above-mentioned purpose of the present invention, the following technical solutions are particularly adopted: The invention provides a reverse osmosis scale inhibitor specially used for high-silicon water. The raw materials include, by mass percentage, 40-65wt% of polyaminopolyether methylenephosphonic acid, 5-18wt% of 2-hydroxyphosphonoacetic acid, 2-15wt% of 2-phosphoryl-1,2,4-tricarboxylic acid butane, 3-20wt% of polyepoxysuccinic acid, 2-30wt% of sulfonate copolymer and 1-30wt% of acrylic polymer.

[0011] Preferably, as a further implementable scheme, by mass percentage, polyaminopolyether methylenephosphonic acid 41-60wt%, 2-hydroxyphosphonoacetic acid 9-17wt%, 2-phosphoryl-1,2,4-tricarboxylic acid butane 3-13wt%, polyepoxysuccinic acid 4-16wt%, sulfonate copolymer 5-25wt%, and acrylic polymer 2-23wt%.

[0012] Preferably, as a further feasible scheme, by mass percentage, 65 wt % of polyaminopolyether methylenephosphonic acid, 6 wt % of 2-hydroxyphosphonoacetic acid, 5 wt % of 2-phosphoryl-1,2,4-tricarboxylic acid butane, 8 wt % of polyepoxysuccinic acid, 9 wt % of sulfonate copolymer, and 7 wt % of acrylic polymer.

[0013] Preferably, the sulfonate copolymer is any one of acrylic acid-2-acrylamide-2-methylpropanesulfonic acid copolymer, acrylic acid-2-acrylamide-2-methylpropanesulfonic acid-hydroxypropyl acrylate terpolymer, acrylic acid-2-acrylamide-2-methylpropanesulfonic acid-ethyl acetoacetate terpolymer, and acrylic acid-acrylate-sulfonate terpolymer.

[0014] Preferably, the acrylic polymer is any one of polyacrylic acid, acrylic acid-acrylamide copolymer, acrylic acid-acrylic ester copolymer, acrylic acid-maleic anhydride copolymer, and acrylic acid-hydroxypropyl acrylate copolymer.

[0015] Among the above raw materials, polyamino polyether methylene phosphonic acid plays a key role in the scale inhibitor. It has high chelating and dispersing properties and can effectively chelate and harden metal ions such as calcium and magnesium in water to form a stable complex. The formation of this complex prevents the metal ions from combining with anions such as silicate to form silica scale. At the same time, the functional groups in the polyamino polyether methylene phosphonic acid molecules can also occupy the position on the inorganic salt nucleus or microcrystal, hindering and destroying the normal growth of the crystal, slowing down the growth rate of the crystal, and thus reducing the formation of silica scale.

[0016] 2-Hydroxyphosphonoacetic acid is also an important component of the scale inhibitor of the present invention. The hydroxyl group and phosphono group in its molecule can react with metal ions such as calcium and magnesium in water to form a stable complex, which prevents these metal ions from combining with silicate, thereby effectively preventing the formation of silica scale. In addition, 2-Hydroxyphosphonoacetic acid can also form a protective film on the metal surface, slowing down the corrosion rate of the metal and further improving the service life of the equipment.

[0017] 2-Phosphate-1,2,4-tricarboxylic acid butane exhibits excellent scale inhibition performance under high temperature, high hardness and high alkalinity conditions, especially for silicon scale. It can also have a good synergistic corrosion inhibition effect with zinc salts, polyphosphates, etc., and can form a layer of water-insoluble corrosion inhibition film on the metal surface to inhibit metal corrosion.

[0018] Polyepoxysuccinic acid has good biodegradability and has good scale inhibition and dispersion properties for calcium carbonate, calcium sulfate, silica scale, etc. in water. It absorbs at the kink position of the crystal, occupies the lattice position of the normal growth of the crystal, inhibits the regular growth of the crystal, deforms the lattice, and generates loose soft scale that is difficult to form hard scale blocks.

[0019] Sulfonate copolymers have excellent dispersibility and scale inhibition properties. They can be adsorbed on the surface of silicate particles, and prevent the aggregation and deposition of particles through electrostatic repulsion and steric hindrance, thereby keeping the silicate particles in the water in a dispersed state and preventing inorganic salts from depositing on the membrane surface. At the same time, the sulfonic acid group also has a certain hydrophilicity, which helps to improve the wettability of the membrane surface and reduce the adhesion of the scale layer. In addition, sulfonate copolymers have a synergistic effect with other scale inhibitor components, which can further improve the overall scale inhibition effect.

[0020] Functional groups such as carboxyl groups on the molecular chain of acrylic polymers can react with metal ions in water to form a chelating reaction, and disperse the scaling substances in the water through dispersion to prevent them from depositing on the surface of the equipment. At the same time, acrylic polymers also prevent scaling substances from forming a dense scale layer on the surface of the equipment through electrostatic repulsion and steric hindrance.

[0021] The sum of the contents of the above components is 100wt%. Through the reasonable proportion of the above raw materials, the synergistic effect between the raw materials is fully exerted, which can effectively prevent and disperse inorganic salts such as silica scale in high-silicon water, and improve the service life and operation efficiency of the reverse osmosis membrane.

[0022] The present invention also provides a method for preparing the above-mentioned reverse osmosis scale inhibitor for high-silicon water, comprising the following steps: Polyaminopolyether methylenephosphonic acid, 2-hydroxyphosphonoacetic acid, 2-phospho-1,2,4-tricarboxylic acid butane, polyepoxysuccinic acid, sulfonate copolymer and acrylic polymer are added and mixed in sequence, and finally a special reverse osmosis scale inhibitor for high-silicon water quality is prepared.

[0023] Preferably, stirring is performed during the mixing step, and the stirring time is 20-30 minutes.

[0024] Preferably, after the stirring is completed, filtering and packaging are required, and then standing at room temperature.

[0025] Preferably, the standing time after the filtration and packaging process is 23-24 hours.

[0026] In the present invention, by limiting the various operating parameters in the preparation method, it is ensured that each step can be precisely controlled, from the accurate weighing of the raw materials to the uniformity of mixing and stirring, to the meticulous treatment of filtration, packaging and standing. Each step is carefully designed to maximize the synergistic effect between the components, thereby effectively improving the performance stability and production efficiency of the reverse osmosis antiscalant for high-silicon water quality, so as to achieve the best antiscaling effect.

[0027] Compared with the prior art, the present invention has the following beneficial effects: (1) The reverse osmosis scale inhibitor for high-silicon water provided by the present invention is a multi-efficient scale inhibitor composed of carefully selected and proportioned polyaminopolyether methylenephosphonic acid, 2-hydroxyphosphonoacetic acid, 2-phospho-1,2,4-tricarboxylic acid butane, polyepoxysuccinic acid, sulfonate copolymer and acrylic polymer. These components can form stable complexes with metal ions such as calcium and magnesium in water, effectively preventing the formation of silica scale and other inorganic salt scale. In particular, under the conditions of high silicon, high hardness and high alkalinity water quality, the scale inhibitor of the present invention exhibits a significant scale inhibition effect, greatly improving the service life and operating efficiency of the reverse osmosis membrane.

[0028] (2) The scale inhibitor components in the present invention not only have excellent scale inhibition performance, but also can produce good synergistic effects among them. This synergistic effect makes the scale inhibitor of the present invention have better performance than a single scale inhibitor or a simple mixed scale inhibitor under the same conditions.

[0029] (3) The special scale inhibitor for high-silicon water of the present invention can effectively prevent the formation of silicon scale on the surface of the reverse osmosis membrane, reduce the decline in the performance of the reverse osmosis membrane, maintain the flux and water quality of the reverse osmosis membrane, and extend the service life of the reverse osmosis membrane.

[0030] (4) Ingredients such as polyepoxysuccinic acid have good biodegradability and can be decomposed by microorganisms in the natural environment without causing environmental pollution. At the same time, the scale inhibitor of the present invention does not contain toxic and harmful substances, is safe and harmless to the human body and the environment, and conforms to the concept of green environmental protection.

[0031] (5) The preparation method of the present invention is simple and clear. The finished product can be obtained by sequentially adding and mixing the raw material components, and then stirring, filtering and packaging. At the same time, the present invention defines the operating parameters in the preparation process to ensure that each step can be accurately controlled, thereby ensuring the performance stability and production efficiency of the scale inhibitor.

[0032] (6) The scale inhibitor formula of the present invention is suitable for high-silicon water of different concentrations and types, has strong adaptability, and can maintain a stable scale inhibition effect under high temperature, high hardness or other complex water conditions. DETAILED DESCRIPTION

[0033] The technical scheme of the present invention will be clearly and completely described below in conjunction with specific embodiments, but it will be appreciated by those skilled in the art that the following described embodiments are some embodiments of the present invention, rather than all embodiments, and are only used to illustrate the present invention, and should not be considered as limiting the scope of the present invention. Based on the embodiments in the present invention, all other embodiments obtained by those of ordinary skill in the art without making creative work, all belong to the scope of protection of the present invention. If specific conditions are not indicated in the embodiments, they are carried out according to normal conditions or conditions recommended by the manufacturer. If the manufacturer is not indicated in the reagents or instruments used, they are all conventional products that can be purchased commercially.

[0034] Example 1 Take 55g of polyaminopolyether methylenephosphonic acid, 10g of 2-hydroxyphosphonoacetic acid, 8g of 2-phospho-1,2,4-tricarboxylic acid butane, 10g of polyepoxysuccinic acid, 8g of acrylic acid-2-acrylamide-2-methylpropanesulfonic acid copolymer, and 9g of acrylic acid-hydroxypropyl acrylate copolymer; Add the weighed raw materials into the reactor in sequence; Stir evenly at room temperature for 20 minutes to fully mix all components; After the mixing is completed, filter it through a micron filter and package it; Finally, let it stand at room temperature for 24 hours.

[0035] Example 2 Take 60g of polyaminopolyether methylenephosphonic acid, 8g of 2-hydroxyphosphonoacetic acid, 6g of 2-phospho-1,2,4-tricarboxylic acid butane, 12g of polyepoxysuccinic acid, 6g of acrylic acid-2-acrylamide-2-methylpropanesulfonic acid-hydroxypropyl acrylate terpolymer, and 8g of acrylic acid-acrylamide copolymer; Add the weighed raw materials into the reactor in sequence; Stir evenly at room temperature for 30 minutes to fully mix all components; After the mixing is completed, filter it through a micron filter and package it; Finally, let it stand at room temperature for 24 hours.

[0036] Example 3 Take 65g of polyaminopolyether methylenephosphonic acid, 6g of 2-hydroxyphosphonoacetic acid, 5g of 2-phospho-1,2,4-tricarboxylic acid butane, 8g of polyepoxysuccinic acid, 9g of acrylic acid-2-acrylamide-2-methylpropanesulfonic acid-methyl acetoacetic acid ethyl ester terpolymer, and 7g of polyacrylic acid; Add the weighed raw materials into the reactor in sequence; Stir evenly at room temperature for 30 minutes to fully mix all components; After the mixing is completed, filter it through a micron filter and package it; Finally, let it stand at room temperature for 24 hours.

[0037] Example 4 Take 40g of polyaminopolyether methylenephosphonic acid, 17g of 2-hydroxyphosphonoacetic acid, 13g of 2-phospho-1,2,4-tricarboxylic acid butane, 16g of polyepoxysuccinic acid, 5g of acrylic acid-2-acrylamide-2-methylpropanesulfonic acid-methyl acetoacetic acid ethyl ester terpolymer, and 9g of polyacrylic acid; Add the weighed raw materials into the reactor in sequence; Stir evenly at room temperature for 28 minutes to fully mix all components; After the mixing is completed, filter it through a micron filter and package it; Finally, let it stand at room temperature for 24 hours.

[0038] Example 5 Take 41g of polyaminopolyether methylenephosphonic acid, 17g of 2-hydroxyphosphonoacetic acid, 15g of 2-phospho-1,2,4-tricarboxylic acid butane, 20g of polyepoxysuccinic acid, 5g of acrylic acid-acrylate-sulfonate terpolymer, and 2g of acrylic acid-maleic anhydride copolymer; Add the weighed raw materials into the reactor in sequence; Stir evenly at room temperature for 22 minutes to fully mix all components; After the mixing is completed, filter it through a micron filter and package it; Finally, let it stand at room temperature for 24 hours.

[0039] Example 6 Take 50g of polyaminopolyether methylenephosphonic acid, 18g of 2-hydroxyphosphonoacetic acid, 3g of 2-phosphoryl-1,2,4-tricarboxylic acid butane, 3g of polyepoxysuccinic acid, 25g of acrylic acid-2-acrylamide-2-methylpropanesulfonic acid copolymer, and 1g of acrylic acid-acrylate copolymer; Add the weighed raw materials into the reactor in sequence; Stir evenly at room temperature for 24 minutes to fully mix all components; After the mixing is completed, filter it through a micron filter and package it; Finally, let it stand at room temperature for 24 hours.

[0040] Example 7 The specific implementation is consistent with Example 3, except that the acrylic acid-2-acrylamide-2-methylpropanesulfonic acid-ethyl acetoacetate methacrylate terpolymer is replaced with acrylic acid-acrylate-sulfonate terpolymer.

[0041] Example 8 The specific implementation is consistent with Example 3, except that the polyacrylic acid is replaced by acrylic acid-acrylate copolymer.

[0042] Comparative Example 1 Take 2g of polyaminopolyether methylenephosphonic acid, 1g of 2-hydroxyphosphonoacetic acid, 22g of 2-phospho-1,2,4-tricarboxylic acid butane, 23g of polyepoxysuccinic acid, 31g of acrylic acid-2-acrylamide-2-methylpropanesulfonic acid copolymer, and 21g of acrylic acid-acrylate copolymer; Add the weighed raw materials into the reactor in sequence; Stir evenly at room temperature for 25 minutes to fully mix all components; After the mixing is completed, filter it through a micron filter and package it; Finally, let it stand at room temperature for 24 hours.

[0043] Comparative Example 2 Take 20g of polyaminopolyether methylenephosphonic acid, 26g of 2-hydroxyphosphonoacetic acid, 21g of 2-phospho-1,2,4-tricarboxylic acid butane, 20g of polyepoxysuccinic acid, 9g of acrylic acid-acrylate-sulfonate terpolymer, and 4g of acrylic acid-maleic anhydride copolymer; Add the weighed raw materials into the reactor in sequence; Stir evenly at room temperature for 22 minutes to fully mix all components; After the mixing is completed, filter it through a micron filter and package it; Finally, let it stand at room temperature for 24 hours.

[0044] Comparative Example 3 Take 80g of polyaminopolyether methylenephosphonic acid, 4g of 2-hydroxyphosphonoacetic acid, 1g of 2-phospho-1,2,4-tricarboxylic acid butane, 11g of polyepoxysuccinic acid, 1g of acrylic acid-2-acrylamide-2-methylpropanesulfonic acid-hydroxypropyl acrylate terpolymer, and 3g of acrylic acid-acrylamide copolymer; Add the weighed raw materials into the reactor in sequence; Stir evenly at room temperature for 30 minutes to fully mix all components; After the mixing is completed, filter it through a micron filter and package it; Finally, let it stand at room temperature for 24 hours.

[0045] Experimental Example 1 The scale inhibition performance of the product of the present invention was measured. The scale inhibition performance of carbonate, sulfate and silicate were measured respectively; the water used for carbonate measurement was self-prepared water, and in the self-prepared water solution, Ca The content is 300mg / L, CO3 2- The content is 650mg / L; the water used for sulfate determination is self-prepared water. In the self-prepared water solution, Ca Content is 200mg / L, SO4 2- The content is 550mg / L; the water used for silicate determination is self-prepared water. In the self-prepared water solution, SiO4 2- Content: 35 mg / L (as SiO2).

[0046] The determination method of the scale inhibition performance of carbonate, sulfate and silicate scale inhibitors mentioned above refers to GB / T 16632-2019 "Determination of scale inhibition performance of water treatment agents - calcium carbonate precipitation method". The composition, content and scale inhibition performance test results of the scale inhibitors in each example are shown in Table 1.

[0047] Table 1

[0048] Based on the above data, we can draw the following conclusions: From the data of Examples 1 to 8, it can be seen that the scale inhibitor of the present invention has a significant effect on scales such as carbonate, sulfate and silicate in the reverse osmosis process for high-silicon water. In particular, the carbonate scale inhibition rate of all embodiments reached 100%, indicating that the present invention is very effective in preventing the formation of carbonate scale. The sulfate scale inhibition rate is also generally high, all above 96.3%, and Example 3 even reached more than 99%, showing the excellent effect of the present invention in preventing the formation of sulfate. The silicate scale inhibition rate is also relatively high, with the lowest being 78.8% in Example 1 and the highest being 89.7% in Example 3.

[0049] It can also be seen from the table that the dosage of the scale inhibitor also has a certain influence on the scale inhibition effect. Generally speaking, with the increase of the dosage, the scale inhibition rate shows an upward trend. In the embodiment, when the dosage increases from 3mg / L to 6mg / L, the silicate scale inhibition rate generally increases. This does not mean that the more the dosage, the better, because too high a dosage may increase the cost and may cause other effects on water quality. Therefore, a certain dosage range should be controlled in actual applications.

[0050] From the comparison of Comparative Examples 1 to 3, it can be seen that the content of each component is important for the scale inhibition performance. When the content of each component is within a carefully designed range, it can exert its better scale inhibition performance. However, when the content of one or more components is too high or too low, the scale inhibition performance of the present invention will decrease and it will not be able to exert its excellent role.

[0051] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or replace some or all of the technical features therein with equivalents. However, these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A reverse osmosis scale inhibitor for high-silicon water, characterized in that: In terms of mass percentage, the raw materials include: 40-65wt% of polyaminopolyether methylenephosphonic acid, 5-18wt% of 2-hydroxyphosphonoacetic acid, 2-15wt% of 2-phosphoryl-1,2,4-tricarboxylic acid butane, 3-20wt% of polyepoxysuccinic acid, 2-30wt% of sulfonate copolymer and 1-30wt% of acrylic polymer.

2. The reverse osmosis scale inhibitor for high-silicon water according to claim 1, characterized in that: In terms of mass percentage, the raw materials include: 41-60wt% of polyaminopolyether methylenephosphonic acid, 9-17wt% of 2-hydroxyphosphonoacetic acid, 3-13wt% of 2-phosphoric acid-1,2,4-tricarboxylic acid butane, 4-16wt% of polyepoxysuccinic acid, 5-25wt% of sulfonate copolymer, and 2-23wt% of acrylic polymer.

3. The reverse osmosis scale inhibitor for high-silicon water according to claim 1, characterized in that: In terms of mass percentage, the raw materials include: 65wt% of polyaminopolyether methylenephosphonic acid, 6wt% of 2-hydroxyphosphonoacetic acid, 5wt% of 2-phosphoryl-1,2,4-tricarboxylic acid butane, 8wt% of polyepoxysuccinic acid, 9wt% of sulfonate copolymer, and 7wt% of acrylic polymer.

4. The reverse osmosis scale inhibitor for high-silicon water according to claim 1, characterized in that: The sulfonate copolymer is any one of acrylic acid-2-acrylamide-2-methylpropanesulfonic acid copolymer, acrylic acid-2-acrylamide-2-methylpropanesulfonic acid-hydroxypropyl acrylate terpolymer, acrylic acid-2-acrylamide-2-methylpropanesulfonic acid-ethyl acetoacetate terpolymer, and acrylic acid-acrylate-sulfonate terpolymer.

5. The reverse osmosis scale inhibitor for high-silicon water according to claim 1, characterized in that: The acrylic polymer is any one of polyacrylic acid, acrylic acid-acrylamide copolymer, acrylic acid-acrylic ester copolymer, acrylic acid-maleic anhydride copolymer, and acrylic acid-hydroxypropyl acrylate copolymer.

6. A method for preparing a reverse osmosis scale inhibitor for high-silicon water as claimed in any one of claims 1 to 5, characterized in that: The steps include: Polyaminopolyether methylenephosphonic acid, 2-hydroxyphosphonoacetic acid, 2-phospho-1,2,4-tricarboxylic acid butane, polyepoxysuccinic acid, sulfonate copolymer and acrylic polymer are added and mixed in sequence, and finally a special reverse osmosis scale inhibitor for high-silicon water quality is prepared.

7. The method for preparing the scale inhibitor according to claim 6, characterized in that: Stirring is performed during the mixing step, and the stirring time is 20-30 minutes.

8. The method for preparing the scale inhibitor according to claim 7, characterized in that: After stirring, it needs to be filtered and packaged, and then left to stand at room temperature.

9. The method for preparing the scale inhibitor according to claim 8, characterized in that: The standing time after the filtering and packaging process is 23-24 hours.

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