A reverse osmosis membrane antiscalant for high-speed rail and high-alumina wastewater treatment and its preparation method

Abstract

This invention relates to the field of scale inhibitor production technology, specifically to a reverse osmosis membrane scale inhibitor for high-iron and high-alumina wastewater treatment and its preparation method; it is used to solve the problems of poor scale inhibition performance and fouling deposition on the surface of reverse osmosis membranes by existing scale inhibitors; firstly, aminobutyric acid dihydroxyoxime acid and aminophenyl vinyl-8-hydroxyquinoline are synthesized, and the imine diacetic acid group of the chelating resin is reacted with the amino groups in aminobutyric acid dihydroxyoxime acid and aminophenyl vinyl-8-hydroxyquinoline respectively to obtain a double-modified chelating resin of isohydroxyoxime acid group and 8-hydroxyquinoline group. The isohydroxyoxime acid group forms a stable chelate with iron ions and aluminum ions through a hexadecimal octahedral complex structure, and the 8-hydroxyquinoline group forms a five-membered ring chelate with the nitrogen atom of the quinoline ring through the hydroxyl oxygen, which has the ability to chelate aluminum ions and iron ions, inhibiting the formation of fouling and organic deposits on the membrane surface and keeping the membrane surface clean.

Description

Technical Field

[0001] This invention relates to the field of scale inhibitor production technology, specifically to a reverse osmosis membrane scale inhibitor for high-iron and high-alumina wastewater treatment and its preparation method. Background Technology

[0002] Reverse osmosis technology is an effective water treatment method that can effectively remove suspended solids, dissolved salts, and organic matter from water. However, reverse osmosis membranes are susceptible to scaling and clogging caused by calcium, magnesium, and aluminum ions during use, leading to reduced treatment efficiency and increased maintenance costs. To overcome this problem, various water treatment agents have been developed, among which scale inhibitors are a key category. Scale inhibitors can form a protective layer on the surface of the reverse osmosis membrane, effectively inhibiting the precipitation of salts and metal ions, thereby maintaining the high flux and low energy consumption of the reverse osmosis membrane. However, existing scale inhibitors exhibit significant limitations in certain application scenarios, particularly in the treatment of high-speed rail and high-alumina wastewater. Many traditional scale inhibitors may be ineffective or even form deposits, exacerbating the scaling problem. Therefore, this invention provides a reverse osmosis membrane scale inhibitor for high-speed rail and high-alumina wastewater treatment and its preparation method, which inhibits scaling on the surface of the reverse osmosis membrane and increases the service life of the membrane element. Summary of the Invention

[0003] In order to overcome the above-mentioned technical problems, the present invention aims to provide a reverse osmosis membrane antiscalant for high-speed rail and high-alumina wastewater treatment and its preparation method, which solves the problems of poor antiscaling performance of existing antiscalants and fouling deposition on the surface of reverse osmosis membranes.

[0004] The objective of this invention can be achieved through the following technical solutions: In a first aspect, this application provides a reverse osmosis membrane antiscalant for high-speed rail and high-alumina wastewater treatment, comprising the following parts by weight: The mixture comprises 20-40 parts of a chelated resin modified with hydroxamic acid and 8-hydroxyquinoline, 10-20 parts of polyepoxysuccinic acid, 6-20 parts of sodium polystyrene sulfonate, 4-6 parts of benzisothiazolinone, 4-6 parts of dibromocyanoacetamide, 0.5-5 parts of 9,10-dihydroxystearic acid, 0.5-0.8 parts of triethanolamine, and 80 parts of deionized water. The isohydroxamic acid and 8-hydroxyquinoline dual-modified chelate resin is prepared by the following steps: Step A1: Add hydroxylamine hydrochloride, sodium hydroxide, and deionized water to a three-necked flask equipped with a thermometer and a stirrer, and react at 0°C for 2 hours. Add L-aspartic acid dimethyl ester hydrochloride, and react at 80°C for 4 hours. Cool, add dilute hydrochloric acid dropwise to adjust the pH to 3-4, stir for 30 minutes, filter under reduced pressure, wash the precipitate 3-5 times with distilled water, and place it in a drying oven to dry under vacuum at 40°C for 12 hours to obtain aminobutyric acid dihydroxyxamic acid. Step A2: Add 4-aminobenzaldehyde and acetic anhydride to a three-necked flask equipped with a stirrer and thermometer, purge with nitrogen for protection, stir for 30 min, add 2-methyl-8-hydroxyquinoline and stir at 125 °C for 40 h, cool and add to ice water and stir for 10-12 h, filter, place in a drying oven and dry at 60 °C for 8 h to obtain intermediate product 1; Step A3: Add intermediate product 1 and N,N-dimethylformamide to a three-necked flask equipped with a thermometer and a stirrer, stir for 10-15 min, heat to 120℃, add hydrochloric acid dropwise, react at 125℃ for 2 h, cool, filter, place in a drying oven and vacuum dry at 60℃ for 8 h to obtain intermediate product 2. Step A4: Add intermediate 2, N,N-dimethylformamide and triethylamine to a three-necked flask equipped with a thermometer and a stirrer, stir at 60°C for 1 h, cool and add to ice water and stir for 10-12 h, filter, and perform column chromatography with petroleum ether-ethyl acetate mixed solvent to obtain aminophenyl vinyl-8-hydroxyquinoline. Step A5: Add the chelating resin and tetrahydrofuran to a beaker, allow it to swell for 3 hours, filter and wash 2-3 times with deionized water, then add it to a three-necked flask equipped with a thermometer and stirrer. Add gamma-aminobutyric acid dihydroxyoxime, aminophenyl vinyl-8-hydroxyquinoline and N,N-dimethylformamide, place in an oil bath and react at 90°C for 4 hours. Cool, filter, wash 3-5 times with deionized water, and dry to obtain the isohydroxyoxime and 8-hydroxyquinoline dual-modified chelating resin.

[0005] As a further aspect of the present invention: the ratio of hydroxylamine hydrochloride, sodium hydroxide, deionized water and L-aspartic acid dimethyl ester hydrochloride in step A1 is 0.2-0.4 mol: 0.4-0.8 mol: 100-200 mL: 0.1-0.2 mol.

[0006] As a further aspect of the present invention: the mass fraction of the dilute hydrochloric acid in step A1 is 10%.

[0007] As a further aspect of the present invention: the ratio of 4-aminobenzaldehyde, acetic anhydride, 2-methyl-8-hydroxyquinoline and ice water in step A2 is 10-20 mmol: 30-60 mL: 6.3-12.6 mmol: 100-200 mL.

[0008] As a further aspect of the present invention: the ratio of intermediate product 1, N,N-dimethylformamide and hydrochloric acid in step A3 is 6-12 mmol: 35-70 mL: 35-70 mL.

[0009] As a further aspect of the present invention: the mass fraction of hydrochloric acid in step A3 is 36%.

[0010] As a further aspect of the present invention: the ratio of intermediate product 2, N,N-dimethylformamide, triethylamine and ice water in step A4 is 6-12 mmol: 35-70 mL: 15-30 mL: 100-200 mL.

[0011] As a further aspect of the present invention: the volume ratio of petroleum ether to ethyl acetate in the petroleum ether-ethyl acetate mixed solvent in step A4 is 3:1.

[0012] As a further aspect of the present invention: the ratio of the chelating resin, tetrahydrofuran, aminobutyric acid dihydroxyoxime, aminophenyl vinyl-8-hydroxyquinoline, and N,N-dimethylformamide used in step A5 is 10-20g: 50-100mL: 1.5-3g: 1-2g: 50-100mL.

[0013] As a further aspect of the present invention: the chelating resin mentioned in step A5 is of type D581.

[0014] Secondly, a method for preparing a reverse osmosis membrane antiscalant for treating high-speed rail and high-alumina wastewater includes the following steps: Step 1: Weigh out 20-40 parts by weight of the following: hydroxamic acid and 8-hydroxyquinoline dual-modified chelating resin, 10-20 parts of polyepoxysuccinic acid, 6-20 parts of sodium polystyrene sulfonate, 4-6 parts of benzisothiazolinone, 4-6 parts of dibromocyanoacetamide, 0.5-5 parts of 9,10-dihydroxystearic acid, 0.5-0.8 parts of triethanolamine, and 80 parts of deionized water. The polyepoxysuccinic acid has a molecular weight of 700-850 Daltons, and the sodium polystyrene sulfonate has a molecular weight of 50,000-100,000 Daltons. Step 2: Add isohydroxamic acid and 8-hydroxyquinoline dual-modified chelating resin, polyepoxysuccinic acid, sodium polystyrene sulfonate and deionized water to the reaction vessel, stir and mix, adjust the pH to 4-6, add benzisothiazolinone, dibromocyanoacetamide, 9,10-dihydroxystearic acid and triethanolamine and stir and mix to obtain a reverse osmosis membrane antiscalant for high iron and high aluminum wastewater treatment.

[0015] The beneficial effects of this invention are: This invention discloses a reverse osmosis membrane antiscalant for treating high-iron and high-alumina wastewater and its preparation method. It involves synthesizing aminobutyric acid dihydroxyoxime and aminophenyl vinyl-8-hydroxyquinoline, modifying the chelating resin, and specifically adsorbing scale ions in high-iron and high-alumina wastewater. This reduces the deposition rate of these ions on the reverse osmosis membrane surface, thereby extending the service life of the membrane element and improving the system's operating efficiency.

[0016] A reverse osmosis membrane antiscalant for treating high-iron and high-alumina wastewater was prepared. First, L-aspartic acid dimethyl ester hydrochloride reacted with hydroxylamine hydrochloride to obtain gamma-aminobutyric acid dihydroxyxamic acid. Then, 4-aminobenzaldehyde, 2-methyl-8-hydroxyquinoline, and acetic anhydride reacted to obtain intermediate 1. Intermediate 1 was then reacted with hydrochloric acid to obtain intermediate 2. Intermediate 2 was neutralized with triethylamine to remove the hydrochloric acid, yielding aminophenyl vinyl-8-hydroxyquinoline. The imine diacetic acid groups of the chelating resin reacted with gamma-aminobutyric acid dihydroxyxamic acid and aminophenyl vinyl-8-hydroxyquinoline, respectively. The amino groups in the porphyrin react to obtain a double-modified chelate resin of isohydroxamic acid and 8-hydroxyquinoline. The isohydroxamic acid group forms a highly stable chelate with iron and aluminum ions through a hexadecimal octahedral complex structure, effectively preventing the deposition of iron and aluminum ions on the membrane surface. The 8-hydroxyquinoline group forms a five-membered ring chelate with the nitrogen atom of the quinoline ring through the hydroxyl oxygen, which has a broad-spectrum chelating ability for aluminum and iron ions, avoiding their hydrolysis and precipitation. It can effectively prevent the formation of fouling on the reverse osmosis membrane surface when treating high-iron and high-aluminum wastewater, ensuring the membrane's permeability and long-term performance. Detailed Implementation

[0017] The technical solutions of the present invention will be clearly and completely described below with reference to the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention. Example 1:

[0018] This embodiment describes a method for preparing a reverse osmosis membrane antiscalant for treating high-speed rail and high-alumina wastewater, comprising the following steps: Step A1: Add 0.2 mol hydroxylamine hydrochloride, 0.4 mol sodium hydroxide and 100 mL deionized water to a three-necked flask equipped with a thermometer and a stirrer. React at 0 °C for 2 h. Add 0.1 mol L-aspartic acid dimethyl ester hydrochloride and react at 80 °C for 4 h. Cool and adjust the pH to 3 by adding dilute hydrochloric acid dropwise. Stir for 30 min, filter under reduced pressure, wash the precipitate three times with distilled water, and place it in a drying oven to dry under vacuum at 40 °C for 12 h to obtain dihydroxyoxime aminobutyric acid. Step A2: Add 10 mmol of 4-aminobenzaldehyde and 30 mL of acetic anhydride to a three-necked flask equipped with a stirrer and thermometer, purge with nitrogen for protection, stir for 30 min, add 6.3 mmol of 2-methyl-8-hydroxyquinoline and stir at 125 °C for 40 h, cool and add to 100 mL of ice water and stir for 10 h, filter, place in a drying oven and dry at 60 °C for 8 h to obtain intermediate product 1; Step A3: Add 6 mmol of intermediate product 1 and 35 mL of N,N-dimethylformamide to a three-necked flask equipped with a thermometer and a stirrer, stir for 10 min, heat to 120 °C, add 35 mL of hydrochloric acid dropwise, react at 125 °C for 2 h, cool, filter, and place in a drying oven to dry under vacuum at 60 °C for 8 h to obtain intermediate product 2. Step A4: Add 6 mmol of intermediate 2, 35 mL of N,N-dimethylformamide and 15 mL of triethylamine to a three-necked flask equipped with a thermometer and a stirrer. Stir at 60 °C for 1 h, cool and add to 100 mL of ice water and stir for 10 h. Filter and perform column chromatography with petroleum ether-ethyl acetate mixed solvent to obtain aminophenyl vinyl-8-hydroxyquinoline. Step A5: Add 10g of chelating resin and 50mL of tetrahydrofuran to a beaker, allow it to swell for 3 hours, filter and wash twice with deionized water, then add to a three-necked flask equipped with a thermometer and stirrer, add 1.5g of aminobutyric acid dihydroxyoxime acid, 1g of aminophenyl vinyl-8-hydroxyquinoline and 50mL of N,N-dimethylformamide, place in an oil bath and react at 90℃ for 4 hours, cool, filter, wash three times with deionized water, and dry to obtain a double-modified chelating resin of isohydroxyoxime acid and 8-hydroxyquinoline groups; Step A6: Weigh out 20 parts by weight of the chelated resin modified with isohydroxamic acid and 8-hydroxyquinoline, 10 parts by weight of polyepoxysuccinic acid, 6 parts by weight of sodium polystyrene sulfonate, 4 parts by weight of benzisothiazolinone, 4 parts by weight of dibromocyanoacetamide, 0.5 parts by weight of 9,10-dihydroxystearic acid, 0.5 parts by weight of triethanolamine, and 80 parts by weight of deionized water for later use; wherein, the molecular weight of the polyepoxysuccinic acid is 700-850 Daltons; and the molecular weight of the sodium polystyrene sulfonate is 50,000-100,000 Daltons; Step A7: Add isohydroxamic acid and 8-hydroxyquinoline dual-modified chelating resin, polyepoxysuccinic acid, sodium polystyrene sulfonate and deionized water to the reaction vessel, stir and mix, adjust the pH to 4, add benzisothiazolinone, dibromocyanoacetamide, 9,10-dihydroxystearic acid and triethanolamine and stir and mix to obtain a reverse osmosis membrane antiscalant for high iron and high aluminum wastewater treatment. Example 2:

[0019] This embodiment describes a method for preparing a reverse osmosis membrane antiscalant for treating high-speed rail and high-alumina wastewater, comprising the following steps: Step A1: Add 0.3 mol hydroxylamine hydrochloride, 0.6 mol sodium hydroxide and 150 mL deionized water to a three-necked flask equipped with a thermometer and a stirrer. React at 0 °C for 2 h. Add 0.15 mol L-aspartic acid dimethyl ester hydrochloride and react at 80 °C for 4 h. Cool and adjust the pH to 3 by adding dilute hydrochloric acid dropwise. Stir for 30 min, filter under reduced pressure, wash the precipitate 4 times with distilled water, and place it in a drying oven to dry under vacuum at 40 °C for 12 h to obtain dihydroxyoxime aminobutyric acid. Step A2: Add 15 mmol of 4-aminobenzaldehyde and 45 mL of acetic anhydride to a three-necked flask equipped with a stirrer and thermometer, purge with nitrogen for protection, stir for 30 min, add 9.45 mmol of 2-methyl-8-hydroxyquinoline, stir at 125 °C for 40 h, cool and add to 150 mL of ice water, stir for 11 h, filter, place in a drying oven and dry at 60 °C for 8 h to obtain intermediate product 1; Step A3: Add 9 mmol of intermediate product 1 and 52.5 mL of N,N-dimethylformamide to a three-necked flask equipped with a thermometer and a stirrer. Stir for 13 min, heat to 120 °C, add 52.5 mL of hydrochloric acid dropwise, react at 125 °C for 2 h, cool, filter, and place in a drying oven to dry under vacuum at 60 °C for 8 h to obtain intermediate product 2. Step A4: Add 9 mmol of intermediate 2, 52.5 mL of N,N-dimethylformamide and 22.5 mL of triethylamine to a three-necked flask equipped with a thermometer and a stirrer. Stir at 60 °C for 1 h, cool and add to 150 mL of ice water and stir for 10-12 h. Filter and perform column chromatography with petroleum ether-ethyl acetate mixed solvent to obtain aminophenyl vinyl-8-hydroxyquinoline. Step A5: Add 15g of chelating resin and 75mL of tetrahydrofuran to a beaker, allow it to swell for 3 hours, filter and wash three times with deionized water, then add it to a three-necked flask equipped with a thermometer and a stirrer. Add 2.25g of aminobutyric acid dihydroxyxamic acid, 1.5g of aminophenyl vinyl-8-hydroxyquinoline and 75mL of N,N-dimethylformamide, place in an oil bath and react at 90℃ for 4 hours. Cool, filter, wash four times with deionized water, and dry to obtain a double-modified chelating resin of isohydroxyxamic acid and 8-hydroxyquinoline groups. Step A6: Weigh out 30 parts by weight of the isohydroxamic acid and 8-hydroxyquinoline dual-modified chelating resin, 15 parts of polyepoxysuccinic acid, 13 parts of sodium polystyrene sulfonate, 5 parts of benzisothiazolinone, 5 parts of dibromocyanoacetamide, 2.75 parts of 9,10-dihydroxystearic acid, 0.65 parts of triethanolamine, and 80 parts of deionized water for later use; wherein, the molecular weight of the polyepoxysuccinic acid is 700-850 Daltons; and the molecular weight of the sodium polystyrene sulfonate is 50,000-100,000 Daltons; Step A7: Add the isohydroxamic acid and 8-hydroxyquinolino dual-modified chelating resin, polyepoxysuccinic acid, sodium polystyrene sulfonate and deionized water to the reaction vessel, stir and mix, adjust the pH to 5, add benzisothiazolinone, dibromocyanoacetamide, 9,10-dihydroxystearic acid and triethanolamine and stir and mix to obtain the reverse osmosis membrane antiscalant for high iron and high aluminum wastewater treatment. Example 3:

[0020] This embodiment describes a method for preparing a reverse osmosis membrane antiscalant for treating high-speed rail and high-alumina wastewater, comprising the following steps: Step A1: Add 0.4 mol hydroxylamine hydrochloride, 0.8 mol sodium hydroxide and 200 mL deionized water to a three-necked flask equipped with a thermometer and a stirrer. React at 0 °C for 2 h. Add 0.2 mol L-aspartic acid dimethyl ester hydrochloride and react at 80 °C for 4 h. Cool and adjust the pH to 4 by adding dilute hydrochloric acid dropwise. Stir for 30 min, filter under reduced pressure, wash the precipitate 5 times with distilled water, and place it in a drying oven to dry under vacuum at 40 °C for 12 h to obtain aminobutyric acid dihydroxyoxime. Step A2: Add 20 mmol of 4-aminobenzaldehyde and 60 mL of acetic anhydride to a three-necked flask equipped with a stirrer and thermometer, purge with nitrogen for protection, stir for 30 min, add 12.6 mmol of 2-methyl-8-hydroxyquinoline, stir at 125 °C for 40 h, cool and add to 200 mL of ice water, stir for 12 h, filter, place in a drying oven and dry at 60 °C for 8 h to obtain intermediate product 1; Step A3: Add 12 mmol of intermediate product 1 and 70 mL of N,N-dimethylformamide to a three-necked flask equipped with a thermometer and a stirrer, stir for 15 min, heat to 120 °C, add 70 mL of hydrochloric acid dropwise, react at 125 °C for 2 h, cool, filter, and place in a drying oven to dry under vacuum at 60 °C for 8 h to obtain intermediate product 2. Step A4: 12 mmol of intermediate 2, 70 mL of N,N-dimethylformamide and 30 mL of triethylamine were added to a three-necked flask equipped with a thermometer and a stirrer. The mixture was stirred at 60 °C for 1 h, cooled and added to 200 mL of ice water and stirred for 12 h. The mixture was filtered and subjected to column chromatography with a petroleum ether-ethyl acetate mixed solvent to obtain aminophenyl vinyl-8-hydroxyquinoline. Step A5: Add 20g of chelating resin and 100mL of tetrahydrofuran to a beaker, allow it to swell for 3 hours, filter and wash 3 times with deionized water, add to a three-necked flask equipped with a thermometer and stirrer, add 3g of aminobutyric acid dihydroxyoxime acid, 2g of aminophenyl vinyl-8-hydroxyquinoline and 100mL of N,N-dimethylformamide, place in an oil bath and react at 90℃ for 4 hours, cool, filter, wash 5 times with deionized water, dry, and obtain the isohydroxyoxime acid and 8-hydroxyquinoline dual-modified chelating resin; Step A6: Weigh out 40 parts by weight of the hydroxamic acid and 8-hydroxyquinoline dual-modified chelating resin, 20 parts of polyepoxysuccinic acid, 20 parts of sodium polystyrene sulfonate, 6 parts of benzisothiazolinone, 6 parts of dibromocyanoacetamide, 5 parts of 9,10-dihydroxystearic acid, 0.8 parts of triethanolamine, and 80 parts of deionized water for later use; wherein, the molecular weight of the polyepoxysuccinic acid is 700-850 Daltons; and the molecular weight of the sodium polystyrene sulfonate is 50,000-100,000 Daltons; Step A7: Add isohydroxamic acid and 8-hydroxyquinolino dual-modified chelating resin, polyepoxysuccinic acid, sodium polystyrene sulfonate and deionized water to the reaction vessel, stir and mix, adjust the pH to 6, add benzisothiazolinone, dibromocyanoacetamide, 9,10-dihydroxystearic acid and triethanolamine and stir and mix to obtain a reverse osmosis membrane antiscalant for high iron and high aluminum wastewater treatment.

[0021] Comparative Example 1: This comparative example illustrates a method for preparing a reverse osmosis membrane antiscalant for treating high-speed rail and high-alumina wastewater, comprising the following steps: Step A1: Add 0.4 mol hydroxylamine hydrochloride, 0.8 mol sodium hydroxide and 200 mL deionized water to a three-necked flask equipped with a thermometer and a stirrer. React at 0 °C for 2 h. Add 0.2 mol L-aspartic acid dimethyl ester hydrochloride and react at 80 °C for 4 h. Cool and adjust the pH to 4 by adding dilute hydrochloric acid dropwise. Stir for 30 min, filter under reduced pressure, wash the precipitate 5 times with distilled water, and place it in a drying oven to dry under vacuum at 40 °C for 12 h to obtain aminobutyric acid dihydroxyoxime. Step A2: Add 20g of chelating resin and 100mL of tetrahydrofuran to a beaker, allow it to swell for 3 hours, filter and wash 3 times with deionized water, add to a three-necked flask equipped with a thermometer and stirrer, add 3g of aminobutyric acid dihydroxamic acid and 100mL of N,N-dimethylformamide, place in an oil bath and react at 90℃ for 4 hours, cool, filter, wash 5 times with deionized water, and dry to obtain isohydroxamic acid-modified chelating resin; Step A3: Weigh out 40 parts by weight of isohydroxamic acid-modified chelating resin, 20 parts of polyepoxysuccinic acid, 20 parts of sodium polystyrene sulfonate, 6 parts of benzisothiazolinone, 6 parts of dibromocyanoacetamide, 5 parts of 9,10-dihydroxystearic acid, 0.8 parts of triethanolamine, and 80 parts of deionized water for later use; wherein, the molecular weight of the polyepoxysuccinic acid is 700-850 Daltons; and the molecular weight of the sodium polystyrene sulfonate is 50,000-100,000 Daltons; Step A4: Add isohydroxamic acid-modified chelating resin, polyepoxysuccinic acid, sodium polystyrene sulfonate and deionized water to the reaction vessel, stir and mix, adjust the pH to 6, add benzisothiazolinone, dibromocyanoacetamide, 9,10-dihydroxystearic acid and triethanolamine and stir and mix to obtain a reverse osmosis membrane antiscalant for high iron and high aluminum wastewater treatment.

[0022] Comparative Example 2: This comparative example illustrates a method for preparing a reverse osmosis membrane antiscalant for treating high-speed rail and high-alumina wastewater, comprising the following steps: Step A1: Add 20 mmol of 4-aminobenzaldehyde and 60 mL of acetic anhydride to a three-necked flask equipped with a stirrer and thermometer, purge with nitrogen for protection, stir for 30 min, add 12.6 mmol of 2-methyl-8-hydroxyquinoline, stir at 125 °C for 40 h, cool and add to 200 mL of ice water, stir for 12 h, filter, place in a drying oven and dry at 60 °C for 8 h to obtain intermediate product 1; Step A2: Add 12 mmol of intermediate product 1 and 70 mL of N,N-dimethylformamide to a three-necked flask equipped with a thermometer and a stirrer, stir for 15 min, heat to 120 °C, add 70 mL of hydrochloric acid dropwise, react at 125 °C for 2 h, cool, filter, and place in a drying oven to dry under vacuum at 60 °C for 8 h to obtain intermediate product 2. Step A3: 12 mmol of intermediate 2, 70 mL of N,N-dimethylformamide and 30 mL of triethylamine were added to a three-necked flask equipped with a thermometer and a stirrer. The mixture was stirred at 60 °C for 1 h, cooled and added to 200 mL of ice water and stirred for 12 h. The mixture was filtered and subjected to column chromatography with a petroleum ether-ethyl acetate mixed solvent to obtain aminophenyl vinyl-8-hydroxyquinoline. Step A4: Add 20g of chelating resin and 100mL of tetrahydrofuran to a beaker, allow it to swell for 3 hours, filter and wash 3 times with deionized water, add to a three-necked flask equipped with a thermometer and stirrer, add 2g of aminophenyl vinyl-8-hydroxyquinoline and 100mL of N,N-dimethylformamide, place in an oil bath and react at 90℃ for 4 hours, cool, filter, wash 5 times with deionized water, and dry to obtain 8-hydroxyquinoline-modified chelating resin; Step A5: Weigh out 40 parts by weight of 8-hydroxyquinoline-modified chelating resin, 20 parts of polyepoxysuccinic acid, 20 parts of sodium polystyrene sulfonate, 6 parts of benzisothiazolinone, 6 parts of dibromocyanoacetamide, 5 parts of 9,10-dihydroxystearic acid, 0.8 parts of triethanolamine, and 80 parts of deionized water for later use; wherein, the molecular weight of the polyepoxysuccinic acid is 700-850 Daltons; and the molecular weight of the sodium polystyrene sulfonate is 50,000-100,000 Daltons; Step A6: Add 8-hydroxyquinoline-modified chelating resin, polyepoxysuccinic acid, sodium polystyrene sulfonate, and deionized water to the reaction vessel, stir and mix, adjust the pH to 6, add benzisothiazolinone, dibromocyanoacetamide, 9,10-dihydroxystearic acid, and triethanolamine, and stir and mix to obtain a reverse osmosis membrane antiscalant for high-iron and high-alumina wastewater treatment.

[0023] Comparative Example 3: This comparative example illustrates a method for preparing a reverse osmosis membrane antiscalant for treating high-speed rail and high-alumina wastewater, comprising the following steps: Step A1: Add 0.4 mol hydroxylamine hydrochloride, 0.8 mol sodium hydroxide and 200 mL deionized water to a three-necked flask equipped with a thermometer and a stirrer. React at 0 °C for 2 h. Add 0.2 mol L-aspartic acid dimethyl ester hydrochloride and react at 80 °C for 4 h. Cool and adjust the pH to 4 by adding dilute hydrochloric acid dropwise. Stir for 30 min, filter under reduced pressure, wash the precipitate 5 times with distilled water, and place it in a drying oven to dry under vacuum at 40 °C for 12 h to obtain aminobutyric acid dihydroxyoxime. Step A2: Weigh out 40 parts by weight of D581 chelating resin, 20 parts of polyepoxysuccinic acid, 20 parts of sodium polystyrene sulfonate, 5 parts of aminobutyric acid dihydroxyoxime acid, 6 parts of benzisothiazolinone, 6 parts of dibromocyanoacetamide, 5 parts of 9,10-dihydroxystearic acid, 0.8 parts of triethanolamine, and 80 parts of deionized water for later use; wherein, the molecular weight of the polyepoxysuccinic acid is 700-850 Daltons; and the molecular weight of the sodium polystyrene sulfonate is 50,000-100,000 Daltons; Step A3: Add D581 chelating resin, polyepoxysuccinic acid, sodium polystyrene sulfonate and deionized water to the reaction vessel, stir and mix, adjust the pH to 6, add aminobutyric acid dihydroxyoxime acid, benzisothiazolinone, dibromocyanoacetamide, 9,10-dihydroxystearic acid and triethanolamine and stir and mix to obtain a reverse osmosis membrane antiscalant for high iron and high aluminum wastewater treatment.

[0024] Comparative Example 4: This comparative example illustrates a method for preparing a reverse osmosis membrane antiscalant for treating high-speed rail and high-alumina wastewater, comprising the following steps: Step A1: Add 20 mmol of 4-aminobenzaldehyde and 60 mL of acetic anhydride to a three-necked flask equipped with a stirrer and thermometer, purge with nitrogen for protection, stir for 30 min, add 12.6 mmol of 2-methyl-8-hydroxyquinoline, stir at 125 °C for 40 h, cool and add to 200 mL of ice water, stir for 12 h, filter, place in a drying oven and dry at 60 °C for 8 h to obtain intermediate product 1; Step A2: Add 12 mmol of intermediate product 1 and 70 mL of N,N-dimethylformamide to a three-necked flask equipped with a thermometer and a stirrer, stir for 15 min, heat to 120 °C, add 70 mL of hydrochloric acid dropwise, react at 125 °C for 2 h, cool, filter, and place in a drying oven to dry under vacuum at 60 °C for 8 h to obtain intermediate product 2. Step A3: 12 mmol of intermediate 2, 70 mL of N,N-dimethylformamide and 30 mL of triethylamine were added to a three-necked flask equipped with a thermometer and a stirrer. The mixture was stirred at 60 °C for 1 h, cooled and added to 200 mL of ice water and stirred for 12 h. The mixture was filtered and subjected to column chromatography with a petroleum ether-ethyl acetate mixed solvent to obtain aminophenyl vinyl-8-hydroxyquinoline. Step A4: Weigh out 40 parts by weight of D581 chelating resin, 20 parts by weight of polyepoxysuccinic acid, 20 parts by weight of sodium polystyrene sulfonate, 5 parts by weight of aminophenylvinyl-8-hydroxyquinoline, 6 parts by weight of benzisothiazolinone, 6 parts by weight of dibromocyanoacetamide, 5 parts by weight of 9,10-dihydroxystearic acid, 0.8 parts by weight of triethanolamine, and 80 parts by weight of deionized water for later use; wherein, the molecular weight of the polyepoxysuccinic acid is 700-850 Daltons; and the molecular weight of the sodium polystyrene sulfonate is 50,000-100,000 Daltons; Step A5: Add D581 chelating resin, polyepoxysuccinic acid, sodium polystyrene sulfonate and deionized water to the reaction vessel, stir and mix, adjust the pH to 6, add aminophenyl vinyl-8-hydroxyquinoline, benzisothiazolinone, dibromocyanoacetamide, 9,10-dihydroxystearic acid and triethanolamine and stir and mix to obtain a reverse osmosis membrane antiscalant for high iron and high aluminum wastewater treatment.

[0025] Performance testing: Examples 1-3 and Comparative Examples 1-4 were tested according to GB / T 16632-2019 "Determination of Scale Inhibition Performance of Water Treatment Agents - Calcium Carbonate Deposition Method" to determine the calcium carbonate scale inhibition rate of the reverse osmosis membrane antiscalant. Examples 1-3 and Comparative Examples 1-4 were tested according to GB / T 22626-2008 "Determination of Scale Inhibition Performance of Water Treatment Agents - Calcium Phosphate Deposition Method" to determine the calcium phosphate scale inhibition rate of the reverse osmosis membrane scale inhibitor. At room temperature, take 1g of each sample and add them separately to containers containing... The iron in the solution was placed in a beaker containing a sulfuric acid solution with a mass concentration of 1.5 g / L; after sealing, it was placed on a shaker and shaken for 2 days for adsorption; then the flask was removed, and the mass concentration of iron in the solution after adsorption was analyzed by flame atomic absorption spectrophotometry, and the adsorption amount was calculated.

[0026] Mix 1g of sample with 10mL of aluminum ion solution with a mass concentration of 1.5g / L, place in a 25℃ constant temperature water bath shaker and shake for 120min, filter and measure the aluminum ion concentration in the solution, and calculate the adsorption amount.

[0027] Referring to the table above, based on the comparison between Examples 1-3 and Comparative Examples 1-4, it can be seen that the reverse osmosis membrane antiscalant with added hydroxamic acid and 8-hydroxyquinoline dual-modified chelating resin has excellent antiscaling performance. Based on the comparison between Example 3 and Comparative Example 1, it can be seen that the reverse osmosis membrane antiscalant with the addition of isohydroxamic acid and 8-hydroxyquinoline dual-modified chelate resin has a higher calcium carbonate scale inhibition rate than the reverse osmosis membrane antiscalant with the addition of isohydroxamic acid modified chelate resin. This indicates that the reverse osmosis membrane antiscalant with the addition of isohydroxamic acid and 8-hydroxyquinoline dual-modified chelate resin has excellent scale inhibition performance. Based on the comparison between Example 3 and Comparative Example 2, it can be seen that the reverse osmosis membrane antiscalant with the addition of isohydroxamic acid and 8-hydroxyquinoline dual-modified chelating resin has a higher calcium carbonate scale inhibition rate than the reverse osmosis membrane antiscalant with the addition of 8-hydroxyquinoline dual-modified chelating resin. This indicates that the reverse osmosis membrane antiscalant with the addition of isohydroxamic acid and 8-hydroxyquinoline dual-modified chelating resin has excellent scale inhibition performance. Based on the comparison between Example 3 and Comparative Example 3, it can be seen that the reverse osmosis membrane antiscalant with the addition of isohydroxamic acid and 8-hydroxyquinoline dual-modified chelating resin has a higher calcium carbonate scale inhibition rate than the reverse osmosis membrane antiscalant with the addition of D581 chelating resin and aminobutyric acid dihydroxamic acid. This indicates that the reverse osmosis membrane antiscalant with the addition of isohydroxamic acid and 8-hydroxyquinoline dual-modified chelating resin has excellent scale inhibition performance. Based on the comparison between Example 3 and Comparative Example 4, it can be seen that the reverse osmosis membrane antiscalant with the addition of isohydroxamic acid and 8-hydroxyquinoline dual-modified chelating resin has a higher calcium carbonate scale inhibition rate than the reverse osmosis membrane antiscalant with the addition of D581 chelating resin and aminophenyl vinyl-8-hydroxyquinoline. This indicates that the reverse osmosis membrane antiscalant with the addition of isohydroxamic acid and 8-hydroxyquinoline dual-modified chelating resin has excellent scale inhibition performance.

[0028] In the description of this specification, references to terms such as "an embodiment," "example," "specific example," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the invention. In this specification, illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0029] The above description is merely an example and illustration of the present invention. Those skilled in the art can make various modifications or additions to the specific embodiments described or use similar methods to replace them, as long as they do not deviate from the invention or exceed the scope defined in this application, they should all fall within the protection scope of the present invention.

Claims

1. A reverse osmosis membrane antiscalant for treating high-alumina wastewater from high-speed rail, characterized in that, Includes the following components by weight: The mixture comprises 20-40 parts of a chelated resin modified with hydroxamic acid and 8-hydroxyquinoline, 10-20 parts of polyepoxysuccinic acid, 6-20 parts of sodium polystyrene sulfonate, 4-6 parts of benzisothiazolinone, 4-6 parts of dibromocyanoacetamide, 0.5-5 parts of 9,10-dihydroxystearic acid, 0.5-0.8 parts of triethanolamine, and 80 parts of deionized water. The isohydroxamic acid and 8-hydroxyquinoline dual-modified chelate resin is prepared by the following steps: Step A1: React hydroxylamine hydrochloride, sodium hydroxide and deionized water, add L-aspartic acid dimethyl ester hydrochloride and react, cool, adjust pH, stir, filter under reduced pressure, wash and dry to obtain aminobutyric acid dihydroxyxamic acid; Step A2: Stir 4-aminobenzaldehyde and acetic anhydride, add 2-methyl-8-hydroxyquinoline and stir, cool and add to ice water and stir, filter, dry to obtain intermediate product 1; Step A3: Stir intermediate 1 and N,N-dimethylformamide, heat, add hydrochloric acid, react, cool, filter, and dry to obtain intermediate 2; Step A4: Stir intermediate 2, N,N-dimethylformamide and triethylamine, cool and add to ice water and stir, filter, and column chromatography to obtain aminophenyl vinyl-8-hydroxyquinoline; Step A5: Swell the chelating resin and tetrahydrofuran, filter and wash, add to a flask, add aminobutyric acid dihydroxyoxime, aminophenyl vinyl-8-hydroxyquinoline and N,N-dimethylformamide, react in an oil bath, cool, filter, wash and dry to obtain the isohydroxyoxime and 8-hydroxyquinoline dual-modified chelating resin.

2. The scale inhibitor for reverse osmosis membranes used in high-speed rail and high-alumina wastewater treatment according to claim 1, characterized in that, The ratio of hydroxylamine hydrochloride, sodium hydroxide, deionized water, and L-aspartic acid dimethyl ester hydrochloride in step A1 is 0.2-0.4 mol: 0.4-0.8 mol: 100-200 mL: 0.1-0.2 mol.

3. The reverse osmosis membrane antiscalant for high-speed rail and high-alumina wastewater treatment according to claim 1, characterized in that, The ratio of 4-aminobenzaldehyde, acetic anhydride, 2-methyl-8-hydroxyquinoline and ice water in step A2 is 10-20 mmol: 30-60 mL: 6.3-12.6 mmol: 100-200 mL.

4. The scale inhibitor for reverse osmosis membranes used in high-speed rail and high-alumina wastewater treatment according to claim 1, characterized in that, In step A3, the ratio of intermediate 1, N,N-dimethylformamide, and hydrochloric acid is 6-12 mmol: 35-70 mL: 35-70 mL; the mass fraction of the hydrochloric acid is 36%.

5. The scale inhibitor for reverse osmosis membranes used in high-speed rail and high-alumina wastewater treatment according to claim 1, characterized in that, The ratio of intermediate product 2, N,N-dimethylformamide, triethylamine and ice water in step A4 is 6-12 mmol: 35-70 mL: 15-30 mL: 100-200 mL.

6. The reverse osmosis membrane antiscalant for high-speed rail and high-alumina wastewater treatment according to claim 1, characterized in that, In step A5, the ratio of the chelating resin, tetrahydrofuran, aminobutyric acid dihydroxyoxime, aminophenyl vinyl-8-hydroxyquinoline, and N,N-dimethylformamide is 10-20g: 50-100mL: 1.5-3g: 1-2g: 50-100mL; the type of the chelating resin is D581.

7. A method for preparing a reverse osmosis membrane antiscalant for high-speed rail and high-alumina wastewater treatment, characterized in that, The preparation of the reverse osmosis membrane antiscalant for high-iron and high-alumina wastewater treatment as described in any one of claims 1-6 includes the following steps: Step 1: Weigh out 20-40 parts by weight of the following: hydroxamic acid and 8-hydroxyquinoline dual-modified chelating resin, 10-20 parts of polyepoxysuccinic acid, 6-20 parts of sodium polystyrene sulfonate, 4-6 parts of benzisothiazolinone, 4-6 parts of dibromocyanoacetamide, 0.5-5 parts of 9,10-dihydroxystearic acid, 0.5-0.8 parts of triethanolamine, and 80 parts of deionized water. The polyepoxysuccinic acid has a molecular weight of 700-850 Daltons, and the sodium polystyrene sulfonate has a molecular weight of 50,000-100,000 Daltons. Step 2: Add isohydroxamic acid and 8-hydroxyquinoline dual-modified chelating resin, polyepoxysuccinic acid, sodium polystyrene sulfonate and deionized water to the reaction vessel, stir and mix, adjust the pH to 4-6, add benzisothiazolinone, dibromocyanoacetamide, 9,10-dihydroxystearic acid and triethanolamine and stir and mix to obtain a reverse osmosis membrane antiscalant for high iron and high aluminum wastewater treatment.

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