Preparation method and application of dye gel microspheres capable of efficiently adsorbing zwitterions
Multiple fold gel microspheres were prepared by combining materials of sodium alginate, octadecyl trimethylammonium chloride and dopamine hydrochloride. The problem of low adsorption efficiency of anion and cationic dyes in the prior art is solved by using electrostatic interactions. It achieves the effect of efficient adsorption of methylene blue and methyl orange, with simple process, low cost and easy to recover.
Patent Information
- Application Number
- CN202411380455.0
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2024-09-30
- Publication Date
- 2024-12-20
AI Technical Summary
The prior art is difficult to effectively remove wastewater containing anionic and cationic dyes, especially traditional adsorbents, with limited adsorption efficiency and difficult to efficiently treat both types of dyes at the same time.
Poly-wrinkled sodium alginate/polydopamine gel microspheres are prepared by materials such as sodium alginate, octadecyl trimethylammonium chloride and dopamine hydrochloride. Highly efficient gel microspheres are formed through Ca2+ cross-linking and H+ replacement. , , use electrostatic interaction to achieve efficient adsorption of anionic and cationic dyes.
The prepared gel microspheres can efficiently adsorb methylene blue and methyl orange, with the maximum adsorption amount reaching 730.96 mg/g and 667.91 mg/g respectively. The process is simple, low cost and easy to recycle, and are suitable for mass production.
Abstract
Description
Technical Field
[0001] The invention relates to the field of dye wastewater treatment, and in particular to a preparation method and application of gel microspheres capable of efficiently absorbing anionic and cationic dyes. Background Art
[0002] With the accelerated development of global urbanization and industrialization, water pollution is becoming increasingly serious, posing a great threat to human health and aquatic ecosystems. Wastewater contains difficult-to-treat organic matter, surfactants, additives and dyes. Among them, dyes are one of the key pollutants. Synthetic dyes are widely used in textile, papermaking, leather, pharmaceutical and other industries, causing a large amount of colored wastewater (Tkaczyk A, Mitrowska K, Posyniak A, Science of the Total Environment, 2020, 717: 137222). Synthetic dye molecules are difficult to biodegrade and have high toxicity, carcinogenicity, mutagenicity and sensitization. Compared with anionic dyes, cationic dyes can bind to the cell membrane surface and even enter the cell, which is more toxic. Methylene blue MB is a typical cationic dye with a wide range of applications. However, MB has a complex aromatic structure, is not easy to fade, and is prone to persistent toxicity. The aromatic ring structure and double bond structure in the molecular structure of the anionic dye methyl orange MO are the main parts of degradation. Among various methods such as coagulation / flocculation, chemical precipitation, reverse osmosis, ultrafiltration, oxidation, electrochemical method, biological method, etc., adsorption is considered to be a promising technology for wastewater treatment due to its low cost, convenient operation and strong versatility (Feng CT, Ren PG, Huo MX, Dai Z, Liang D, Jin YL, Ren F. Carbohydrate Polymers, 2020, 241:116369). Although traditional adsorbents (such as activated carbon and zeolite) have been widely used to remove pollutants from sewage, their adsorption efficiency is limited, especially when treating dye wastewater.
[0003] Biodegradable polymer hydrogels are favored by researchers because of their good regeneration adsorption capacity and low cost (Kubra KT, Salman MS, Znad H, Hasan M N. Journal of Molecular Liquids, 2021, 329: 115541). Biomacromolecule materials have attracted widespread attention due to their degradability, non-toxicity and biocompatibility. Sodium alginate SA is a natural biomacromolecule with a wide range of sources, low price, and green and harmless raw materials, and has broad application prospects. Through the chemical crosslinking of aminated lignin with epichlorohydrin and SA with Ca 2+By ionic crosslinking, LN-NH-SA hydrogel for dye adsorption was prepared, and the maximum adsorption capacity of methylene blue was 388.81 mg / g (Wang C, Feng XZ, Shang SB, Liu H, Song ZQ, Zhang HB, International Journal of Biological Macromolecules, 2023, 237: 124200). Sodium alginate SA / polyvinyl alcohol PVA composite nanofiber membrane was prepared by electrospinning. The adsorption capacity of the optimized nanofiber membrane for methylene blue MB, basic fuchsin BF and methyl orange MO was 9.25 mg / g, 9.02 mg / g and 7.35 mg / g, respectively (Jiang XD, Sang CX, Wang JK, GuoJ, Textile Research Journal, 2022, 92: 3154). Magnetic chitosan / polyethyleneimine-encapsulated hydrophobic sodium alginate composite material MCPS can be used to simultaneously remove aqueous homologous ionic heavy metals and azo dyes, and has good adsorption performance for Cr 6+ 、MO、Cu 2+ The saturated adsorption capacities of 2,4-dimethyl-1-oxo-1-yl and 2,6-dimethyl-1-oxo-1-yl are 87.53, 66.41, 351.03 and 286.54 mg / g, respectively (Zeng XC, Zhang GH, Wen J, Li XL, Zhu JF, Wu Z, Chemosphere, 2023, 318: 137869). However, these methods can only adsorb one dye or the adsorption amount is low. Therefore, the present invention designs a sodium alginate gel microsphere with simple preparation process, low price, batch production, high repeatability, easy recovery, and strong adsorption capacity for both methylene blue and methyl orange dyes. Summary of the invention
[0004] The technical problem to be solved by the present invention is: how to provide a method for preparing gel microspheres with simple preparation process, low price, easy recycling and high adsorption capacity for both anionic and cationic dyes.
[0005] The technical scheme adopted by the present invention is: a method for preparing gel microspheres with high efficiency in adsorbing anionic and cationic dyes, wherein sodium alginate (SA), octadecyltrimethylammonium chloride (STAC), and dopamine hydrochloride (DA·HCl) are dissolved in deionized water to prepare a solution, the three solutions are mixed evenly, stirred to form a uniform mixed solution, and then dropped into CaCl 2The solution is cross-linked into spheres; the microspheres are taken out, washed repeatedly with deionized water, and then placed in a hydrochloric acid solution for H+ replacement. The replaced microspheres are washed repeatedly with deionized water, and then placed in an oven and dried at 40-50°C to constant weight to obtain gel microspheres (SA@PDA-H), i.e., gel microspheres with high efficiency in adsorbing anionic and cationic dyes.
[0006] The mass percentage concentration of the sodium alginate solution is 1-4%, the mass percentage concentration of the octadecyltrimethylammonium chloride solution is 1-4%, and the mass percentage concentration of the dopamine hydrochloride solution is 1-4%. The three solutions are mixed at a mass ratio of 5:1:1 and stirred to form a uniform mixed solution.
[0007] After stirring to form a uniform mixed solution, let it stand to degas, and slowly drip it into a solution with a mass percentage concentration of 3% CaCl 2 The solution was allowed to stand for 24 h for cross-linking and curing.
[0008] When H+ replacement is performed, the concentration of the hydrochloric acid solution is 0.05 mol / L HCl, and the H+ replacement process is to stir at a constant speed for 2 h to carry out H+ replacement. + Replacement; The invention discloses an application of gel microspheres for efficiently absorbing anionic and cationic dyes, and an application of a high-efficiency gel microsphere adsorbent in treating wastewater containing anionic and cationic dyes.
[0009] The cationic dye is methylene blue, and the anionic dye is methyl orange.
[0010] The beneficial effects of the present invention are as follows: (1) the biocompatible polysaccharide sodium alginate (SA) carrying a large amount of anions and the protonated cationic polydopamine (PDA) in the Ca 2+ In the presence of water, the gel microspheres are cross-linked into three-dimensional network gel microspheres, so that the gel microspheres carry anions and cations at the same time, and can form electrostatic interactions with cationic and anionic dyes respectively. (2) The multi-fold sodium alginate / polydopamine gel microspheres (SA@PDA-H) are prepared by replacing octadecyltrimethylammonium chloride in the gel microspheres with hydrochloric acid. The average particle size of the gel microspheres prepared by this method is 0.9~1.1 mm, which can efficiently adsorb cationic and anionic dyes. The maximum adsorption capacity of methylene blue reaches 730.96 mg / g, the minimum adsorption capacity of methylene blue reaches 431.93 mg / g, the maximum adsorption capacity of methyl orange reaches 667.91 mg / g, and the minimum adsorption capacity of methyl orange reaches 168.99 mg / g. (3) The preparation process of the present invention is simple, the raw material source is widely available, the production cost is low, the operability is strong, it is easy to control, and the material is easy to recycle after use. It has good application prospects in the field of anionic and cationic dye wastewater treatment. DETAILED DESCRIPTION
[0011] Example 1: Prepare 3% sodium alginate, 1% octadecyltrimethylammonium chloride, and 3% dopamine hydrochloride solutions respectively, and then mix the three solutions at a mass ratio of 5:1:1 and stir at a constant temperature until a uniform mixed solution is formed. The mixed solution needs to be allowed to stand to degas, and then a syringe with a needle is used to extract the mixed solution, and then a 3% CaCl 2 The prepared microspheres were rinsed with deionized water for 2-3 times, the surface of the microspheres were wiped with filter paper, and then the microspheres were placed in a 0.05 mol / L hydrochloric acid solution and stirred at a constant speed for 2 h. + Replacement. Rinse the replaced microspheres 2-3 times with deionized water, wipe the surface of the microspheres with filter paper, and dry them in an oven until the microspheres have a constant weight. + Replaced microspheres SA@PDA-H. 0.02 g SA@PDA-H microspheres were accurately weighed and placed in two conical flasks, and 20 mL of methylene blue and methyl orange solutions with an initial concentration of 800 mg / L, pH of 7.0, and salinity of 0 were added. The solution was placed in a constant temperature oscillator and oscillated at 25°C. The saturated adsorption amounts reached 730.96 mg / g and 667.91 mg / g, respectively.
[0012] Example 2: Prepare 1% sodium alginate, 2% octadecyltrimethylammonium chloride, and 3% dopamine hydrochloride solutions respectively, and then mix the three solutions at a mass ratio of 5:1:1 and stir at a constant temperature until a uniform mixed solution is formed. The mixed solution needs to be allowed to stand to degas, and then a syringe with a needle is used to extract the mixed solution, and then a 3% CaCl 2 The prepared microspheres were rinsed with deionized water for 2-3 times, the surface of the microspheres were wiped with filter paper, and then the microspheres were placed in a 0.05 mol / L hydrochloric acid solution and stirred at a constant speed for 2 h. + Replacement. Rinse the replaced microspheres 2-3 times with deionized water, wipe the surface of the microspheres with filter paper, and dry them in an oven until the microspheres have a constant weight. + Replaced microspheres SA@PDA-H. Weigh 0.02 g of microspheres SA@PDA-H accurately in a conical flask, add 20 mL of methylene blue and methyl orange solutions with an initial concentration of 800 mg / L, pH 7.0, and salinity of 0, place in a constant temperature oscillator, oscillate at 25°C, and the saturated adsorption amounts can reach 519.44 mg / g and 473.94 mg / g, respectively.
[0013] Example 3: Prepare 2% sodium alginate, 2% octadecyltrimethylammonium chloride, and 3% dopamine hydrochloride solutions respectively, and then mix the three solutions at a mass ratio of 5:1:1 and stir at a constant temperature until a uniform mixed solution is formed. The mixed solution needs to be allowed to stand to degas, and then a syringe with a needle is used to extract the mixed solution, and then a 3% CaCl 2 The prepared microspheres were rinsed with deionized water for 2-3 times, the surface of the microspheres were wiped with filter paper, and then the microspheres were placed in a 0.05 mol / L hydrochloric acid solution and stirred at a constant speed for 2 h. + Replacement. Rinse the replaced microspheres 2-3 times with deionized water, wipe the surface of the microspheres with filter paper, and dry them in an oven until the microspheres have a constant weight. + Replaced microspheres SA@PDA-H. 0.02 g of microspheres SA@PDA-H were accurately weighed in a conical flask, and 20 mL of methylene blue and methyl orange solutions with an initial concentration of 800 mg / L, pH of 7.0, and salinity of 0 were added. The solution was placed in a constant temperature oscillator and oscillated at 25°C. The saturated adsorption capacity reached 473.27 mg / g and 269.27 mg / g, respectively.
[0014] Example 4: Prepare 4% sodium alginate, 2% octadecyltrimethylammonium chloride, and 3% dopamine hydrochloride solutions respectively, and then mix the three solutions at a mass ratio of 5:1:1 and stir at a constant temperature until a uniform mixed solution is formed. The mixed solution needs to be allowed to stand to degas, and then the mixed solution is extracted with a syringe with a needle and slowly and uniformly dripped into 3% CaCl 2 The prepared microspheres were rinsed with deionized water for 2-3 times, the surface of the microspheres were wiped with filter paper, and then the microspheres were placed in a 0.05 mol / L hydrochloric acid solution and stirred at a constant speed for 2 h. + Replacement. Rinse the replaced microspheres 2-3 times with deionized water, wipe the surface of the microspheres with filter paper, and dry them in an oven until the microspheres have a constant weight. + Replaced microspheres SA@PDA-H. 0.02 g of microspheres SA@PDA-H were accurately weighed in a conical flask, and 20 mL of methylene blue and methyl orange solutions with an initial concentration of 800 mg / L, pH of 7.0, and salinity of 0% were added. The solution was placed in a constant temperature oscillator and oscillated at 25°C. The saturated adsorption capacity reached 431.93 mg / g and 339.66 mg / g, respectively.
[0015] Example 5: Prepare 3% sodium alginate, 3% octadecyltrimethylammonium chloride, and 3% dopamine hydrochloride solutions respectively, and then mix the three solutions at a mass ratio of 5:1:1 and stir at a constant temperature until a uniform mixed solution is formed. The mixed solution needs to be allowed to stand to degas, and then a syringe with a needle is used to extract the mixed solution, and then a 3% CaCl 2 The prepared microspheres were rinsed with deionized water for 2-3 times, the surface of the microspheres were wiped with filter paper, and then the microspheres were placed in a 0.05 mol / L hydrochloric acid solution and stirred at a constant speed for 2 h. + Replacement. Rinse the replaced microspheres 2-3 times with deionized water, wipe the surface of the microspheres with filter paper, and dry them in an oven until the microspheres have a constant weight. + Replaced microspheres SA@PDA-H. Accurately weigh 0.02 g of microspheres SA@PDA-H in a conical flask, add 20 mL of methylene blue and methyl orange solutions with an initial concentration of 800 mg / L, pH of 7.0, and salinity of 0, place in a constant temperature oscillator, oscillate at 25°C, and the saturated adsorption amounts can reach 507.24 mg / g and 168.99 mg / g, respectively.
Claims
1. A method for preparing gel microspheres with high efficiency in adsorbing anionic and cationic dyes, characterized in that: Sodium alginate, octadecyltrimethylammonium chloride and dopamine hydrochloride are respectively dissolved in deionized water to prepare solutions, the three solutions are mixed evenly, stirred to form a uniform mixed solution, and then dropped into a CaCl2 solution to cross-link into spheres; The microspheres are taken out, washed repeatedly with deionized water, and then placed in a hydrochloric acid solution for H+ replacement. The replaced microspheres are washed repeatedly with deionized water, and then placed in an oven and dried at 40-50°C to constant weight to obtain gel microspheres, i.e., gel microspheres with high efficiency in adsorbing anionic and cationic dyes.
2. The method for preparing a highly efficient anionic and cationic dye adsorption gel microsphere according to claim 1, characterized in that: The mass percentage concentration of the sodium alginate solution is 1-4%, the mass percentage concentration of the octadecyltrimethylammonium chloride solution is 1-4%, and the mass percentage concentration of the dopamine hydrochloride solution is 1-4%. The three solutions are mixed at a mass ratio of 5:1:1 and stirred to form a uniform mixed solution.
3. The method for preparing a highly efficient adsorption of anionic and cationic dye gel microspheres according to claim 1, characterized in that: After stirring to form a uniform mixed solution, the mixture was allowed to stand to degas, and then slowly dripped into a 3% CaCl2 solution by mass percentage using a syringe, and allowed to stand for cross-linking and curing for 24 h.
4. The method for preparing a highly efficient anionic and cationic dye adsorption gel microsphere according to claim 1, characterized in that: When H+ replacement is performed, the concentration of the hydrochloric acid solution is 0.05 mol / L HCl, and the H+ replacement process is to stir at a constant speed for 2 h to carry out H+ replacement. + Replacement.
5. An application of gel microspheres with high efficiency in adsorbing anionic and cationic dyes prepared by the preparation method according to claims 1-4, characterized in that: Application of high-efficiency gel microsphere adsorbent in treating wastewater containing anionic and cationic dyes.
6. The use of a highly efficient adsorption of anionic and cationic dye gel microspheres according to claim 5, characterized in that: The cationic dye is methylene blue, and the anionic dye is methyl orange.