Application of benzyltributyldiglycol eutectic solvent-salt solution aqueous two-phase system in alizarin yellow dye extraction

Abstract

The invention particularly relates to application of a benzyltributyldiglycol eutectic solvent-salt solution aqueous two-phase system in extraction of alizarin yellow dye, and belongs to the technical field of eutectic solvents. The method comprises the following steps: putting a benzyltributyldiglycol eutectic solvent-salt solution aqueous two-phase system into an aqueous solution containing alizarin yellow, and separating the alizarin yellow dye under a constant-temperature stirring condition; the benzyl tributyl diethylene glycol eutectic solvent is synthesized from benzyl tributyl ammonium chloride and diethylene glycol. The eutecticevaporate solvent-salt solution aqueous two-phase system prepared by the preparation method disclosed by the invention has relatively strong trapping capability on alizarin yellow dye; meanwhile, the benzyl tributyl diethylene glycol eutectic solvent has the advantages of being simple in synthesis, low in price and the like. Under the condition that the mass ratio of the eutecticevaporate solvent aqueous two-phase solution to the aqueous solution containing alizarin yellow is 1: 1, the extraction efficiency of the alizarin yellow dye is as high as 99.47%.

Description

Technical Field

[0001] This invention belongs to the field of eutectic solvent technology, specifically relating to the application of a benzyltributyldiethylene glycol eutectic solvent-salt solution aqueous two-phase system in the extraction of alizarin yellow dye. Background Technology

[0002] The textile industry uses approximately 10,000 tons of synthetic dyes annually. These synthetic dyes are toxic, and their discharge into aquatic environments as wastewater leads to the release of pollutants containing high concentrations of pollutants. The molecular structures of these toxic dyes are highly stable, making them difficult to degrade in water treatment plants. Most dyes used in the textile industry are azo (N=N) type, such as Alizarin Yellow (MO), characterized by water solubility, good stability, and resistance to chemical reactions. Therefore, exploring effective extractants is crucial for achieving rapid, efficient capture and stable storage of Alizarin Yellow dye.

[0003] Eutectic solvents are "ionic liquid-like" solvents composed of hydrogen bond acceptors and hydrogen bond donors in varying proportions. Besides possessing the characteristics of ionic liquids such as low vapor pressure, non-volatility, and good thermal stability, they also feature simple synthesis, low raw material costs, and high atom utilization. They are applicable to a wider range of fields and have attracted increasing attention from researchers.

[0004] Dyes exhibit a greater affinity for the hydrophobic phase (the DES-rich upper phase) than for the hydrophilic phase (the salt-rich phase). This behavior of anionic azo dyes is due to their inherent high hydrophobicity. Alizarin Yellow has been successfully extracted and separated from aqueous solutions. Furthermore, based on experience and experiments, a low-cost, simplest-to-operate, and most effective eutectic solvent can be designed to maximize economic benefits. Summary of the Invention

[0005] To address the aforementioned problems, this invention provides a method for extracting alizarin yellow dye using a benzyltributyldiethylene glycol eutectic solvent-salt solution aqueous two-phase system. This method is simple to operate and yields excellent results.

[0006] The technical solution adopted in this invention is:

[0007] An application of a benzyltributyldiethylene glycol eutectic solvent-salt solution aqueous two-phase system in the extraction of alizarin yellow dye is disclosed. The method is as follows: the benzyltributyldiethylene glycol eutectic solvent-salt solution aqueous two-phase system is placed in an aqueous solution of alizarin yellow, and alizarin yellow is separated under constant temperature and stirring conditions; the benzyltributyldiethylene glycol eutectic solvent is synthesized from benzyltributylammonium chloride and diethylene glycol, as shown in structural formulas (I) and (II), respectively; the salt solution is a 45% K3PO4 aqueous solution.

[0008]

[0009] Furthermore, in the above application, the ratio by mass is: benzyltributyldiethylene glycol eutectic solvent-salt solution aqueous two-phase system: alizarin yellow aqueous solution = 1:1.

[0010] Furthermore, in the above application, the concentration of alizarin yellow in the alizarin yellow aqueous solution is 0.2 g·L⁻¹. -1 .

[0011] Furthermore, in the above application, the temperature of the constant-temperature stirring is 25°C.

[0012] Furthermore, in the above-described application, the preparation method of the benzyltributyldiethylene glycol eutectic solvent-salt solution aqueous two-phase system includes the following steps:

[0013] 1) The benzyltributylammonium chloride was dried under vacuum;

[0014] 2) Mix benzyltributylammonium chloride and diethylene glycol and stir until a homogeneous and transparent liquid is formed to obtain benzyltributyldiethylene glycol eutectic solvent;

[0015] 3) The benzyltributyldiethylene glycol eutectic solvent was dried under vacuum;

[0016] 4) Mix the vacuum-dried benzyltributyldiethylene glycol eutectic solvent with a 45% K3PO4 aqueous solution.

[0017] Furthermore, in the above-mentioned method for preparing the benzyltributyldiethylene glycol eutectic solvent-salt solution aqueous two-phase system, in step 1), the vacuum drying temperature is 60°C and the time is 12h.

[0018] Furthermore, in the above-mentioned method for preparing the benzyltributyldiethylene glycol eutectic solvent-salt solution aqueous two-phase system, in step 2), the molar ratio of benzyltributylammonium chloride and diethylene glycol is 1:3.

[0019] Furthermore, in the above-mentioned method for preparing the benzyltributyldiethylene glycol eutectic solvent-salt solution aqueous two-phase system, in step 2), the stirring reaction time is 3 hours.

[0020] Furthermore, in the above-mentioned method for preparing the benzyltributyldiethylene glycol eutectic solvent-salt solution aqueous two-phase system, in step 3), the vacuum drying temperature is 60°C and the time is 12h.

[0021] Furthermore, in the above-mentioned method for preparing the benzyltributyldiethylene glycol eutectic solvent-salt solution aqueous two-phase system, in step 4), the mass ratio of the benzyltributyldiethylene glycol eutectic solvent to the 45% K3PO4 aqueous solution is 1:1.

[0022] The beneficial effects of this invention are:

[0023] 1. This invention utilizes a benzyltributyldiethylene glycol eutectic solvent-salt solution aqueous two-phase system to extract alizarin yellow dye. The synthesis of the benzyltributyldiethylene glycol eutectic solvent and salt solution is simple and inexpensive.

[0024] 2. This invention utilizes a benzyltributyldiethylene glycol eutectic solvent-salt solution aqueous two-phase system to extract alizarin yellow. The dye exhibits a greater affinity for the hydrophobic phase (the DES-rich upper phase) than for the hydrophilic phase (the salt-rich phase). This allows for the successful extraction of alizarin yellow dye from water with a high extraction rate.

[0025] 3. This invention utilizes a benzyltributyldiethylene glycol eutectic solvent-salt solution aqueous two-phase system to extract alizarin yellow dye. This method is in line with the concept of green environmental protection and is more beneficial to the life and survival of humans, animals and plants. Attached Figure Description

[0026] Figure 1 This is the infrared spectrum of the benzyltributyldiethylene glycol eutectic solvent in Example 1. Detailed Implementation

[0027] The invention will be further illustrated below with specific examples. The invention is not limited to the embodiments described, but is equally applicable to other eutectic solvents, with minor variations possible without departing from the scope described.

[0028] Example 1

[0029] Preparation method of benzyltributyldiethylene glycol eutectic solvent-salt solution aqueous two-phase system:

[0030] 1) Dry benzyltributylammonium chloride under vacuum at 60°C for 12 hours.

[0031] 2) Mix benzyltributylammonium chloride and diethylene glycol in a molar ratio of 1:3 and stir for 3 hours until a homogeneous and transparent liquid is formed, thus obtaining benzyltributyldiethylene glycol eutectic solvent.

[0032] 3) Dry the benzyltributyldiethylene glycol eutectic solvent under vacuum at 60°C for 12 h.

[0033] 4) The benzyltributyldiethylene glycol eutectic solvent after vacuum drying was mixed with a 45% K3PO4 aqueous solution at a mass ratio of 1:1 to obtain a benzyltributyldiethylene glycol eutectic solvent-salt solution aqueous two-phase system.

[0034] Characterization methods:

[0035] Infrared spectra: Infrared characterization of benzyltributyldiethylene glycol eutectic solvent is shown in [reference needed]. Figure 1Infrared spectral analysis revealed that the infrared spectrum of the eutectic solvent of benzyltributyl diethylene glycol contained characteristic peaks of both the hydrogen bond acceptor (benzyltributylammonium chloride) and the hydrogen bond donor (diethylene glycol), without the formation of any new characteristic peaks. This indicates that there was no chemical reaction between benzyltributylammonium chloride and diethylene glycol to produce a new substance; they were simply bonded together through hydrogen bond interactions.

[0036] Example 2: Application of the benzyltributyldiethylene glycol eutectic solvent-salt solution aqueous two-phase system in the extraction of alizarin yellow dye.

[0037] (I) Extraction and Separation Experiment

[0038] Dissolve a certain amount of alizarin yellow in water to prepare a solution with a concentration of 0.2 g·L⁻¹. -1 Alizarin Yellow aqueous solution was prepared for later use. 1 g of the benzyltributyldiethylene glycol eutectic solvent-salt solution aqueous two-phase system prepared in Example 1 was weighed into a 10 mL test tube, and 1 g of alizarin Yellow aqueous solution was added. The mass ratio of the benzyltributyldiethylene glycol eutectic solvent-salt solution aqueous two-phase system to the alizarin Yellow aqueous solution was 1:1. Extraction and separation experiments of alizarin Yellow dye were conducted with magnetic stirring at 25 °C.

[0039] After extraction for 20 min, the concentration of alizarin yellow dye in the aqueous phase at a wavelength of 385 nm was measured using UV-Vis spectrophotometry. Three measurements were taken, and the average value was controlled within 3% to ensure data accuracy.

[0040] The extraction efficiency (E%) of alizarin yellow dye is calculated according to formula (1-1):

[0041] E%= [(C0-C f ) / C0] × 100% (1-1)

[0042] Where C0 represents the initial concentration of alizarin yellow in the alizarin yellow aqueous solution, C f This represents the concentration of the remaining alizarin yellow dye in the aqueous phase.

[0043] (II) Extraction rate of alizarin yellow dye by benzyltributyldiethylene glycol eutectic solvent-salt solution aqueous two-phase system

[0044] After extraction using a benzyltributyldiethylene glycol eutectic solvent-salt solution aqueous two-phase system, the extraction efficiency of alizarin yellow dye was calculated to be 99.47%.

Claims

1. The application of a benzyltributyldiethylene glycol eutectic solvent-salt solution aqueous two-phase system in the extraction of alizarin yellow dye, characterized in that, The method is as follows: A benzyltributyldiethylene glycol eutectic solvent-salt solution aqueous two-phase system is placed in an alizarin yellow aqueous solution, and alizarin yellow is separated under constant temperature stirring conditions; the benzyltributyldiethylene glycol eutectic solvent is synthesized from benzyltributylammonium chloride and diethylene glycol, as shown in structural formulas (I) and (II), respectively; the salt solution is a 45% K3PO4 aqueous solution; 2. The application according to claim 1, characterized in that, The mass ratio of benzyltributyldiethylene glycol eutectic solvent-salt solution aqueous two-phase system to alizarin yellow aqueous solution is 1:

1.

3. The application according to claim 2, characterized in that, The concentration of alizarin yellow in the aqueous solution is 0.2 g·L⁻¹. -1 .

4. The application according to claim 1, characterized in that, The temperature of the constant temperature stirring is 25°C.

5. The application according to claim 1, characterized in that, The preparation method of the benzyltributyldiethylene glycol eutectic solvent-salt solution aqueous two-phase system includes the following steps: 1) The benzyltributylammonium chloride was dried under vacuum; 2) Mix benzyltributylammonium chloride and diethylene glycol and stir until a homogeneous and transparent liquid is formed to obtain benzyltributyldiethylene glycol eutectic solvent; 3) The benzyltributyldiethylene glycol eutectic solvent was dried under vacuum; 4) Mix the vacuum-dried benzyltributyldiethylene glycol eutectic solvent with a 45% K3PO4 aqueous solution.

6. The application according to claim 5, characterized in that, In step 1), the vacuum drying temperature is 60°C and the time is 12 hours.

7. The application according to claim 5, characterized in that, In step 2), the molar ratio of benzyltributylammonium chloride to diethylene glycol is 1:

3.

8. The application according to claim 5, characterized in that, In step 2), the stirring reaction takes 3 hours.

9. The application according to claim 5, characterized in that, In step 3), the vacuum drying temperature is 60°C and the time is 12 hours.

10. The application according to claim 5, characterized in that, In step 4), the mass ratio of the benzyltributyldiethylene glycol eutectic solvent to the 45% K3PO4 aqueous solution is 1:1.

Images