A carvacrol-based hydrophobic eutectic solvent extractant, its preparation method, and its application in the extraction of quinoline from coking wastewater.
By using carvacrol-based hydrophobic eutectic solvent extractant to efficiently extract quinoline from coking wastewater under mild conditions, the problem of difficult removal of quinoline pollutants from coking wastewater has been solved, achieving low-cost, high-efficiency pollutant separation and resource utilization.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- DALIAN UNIV OF TECH PANJIN INST OF IND TECH
- Filing Date
- 2026-01-29
- Publication Date
- 2026-05-26
AI Technical Summary
Quinoline pollutants in coking wastewater are difficult to remove effectively, and existing technologies are costly, inefficient, and harmful to the environment.
Using carvacrol-based hydrophobic eutectic solvent as the extractant, quinoline was extracted with an aqueous solution containing quinoline under constant temperature and stirring conditions. The hydrogen bonding ability of the phenolic hydroxyl group of carvacrol, the π-π stacking effect of the benzene ring, and the hydrophobic synergistic effect of the long carbon chain of octanol were utilized to achieve efficient extraction of quinoline.
It achieves high-efficiency extraction of quinoline from coking wastewater under low cost and mild conditions, with good environmental compatibility and high extraction efficiency. Suitable extraction conditions and ratios ensure high selectivity and rapid mass transfer process.
Smart Images
Figure CN121591286B_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the field of energy conservation and environmental protection, specifically to a carvacrol-based hydrophobic eutectic solvent extractant and its preparation method, and its application in the extraction of quinoline from coking wastewater. Background Technology
[0002] The coking industry has made significant contributions to the development of local economies in my country, but the pollution caused by coking wastewater cannot be ignored. Coking wastewater is a type of industrial organic wastewater characterized by high pollutant concentrations, strong toxicity, and difficulty in degradation. Among these pollutants, quinoline, a typical recalcitrant organic compound in coking wastewater, is highly toxic and, if not effectively treated, will pose a threat to human health and the growth of plants and animals. Therefore, removing quinoline from coking wastewater is crucial for improving water quality and protecting the environment.
[0003] Eutectic solvents (DESs), as a novel type of green material, are prepared by directly mixing hydrogen bond acceptors (HBAs) such as metal halides and quaternary ammonium salts with hydrogen bond donors (HBDs) such as alcohols, amides, and carboxylic acids. They not only possess advantages such as low volatility, designable physicochemical properties, and wide application range, but also utilize green and inexpensive raw materials, have a simple and easy preparation process, and exhibit excellent environmental compatibility. This provides a completely new technological platform for the innovative development of separation processes.
[0004] Carvacrol, a natural phenolic compound, and octanol, a commonly used fatty alcohol in industry, are both basic raw materials widely used in the chemical and daily chemical industries. Their abundant sources and low prices significantly reduce the operating costs of extraction processes. Compared to traditional organic solvents, the carvacrol-octanol eutectic solvent extraction system combines the hydrogen bonding ability of the phenolic hydroxyl groups of carvacrol, the π-π stacking effect of the benzene ring, and the hydrophobic synergistic effect of the long carbon chain of octanol. This results in a richer number of recognition and complexation sites for quinoline, a nitrogen-containing heterocyclic pollutant, providing a new technical pathway for the efficient removal of quinoline pollutants from coking wastewater and the deep purification and resource utilization of coking wastewater. Summary of the Invention
[0005] The carvacrol-based hydrophobic eutectic solvent provided by this invention can effectively extract quinoline from water. This method is low in cost, mild in conditions, simple to operate, highly efficient in extraction, and environmentally compatible.
[0006] To achieve the above objectives, the technical solution adopted by the present invention is as follows: a carvacrol-based hydrophobic eutectic solvent and its application in the extraction of quinoline from coking wastewater. The method is as follows: the carvacrol-based hydrophobic eutectic solvent is placed in an aqueous solution containing quinoline, and the quinoline is extracted under constant temperature and stirring conditions.
[0007] The first aspect of this invention provides a carvacrol-based hydrophobic eutectic solvent extractant with the following structural formula (I):
[0008]
[0009] (I).
[0010] A second aspect of this invention provides a method for preparing a carvacrol-based hydrophobic eutectic solvent extractant, comprising the following steps:
[0011] 1) Drying of carvacrol and octanol: Carvacrol and octanol were placed in a vacuum drying process;
[0012] 2) Preparation of carvacrol-based hydrophobic eutectic solvent: Carvacrol and octanol are mixed and heated and stirred until a homogeneous, transparent, and clear liquid is formed. Then, the liquid is dried under vacuum to remove moisture and obtain the target eutectic solvent.
[0013] In the above-mentioned method for preparing a carvacrol-based hydrophobic eutectic solvent extractant, step 1) involves a vacuum condition of 0.09 MPa and a vacuum temperature of 60 °C for 48 h.
[0014] In the above-mentioned method for preparing a carvacrol-based hydrophobic eutectic solvent extractant, in step 2), the molar ratio of carvacrol to octanol is 1:1.
[0015] In the above-mentioned method for preparing a carvacrol-based hydrophobic eutectic solvent extractant, step 2) involves a heating and stirring reaction temperature of 60 °C.
[0016] In the above-mentioned method for preparing a carvacrol-based hydrophobic eutectic solvent extractant, step 2) involves a heating and stirring reaction time of 30 min.
[0017] The third aspect provides an application of carvacrol-based hydrophobic eutectic solvent extractant for extracting quinoline from coking wastewater, including the following steps: The method for extracting quinoline from water is as follows: carvacrol-based hydrophobic eutectic solvent is placed in an aqueous solution containing quinoline, and quinoline is extracted from water under certain volume ratio, reaction temperature, pH value, extraction time and quinoline concentration. After the reaction is completed, the mixture is allowed to stand and separate into layers, and the lower layer is the aqueous phase after quinoline removal.
[0018] The above-mentioned application of a carvacrol-based hydrophobic eutectic solvent extractant for extracting quinoline from coking wastewater has a volume ratio of extractant to aqueous solution containing quinoline of 1:10 to 1:30.
[0019] The above-mentioned application of a carvacrol-based hydrophobic eutectic solvent extractant for extracting quinoline from coking wastewater has an aqueous solution containing quinoline with a pH of 4-10.
[0020] The above-mentioned application of a carvacrol-based hydrophobic eutectic solvent extractant for extracting quinoline from coking wastewater involves a reaction process in which an aqueous solution containing quinoline and the extractant are mixed, with a reaction temperature of 25~60 ℃.
[0021] The above-mentioned application of a carvacrol-based hydrophobic eutectic solvent extractant for extracting quinoline from coking wastewater involves a reaction process in which the aqueous solution of quinoline and the extractant are mixed, with a reaction time of 2-40 min.
[0022] The above-mentioned application of a carvacrol-based hydrophobic eutectic solvent extractant for extracting quinoline from coking wastewater, wherein the concentration of quinoline in the aqueous solution is 50~500 mg / L.
[0023] Compared with the prior art, the present invention has the following significant advantages:
[0024] 1. The carvacrol-based hydrophobic eutectic solvent prepared by this invention has low raw material cost, simple preparation process, environmental friendliness and non-volatile properties, and is liquid at room temperature, making it a green solvent with great application prospects.
[0025] 2. The carvacrol-based hydrophobic eutectic solvent prepared by this invention has a strong ability to remove quinoline from coking wastewater. Simultaneously, this eutectic solvent has good phase-forming ability with water, achieving phase separation with a relatively small dosage.
[0026] 3. The carvacrol-based hydrophobic eutectic solvent prepared by this invention combines the hydrogen bonding ability of the carvacrol hydroxyl group, the π-π stacking effect of the benzene ring, and the hydrophobic synergistic effect of the long carbon chain of octanol, thus achieving the purpose of efficient extraction and separation of quinoline in water.
[0027] 4. The carvacrol-based hydrophobic eutectic solvent prepared by this invention has advantages such as mild reaction conditions, short reaction time, small dosage and high removal efficiency in the application of quinoline removal in water extraction. Attached Figure Description
[0028] Figure 1 This is the hydrogen spectrum of the carvacrol-octanol hydrophobic eutectic solvent prepared in Example 1.
[0029] Figure 2 The image shows the infrared spectrum of the carvacrol-octanol hydrophobic eutectic solvent prepared in Example 1.
[0030] Specific implementation methods
[0031] The present invention will be further illustrated by specific examples below. The present invention is not limited to the embodiments described, and minor variations may be made without departing from the scope thereof.
[0032] Example 1
[0033] The preparation method of the carvacrol-based hydrophobic eutectic solvent extractant is as follows:
[0034] 1) Carvacrol and octanol were vacuum dried separately at a vacuum degree of 0.09 MPa and a temperature of 60 °C for 48 h.
[0035] 2) Weigh carvacrol and octanol separately at a molar ratio of 1:1, and then place them in a flask equipped with a stirrer. React at 60 °C for 30 min until a homogeneous, transparent, and clear liquid is formed. After the reaction, dry under vacuum at 0.09 MPa and 60 °C for 48 h to obtain the carvacrol-based hydrophobic eutectic solvent extractant.
[0036] Characterization of carvacrol-based hydrophobic eutectic solvents:
[0037] (1) Proton NMR spectrum: Proton NMR spectrum of carvacrol hydrophobic eutectic solvent ( 1 Characterization by ¹H NMR (solvent: DMSO-d6) is shown in the attached figure. Figure 1 As shown. Spectral analysis indicates that, 1 The chemical shifts and number of resonance peaks of the H NMR were consistent with those of the target eutectic solvent, and no impurity peaks were detected.
[0038] (2) Infrared spectrum: The infrared characterization of carvacrol hydrophobic eutectic solvent is shown in the attached figure. Figure 2 As shown in the figure. Infrared spectrum analysis shows that the infrared spectrum of the eutectic solvent contains both characteristic peaks of carvacrol (hydrogen bond acceptor) and characteristic absorption peaks of octanol (hydrogen bond donor), and no new characteristic peaks are generated. This indicates that there is no chemical reaction between carvacrol and octanol to produce new substances, but they are only bonded by hydrogen bond interaction.
[0039] In the following examples, the simulated coking wastewater was prepared by dissolving separately weighed quinoline in deionized water to form an aqueous solution with a concentration of 50-500 mg / L. After quinoline extraction, the concentration of quinoline (312 nm) in the aqueous phase was determined by UV-Vis spectrophotometry. At least three parallel samples were taken from the n-octane phase for quantitative determination of each target analyte, and the relative error at equilibrium was controlled within 2% to ensure data accuracy. The extraction efficiency (E%) of quinoline was calculated according to formula (1-1):
[0040] (1-1)
[0041] Where C0 represents the initial concentration of quinoline in the simulated coking wastewater, and C1 represents the remaining concentration of quinoline after extraction from the simulated coking wastewater.
[0042] Example 2
[0043] 1 mL of the carvacrol-based hydrophobic eutectic solvent prepared in Example 1 was transferred to a 20 mL sample bottle, followed by the addition of 10 mL of quinoline aqueous solution (quinoline concentration 50 mg / L, pH 7). Extraction was performed at 25 °C for 10 min. The quinoline extraction efficiency was measured to be 98.41%.
[0044] Example 3
[0045] 0.5 mL of the carvacrol-based hydrophobic eutectic solvent prepared in Example 1 was transferred to a 20 mL sample vial, followed by the addition of 10 mL of quinoline aqueous solution (quinoline concentration 50 mg / L, pH 7). Extraction was performed at 25 °C for 10 min. The quinoline extraction efficiency was measured to be 84.09%.
[0046] Example 4
[0047] 1 mL of the carvacrol-based hydrophobic eutectic solvent prepared in Example 1 was transferred to a 20 mL sample bottle, followed by the addition of 10 mL of quinoline aqueous solution (quinoline concentration 50 mg / L, pH 6). Extraction was performed at 25 °C for 10 min. The quinoline extraction efficiency was measured to be 79.86%.
[0048] Example 5
[0049] 1 mL of the carvacrol-based hydrophobic eutectic solvent prepared in Example 1 was transferred to a 20 mL sample bottle, followed by the addition of 10 mL of quinoline aqueous solution (quinoline concentration 50 mg / L, pH 7). Extraction was performed at 30 °C for 10 min. The quinoline extraction efficiency was measured to be 86.55%.
[0050] Example 6
[0051] 1 mL of the carvacrol-based hydrophobic eutectic solvent prepared in Example 1 was transferred to a 20 mL sample vial, followed by the addition of 10 mL of quinoline aqueous solution (quinoline concentration 50 mg / L, pH 7). Extraction was performed at 25 °C for 5 min. The quinoline extraction efficiency was measured to be 83.41%.
[0052] Example 7
[0053] 1 mL of the carvacrol-based hydrophobic eutectic solvent prepared in Example 1 was transferred to a 20 mL sample bottle, followed by the addition of 10 mL of quinoline aqueous solution (quinoline concentration 100 mg / L, pH 7). Extraction was performed at 25 °C for 10 min. The quinoline extraction efficiency was measured to be 90.41%.
[0054] In summary, when extracting quinoline from water using the carvacrol-based hydrophobic eutectic solvent prepared in Example 1, the optimal extraction efficiency (98.41%) was achieved when the volume ratio of the carvacrol-based hydrophobic eutectic solvent to the quinoline aqueous solution was 1:10, the quinoline concentration was 50 mg / L, the pH was 7, the extraction temperature was 25 °C, and the extraction time was 10 min. The high efficiency of quinoline extraction (98.41%) under these conditions is mainly attributed to the following synergistic effects: First, the prepared carvacrol-octanol-based hydrophobic eutectic solvent possesses an aromatic structure and hydrophobic properties similar to the quinoline molecule, achieving high selectivity and efficient dissolution of quinoline through π-π interactions and hydrophobic effects. Second, at a volume ratio of 1:10, the eutectic solvent and the quinoline aqueous solution form an optimal phase interface. The organic phase provides sufficient hydrophobic interaction sites while avoiding increased mass transfer resistance due to excessively high proportions, ensuring sufficient contact between the two phases. In a neutral system at pH 7, quinoline exists in its molecular state. Its heterocyclic structure can form weak hydrogen bonds with the phenolic hydroxyl groups of carvacrol and the hydroxyl groups of octanol. Furthermore, molecular quinoline is more readily adsorbed by hydrophobic eutectic solvents, avoiding the inhibition of extraction caused by quinoline protonation or solvent phase changes under acidic or alkaline conditions. The suitable temperature of 25 °C ensures the molecular diffusion rate while avoiding potential solvent loss or structural changes at high temperatures. An extraction time of 10 minutes indicates that the mass transfer process quickly reaches equilibrium, demonstrating the excellent extraction kinetics of this eutectic solvent system. This avoids insufficient extraction in short times while preventing back-extraction or system emulsification caused by prolonged stirring, ultimately achieving efficient separation of quinoline.
[0055] The above description pertains only to the preferred embodiments of the present invention. The present invention is not limited to the above embodiments.
Claims
1. The application of a carvacrol-based hydrophobic eutectic solvent extractant in the extraction of quinoline from coking wastewater, characterized in that, The method is as follows: The carvacrol-based hydrophobic eutectic solvent is placed in coking wastewater containing quinoline. Under certain volume ratios, reaction temperatures, pH values, extraction times, and quinoline concentrations, quinoline in the water is extracted. After the reaction is completed, the mixture is allowed to stand and separate into layers. The lower layer is the aqueous phase after quinoline removal. The structure of the carvacrol-based hydrophobic eutectic solvent is shown in formula (Ⅰ): （Ⅰ）； The preparation method of the carvacrol-based hydrophobic eutectic solvent extractant includes the following steps: Step 1: Drying of carvacrol and octanol. Carvacrol and octanol were vacuum dried at 0.09 MPa and 60 °C for 48 h. Step 2: Preparation of carvacrol-based hydrophobic eutectic solvent: Carvacrol and octanol are mixed in a molar ratio of 1:1 and heated and stirred at 60°C for 30 min until a homogeneous, transparent, and clear liquid is formed. The mixture is then dried under vacuum to obtain the target eutectic solvent.
2. The application of the carvacrol-based hydrophobic eutectic solvent extractant according to claim 1 for extracting quinoline from coking wastewater, characterized in that, The volume ratio of the carvacrol-based hydrophobic eutectic solvent to the coking wastewater containing quinoline is 1:10 to 1:30, and the concentration of quinoline in the coking wastewater is 50 to 500 mg / L.
3. The application of the carvacrol-based hydrophobic eutectic solvent extractant according to claim 1 for extracting quinoline from coking wastewater, characterized in that, The pH of aqueous solutions containing quinoline is 4-10.
4. The application of the carvacrol-based hydrophobic eutectic solvent extractant according to claim 1 for extracting quinoline from coking wastewater, characterized in that, During the extraction process, the extraction temperature is 25~60 ℃.
5. The application of the carvacrol-based hydrophobic eutectic solvent extractant according to claim 1 for extracting quinoline from coking wastewater, characterized in that, During the extraction process, the extraction time is 2 to 40 minutes.