BackgroundHydrophobic deep eutectic solvents (HDESs) are environmentally friendly solvents that can be used to extract water pollutants, including phenolic compounds. MethodsIn this research, a ternary HDES (thymol: caprylic acid: capric acid = 1:1:1, molar ratio) has been used for the extraction of 2-methyl phenol, 3-methyl phenol and phenol from water. The effect of the HDES on liquid-liquid phase behavior of the ternary mixtures (2-methyl phenol/ 3-methyl phenol / phenol + HDES + water) at 298.15 K was discussed. The NRTL model has been used to correlate the experimental data. The selectivity and distribution coefficient were calculated as the important indexes for evaluating the extraction potential of the ternary HDES. Significant FindingsThe results showed that the ternary HDES can be used as a good extractant for the extraction of 2-methyl phenol, 3-methyl phenol and phenol. Besides, the ternary HDES could extract 2-methyl phenol and 3-methyl phenol better than phenol from their aqueous solutions. Electrostatic potentials, interaction energies and reduced density gradients were used to further investigate the interactions of 2-methyl phenol, 3-methyl phenol and phenol with the ternary HDES.
Read full abstract