Study of removal of phenol species by adsorption on non-ionic silicon surfactant after cloud point extraction methodology

In the present study, CPE was carried out to extract phenol species from aqueous solution using the non-ionic silicone surfactant of DC193C. The non-ionic silicone surfactant of DC193C was chosen because of it is well known as an environmentally friendly solvent. The adsorption mechanism between the non-ionic silicone surfactant of DC193C and phenol species was studied. Our results indicate that, the adsorption of the phenol species from aqueous solution on the DC193C surfactant was in proportion to their hydrophobicities, according to the following order; 4-NP < 2,4-DCP < 2,4,6-TCP. The data of the equilibrium concentration and amount of adsorption in the CPE system for the three phenols species follow the Langmuir-type isotherm. On some assumptions, a developed Langmuir isotherm was used to calculate the feed surfactant concentration required for the removal of the three phenol species up to the extraction efficiency of 90%. The developed correlations may be useful to design a cloud point extractor of a desired efficiency. Thermodynamic parameters including the Gibbs free energy (ΔG°), enthalpy (ΔH°), and entropy (ΔS°) were also calculated. These parameters indicated that the adsorption of the three phenol species solubilized into the non-ionic DC193C surfactant is feasible, spontaneous, and endothermic in the temperature ranging from 298 to 353 K

Cloud point extraction of 2,4−dichlorophenol from aqueous samples employing β−cyclodextrin

In this study, β−cyclodextrin (β−CD) was used to enhance the extraction of 2,4−dichlorophenol (2,4−DCP) from the aqueous sample in cloud point extraction (CPE) using spectrophotometric method. Several parameters have been investigated with and without the presence of β−CD modifier, such as pH, equilibration temperature, analyte concentration, and water content in the CPE and CPE−βCD systems, respectively. Equilibrium data are described by the Langmuir isotherm in both CPE systems with and without β−CD modifier. The thermodynamic parameters (positive values of ΔH° and ΔS°, negative values of ΔG°) indicate that the solubilization of 2,4−DCP in a polyethylene glycol silicone surfactant (DC193C) is endothermic, entropy gained, and spontaneous in both systems. In the CPE−βCD system, the results show that the β−CD modifier is capable of enhancing the extraction of 2,4−DCP pollutant from aqueous samples

Cyclodextrin modified ionic liquid material as a modifier for cloud point extraction of phenolic compounds using spectrophotometry

A greener method based on cloud point extraction (CPE) in the presence of b-cyclodextrin (CPE-bCD) and β-cyclodextrin functionalized with ionic liquids (CPE- β CD-IL) systems were investigated and compared for the removal of 2,4,6-TCP and 4-NP in aqueous sample using UV-Vis spectrophotometric method. In the present study, β CD-IL modifier, was used in CPE- β CD-IL system as an enhancement in the removal of 2,4,6-TCP and 4-NP. The removal of 2,4,6-TCP and 4-NP were optimum at pH 7 with concentration of DC193C, 0.5 (v/v %), for this work. Apart from that, the removal process was found to be optimum at 10 mg L-1 of both modifies concentration. For the isotherm study, monolayer solubilization capacity is greater for 2,4,6-TCP than 4-NP. The performance of the β CD-IL modifier towards the hydrophilic 4-NP showed enhanced extraction efficiency in the present study as compared to the β -CD modifier. Finally, the interactions between the cavity of β CD-IL with 4-NP and DC193C were investigated and the results show that the inclusion of the complex formation, hydrogen bonding between DC193C and 4-NP, π- π interaction, electrostatic attraction between the imidazolium ring of the β CD-IL was the main interactions involved in the extraction process