Recovery of phenylethyl alcohol from aqueous solution by batch adsorption

Abstract Adsorption of phenylethyl alcohol (PEA) from aqueous solution onto Macronet MN202 was carried out by batch experiments. The effects of initial PEA concentration (250–6,000 mg L −1 ), adsorbent amount (0.025–1 g), and temperature (25–40°C) on the adsorption capacity were investigated. The influence of contact time on adsorption showed that 2 h was adequate for 80.3 ± 4.13% PEA removal (86.6 ± 4.20% for 24 h). Batch experiment equilibrium data were examined using the isotherm and kinetics model approaches. The maximum adsorption capacity q m was found to be 1,250 mg g −1 by the Langmuir isotherm model. Both Langmuir and Freundlich's isotherms and adsorption–desorption cycles confirmed that the mechanism was physical adsorption, besides the Temkin isotherm confirmed that the adsorption is favorable. In addition, the mean free energy of 8.2249 ± 0.2033 kJ mol −1 obtained from the Dubinin–Radushkevich model showed that the adsorption mechanism was associated with reversible ion exchange. It was observed that the adsorption kinetics were compatible with the pseudo-second-order and intraparticle diffusion kinetics models. The thermodynamical investigation of the adsorption process reflected that the Gibbs free energy was negative, the process was spontaneous, the heat of adsorption was exothermic, and the standard entropy change was negative, which meant that less disorder occurred at the solid–liquid interface.