Sorption isotherms from water solutions for toluene, cyclohexane, o-xylene, benzyl alcohol, phenol and cyclohexanol onto a humic acid-zeolite adduct were determined at 4, 14, 24 and 34 °C and utilized to calculate the isosteric enthalpy (δ adsHi) and isosteric entropy (δ adsSi) of the process. For hydrocarbon compounds, toluene, cyclohexane and o-xylene, both δ adsHi and δ adsSi were negative, the process was exothermic. In contrast, for hydroxyl compounds, benzyl alcohol, phenol and cyclohexanol, δ adsHi and δ adsSi were positive, the increase in entropy possibly reflecting the release of water molecules during sorption. The results suggest that sorption/desorption of either class of compounds could be controlled by operating on the temperature. © 2013.
Sorption of non-ionic organic pollutants onto a humic acids-zeolitic tuff adduct: Thermodynamic aspects
IOVINO, Pasquale;SALVESTRINI, Stefano;Capasso S.
2014
Abstract
Sorption isotherms from water solutions for toluene, cyclohexane, o-xylene, benzyl alcohol, phenol and cyclohexanol onto a humic acid-zeolite adduct were determined at 4, 14, 24 and 34 °C and utilized to calculate the isosteric enthalpy (δ adsHi) and isosteric entropy (δ adsSi) of the process. For hydrocarbon compounds, toluene, cyclohexane and o-xylene, both δ adsHi and δ adsSi were negative, the process was exothermic. In contrast, for hydroxyl compounds, benzyl alcohol, phenol and cyclohexanol, δ adsHi and δ adsSi were positive, the increase in entropy possibly reflecting the release of water molecules during sorption. The results suggest that sorption/desorption of either class of compounds could be controlled by operating on the temperature. © 2013.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
