Thermodynamics and kinetics studies of methylene blue adsorption onto Yemeni palm-date stones

Abstract EN

A raw and baked date stones were used for the removal of methylene blue (MB) from aqueous solutions.

The maximum adsorption capacity was 111 mg/g for raw and 41 mg/g for baked date stones with 10 mmol/l initial concentration of MB, 5 pH and 0.5 g/l adsorbent dose.

The adsorption isotherm was found to follow the Langmuir model.

Two simplified kinetic models including pseudo-first-order and pseudo-second-order equation were selected to follow the adsorption processes.

Kinetic studies showed that the adsorption followed pseudo-second order model.

Various thermodynamic parameters such as ∆H, ∆S and ∆G were evaluated.

The results in this study indicated that the raw Yemeni palm-date stones could be employed as an effective adsorbent for the removal of MB from aqueous solutions.