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 equations were selected to follow the adsorption processes. Kinetic studies showed that the adsorption followed pseudo-second order model. Various thermodynamic parameters such as Δ𝐻, Δ𝑆 and Δ𝐺 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.
Wahoud, AbdulRahman Yousef and Almaqdi, Sawsan Awadh
"Thermodynamics and Kinetics Studies of Methylene Blue Adsorption Onto Yemeni Palm-Date Stones,"
Hadhramout University Journal of Natural & Applied Sciences: Vol. 16
, Article 4.
Available at: https://digitalcommons.aaru.edu.jo/huj_nas/vol16/iss2/4