Equilibrium, kinetic, thermodynamic applications for methylene blue removal using Buxus sempervirens leaf powder as a powerful low-cost adsorbent

Document Type: Research Paper


1 Department of Chemical Engineering, Iran University of Science & Technology, Narmak 16846-13114, Tehran, Iran

2 Iran University of Science and Technology



In this work, methylene blue adsorption using unconventional, natural, and low-cost adsorbent, Buxus Sempervirens (Boxwood) leaf powder (BLP), was studied. Several experiments for the investigation of different process variables were done, and through a series of methods, XRF, XRD, SEM, FTIR, N2 adsorption-desorption of the adsorbents were characterized. Adsorption kinetic models showed that pseudo-second-order by R2=0.999 was well adapted. Two isotherms models, Langmuir and Freundlich, were selected for checking of the amount of color removal. Methylene blue (MB) maximum adsorption capacities can attain 384.61 mg/g from the Langmuir isotherm. The values of ∆G^0 for adsorption of MB onto BLP ranges from -19.44 to -24.07 kJ/mol, demonstrating that the adsorption process was spontaneous and irreversible. The removal of dye was considerably increased by increasing in temperature which suggested that the adsorption process was endothermic. All results indicate that the BLP can feasibly employ for the elimination of MB from aqueous solution.