Equilibrium Modeling and Kinetic Studies on the Adsorption of Basic Dye by a Low Cost Adsorbent

An agricultural waste and eco-friendly biosorbent i.e. rice husk has been used as a cheap adsorbentfor the removal of methylene blue dye from aqueous solutions. The physical properties of the developedadsorbent were characterized using FTIR. The study was realized using batch experiments. The effectsof contact time, pH, initial dye concentration, biosorbent dose and temperature were investigated. Theadsorption data were evaluated by Freundlich and Langmuir isotherm models. The adsorption isotherm isbest fitted by the Freundlich model, while the adsorption kinetics is well described by the pseudo-secondordermodel. Different thermodynamic parameters i.e., changes in standard free energy, enthalpy andentropy have also been evaluated and it has been found that the dye adsorption onto rice was a spontaneous,endothermic and physical reaction.