Modeling of adsorption isotherms of Methylene Blue onto Natural Illitic Clay: Nonlinear regression analysis

Abstract

The adsorption of Methylene Blue (MB) from aqueous solution onto Natural Illitic clay (NIC) has been studied and the equilibrium isotherms were determined. The experimental data obtained at different initial concentrations were analysed using eight isotherm models. In order to determine the best fit isotherm, five nonlinear error functions were used to evaluate the data. The error analysis demonstrated that the Redlich – Peterson model has better described the MB adsorption data onto NIC. Furthermore, the adsorption nature was determined from isotherm parameters, and it was concluded that the physic-sorption is the appropriate mechanism adsorption to MB onto NIC.