Adsorption Equilibrium Thermodynamics and Kinetics Studies of Chromium (VI) Ions from Aqueous Solution by Using Odina Wodier Bark Carbon

The adsorption behavior of Chromium (VI) ions from aqueous solution on Odina Wodier (OW) bark carbon was investigated as a function of parameters such as adsorbent dose, initial Chromium (VI) ions concentration, and effect of solution pH, contact time and temperature. The Freundlich and Langmuir adsorption models were applied to describe the equilibrium isotherms. From these experimental data and R_L value indicate the adsorption process is favourable. The thermodynamic parameters such as ΔH⁰, ΔS⁰ and ΔG⁰ were evaluated and the adsorption process was physical adsorption. The pseudo-first-order, pseudo-second-order, Elovich kinetic models and the intra-particle diffusion model were used to fit the experimental data by using linear regression analysis method. The high correlation coefficient (γ) values indicate the fitness of the model. The mechanism of adsorption is confirmed by the analytical tools such as FT-IR, XRD and SEM images. The kinetic of this process having high correlation coefficient (γ) were pseudo-second-order and intra-particle diffusion models. The Odina Wodier (OWC) bark carbon has high adsorption capacity and adsorption rate for the removal of Chromium (VI) ions from aqueous solution.