Adsorption of Congo Red on Multiwall Carbon Nanotubes: Equilibrium Isotherm and Kinetic StudiesAuthor(s): Ahmed M. Kamil, Halah T. Mohammed, Ayad F. Alkaim and Falah H. Hussein
In this work, the adsorption capacity of an aqueous solution of Congo Red (CR) dye was used as a model of wastewater treatment to study the treatment activity of multiwall carbon nanotubes (MWCNTs). The adsorption capacity of an aqueous solution of CR onto MWCNTs surface was investigated, particularly focusing on the influence of the experimental parameters on the kinetics adsorption at constant conditions, such as MWCNTs dosage, initial concentration, pH, ionic strength and temperature. Langmuir and Freundlich isotherms were used as the model adsorption equilibrium data. The constants of Langmuir and Freundlich models are obtained from fitting the adsorption equilibrium data. The correlation coefficients of Langmuir and Freundlich models are 0.9906 and 0.9662, respectively. The pseudo-first order, pseudo-second order and intraparticle diffusion models were used to describe the adsorption kinetics. The experimental adsorption data fitted with the pseudo-second order kinetic.