Kinetic and Thermodynamic Studies of the Adsorption of Several Anionic Dyes From Water Samples on Magnetite-Modified Multi-Walled Carbon Nanotubes

In this study magnetite-modified multi-walled carbon nanotubes (MMMCNTs) were used as an adsorbent for the removal of four anionic dyes from aqueous solutions. Batch studies were performed to address various experimental parameters for the removal of these dyes. Kinetic studies showed that the adsorption of dyes on MMMCNTs was almost a rapid process. Quasi equilibrium was reached in 45 min. Pseudo-first-order and pseudo-second-order models were applied to fit the experimental data and the results show that the adsorption of dyes followed the pseudo-second-order kinetic model. The thermodynamic analysis indicates an increase in the temperature resulted in increasing the dyes adsorption capacity of the adsorbent indicating the process to be endothermic.