Methylene blue adsorption onto granular activated carbon prepared from Harmal seeds residue

In this research, application of granular activated carbon prepared from Harmal seeds residue as a new adsorbent for methylene blue (MB) removal from aqueous solutions was investigated. Adsorption equilibrium and kinetic data were studied. The results demonstrated that the equilibrium data were well represented by Langmuir isotherm model, with maximum monolayer adsorption capacity of 1111.11 mg/g. The dimensionless factor (RL) revealed the favorable nature of this adsorption system. The kinetic data were found to follow the pseudo-second-order kinetic model. Effect of initial concentration on the adsorption mechanism of MB onto the prepared activated carbon was also investigated.