Adsorption of methylene blue, a basic dye onto activated Prosopis spicigera, prepared from dried fruit of the member of leguminasae family by batch adsorption method has been investigated. The operating variables studied are the initial dye concentration, initial solution pH, adsorbent dosage and contact time. Equilibrium data were successfully applied to study the kinetics and mechanism of adsorption of dye onto activated carbon. The kinetics of adsorption was found to be pseudo second order with regard to intraparticle diffusion. The pseudo second order is further supported by Elovich model, which in turn auguments the fact of chemisorption of dye onto the carbon. Quantitative removal of dye at higher pH of dye solution confirms the basic nature of MB and acidic nature of activated carbon. Equilibrium adsorption data were also analyzed by Langmuir and Freundlich models.
Methylene blue, Activated carbon, Adsorption isotherm, Kinetics, Elovich, SAPS