Adsorption kinetics ofmalachite green by activated low cost carbonAuthor(s): S.Arivoli, P.Martin Deva Prasath, M.Hema
A carbonaceous adsorbent prepared from an indigenous waste by acid treatment was tested for its efficiency in removing Malachite green. The parameters studied include agitation time, initial dye concentration, carbon dose, pH and temperature. The adsorption followed first order reaction equation and the rate is mainly controlled by intra-particle diffusion. Freundlich and Langmuir isothermmodelswere applied to the equilibrium data. The adsorption capacity (Qm) obtained from the Langmuir isotherm plotswere 63.41, 63.86, 64.43 and 67.06mg/g respectively at an initial pHof 7.0 at 30, 40, 50 and 600C. The temperature variation study showed that the Malachite green adsorption is endothermic and spontaneous with increased randomness at the solid solution interface. Significant effect on adsorption was observed on varying the pH of the Malachite green solutions. Almost 90%removal ofMalachite green was observed at 600C. The Langmuir and Freundlich isotherms obtained, positive ïH0 value, pH dependent results and desorption of dye in mineral acid suggest that the adsorption of Malachite green on MCC involves physisorption mechanism.