Abstract

Adsorption of ferrous ion by activated carbon-kinetic and equilibriumstudies

Author(s): S.Arivoli, M.Hema

A carbonaceous adsorbent prepared from an indigenous waste, by acid treatment was tested for its efficiency in removing ferrous ion. The process parameters studied include agitation time, initialmetal ion concentration, carbon dose, pH and temperature. The adsorption followed first order reaction equation and the rate is mainly controlled by intraparticle diffusion. Freundlich and Langmuir isotherm models were applied to the equilibriumdata. The adsorption capacity (Qm) obtained fromthe Langmuir isothermplotwere found to 42.52, 41.32, 39.84 and 38.71mg/g at an initial pH of 7.0. The temperature variation study showed that the ferrous ions 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 ferrous ion solutions. The Langmuir and Freundlich adsorption isotherms obtained, positive H0 value, pH dependent results and desorption of metal ions in mineral acid suggest that the adsorption of ferrous ion on MCC involves chemisorption as well as physisorption mechanism.