Removal of Pb(II) ions from aqueous solutions using bombax ceiba saw dust activated carbon

The isotherms, kinetics and thermodynamics of Pb(II) ions from aqueous solution by activated carbon prepared from Bombax ceiba sawdust (SDC) were carried out in a batch adsorption system. The effects of pH, adsorbent dosage, contact time, initial concentration of Pb(II) and temperature on the adsorption were studied. Maximum adsorption of Pb(II) occurred at pH 5. Pseudo first order, pseudo second order and intraparticle diffusion models were applied to kinetic data. The sorptive mechanism followed the pseudo second-order kinetics and intra particle diffusion model. The equilibration data fitted well with both Langmuir and Freundlich isotherm model with maximum sorption capacity of 209 mg g^-1. The mean free energy of adsorption calculated from Dubinin-Radushkevich (D-R) isotherm model indicated that the adsorption of metal ions was found to be by chemical ion exchange. Thermodynamic parameters and Tempkin constant showed that the sorption process of Pb(II) onto SDC was feasible, spontaneous and endothermic under studied conditions.