| Summary: | A batch adsorption method was applied to study the adsorption of Pb2+ ions from aqueous solution by lalang or Imperata cylindrica (IC) leaf powder. Effect of initial lead concentration, contact time, pH of solution, temperature and adsorbent dose were also investigated. A strong dependence of adsorption capacity on pH was observed as the capacity increased with increasing pH. Adsorption equilibrium was established in about 120 min. Adsorption of lead was found to increase with increasing temperature indicating endothermic nature of adsorption. The kinetic data were analyzed using various kinetic models particularly pseudo-first-order, pseudo-second-order, Ritchie's-second-order, Elovich and intraparticle diffusion equations. Results show that the pseudo-second order kinetic model was found to agree well with the experimental data. Equilibrium isotherm data were tested using three models-Langmuir, Freundlich and Temkin. Equilibrium data agreed well with Langmuir model. The maximum adsorption capacity of lead by IC leaf powder determined from Langmuir model was 5.89 mg g-1 at pH 4. © 2007 Asian Network for Scientific Information.
|
|---|