Adsorption of Pb (II) from aqueous solution by Cassia fistula seed carbon: Kinetics, equilibrium, and desorption studies

Thermal activation of Cassia fistula seed carbon and its subsequent adsorption of Pb (II) has been studied by batch adsorption technique. The main objectives of this study were to: 1) investigate the lead adsorption from aqueous solution using C. fistula seed carbon, 2) study the influence of contact time, adsorbent dose, pH and initial metal ion concentration on adsorption process performance and 3) determine the appropriate adsorption isotherm and kinetic parameters of lead adsorption on C. fistula seed carbon. The experimental adsorption data fitted reasonably well with Freundlich adsorption isotherms. The maximum Langmuir adsorbent capacity (Q(0)) was 47.62 mg/g. Kinetic evaluation of the experimental data showed that the adsorption process followed pseudo-second order kinetics. The present study showed that thermally activated carbon prepared from C. fistula seed was capable of removing lead from aqueous solutions. The cost of removal is expected to be quite low, as the adsorbent is cheap and easily available in large quantities. (c) 2016 American Institute of Chemical Engineers Environ Prog, 36: 138-146, 2017