Evaluation studies for the eradication of lead ions from aqueous system using Salvadora persica as a potential biosorbent material

Abstract

Biosorption characteristics of an environmentally benign material (Salvadora persica) was investigated for the removal of Pb(II) ions from the aqueous solution. Various parameters like, the effect of sorbent dosages, contact time, pH and temperature on biosorption process were examined in a batch process. The maximum biosorption of Pb(II) ions occurred at 0.50 g of biosorbent at pH 6.0 for the contact time of 80 min. Langmuir, Freundlich and Dubinin-Redushekvich isotherms were applied. Langmuir adsorption isotherm was the best fitted among all the isotherms studied. The biosorption of Pb(II) ions followed the pseudo second order kinetic model. Thermodynamic parameters such as Gibbs free energy (ΔGo), enthalpy (ΔHo) and entropy (ΔSo) were also evaluated. From thermodynamic study it is obvious that biosorption process is feasible, spontaneous and exothermic