Effective Removal of Lead Ions by Alternative Agro- waste Adsorbent from Aqueous Media

Aims: The main goal of this work was to evaluate the removal of lead (II) from aqueous media by using low cost, natural, locally available, environmentally friendly and agricultural waste biosorbent of Molokhia husk (Mh) through batch experiments.

Methods: Different parameters were studied through batch experiments. The surface of Molokhia husk (Mh) before and after adsorption of lead ions was characterized by using FTIR analysis.

Results: It was observed that the maximum adsorption capacity 12.062 mg/g occurred at pH 5, adsorbent mass 0.8 g and contact time 90 min. The percentage removal of adsorption of Pb(II) onto Molokhia husk was 97.82%. Different adsorption isotherms models were used. Equilibrium data fitted well with the Freundlich isotherm (R2 0.9429). Adsorption equilibrium was established after 90 min of contact time. The adsorption energy for Mh calculated from D-R equation 1.291 KJ/ mol indicating the physical adsorption process for removal of Pb (II). Different kinetic models were applied to study the kinetic data of adsorption. Kinetic studies demonstrated that the adsorption of Pb(II) by Mh followed a pseudo second-order model.

Conclusions: These results suggest that Mh could be used as a natural, cheap, low cost and environmentally friendly biosorbent and for removal of lead ions from aqueous media.