Nigella sativa L. seeds biomass as a potential sorbent in sorption of lead from aqueous solutions and wastewaters

Abstract

This first study aims to establish the adsorption capacity of Nigella sativa seeds, an agro-food waste towards Pb(II) according to batch mode by varying contact time, initial Pb(II) concentration, initial pH and sorbent dose. The amount of Pb(II) ion adsorbed at interface is found high in order of 90.31 mg/g under optimum conditions. The FTIR characterization indicates the involvement of the hydroxyl and carbonyl groups of the given material in the adsorption of Pb(II). Isotherm curves and kinetic studies demonstrate that the Langmuir model and pseudo-second order kinetic describe well the sorption phenomenon and fit best to the sorption experimental data. Removing trial of lead from activated sludge waste and its decanted effluent confirm the efficiency of this biomass, which attain 97% and 64% respectively. Based on the results, the Nigella sativa seeds waste biomass appears as a potential eco-friendly and low cost sorbent for sorption of lead from wastewaters.