Lead removal from aqueous solutions by natural Greek bentonites

batch study has been performed to investigate the adsorption characteristics of lead ions (Pb2+) onto natural bentonite samples. The effect of various physicochemical factors that influence adsorption, such as solution pH (26), adsorbent dosage (110 g L1), contact time (20360 min), and initial metal ion concentration (5150 mg L1) was studied. A number of available models like the Lagergren pseudo first-order kinetic model, the pseudo second-order kinetic model and intra-particle diffusion were utilized to evaluate the adsorption kinetics. The adsorption of Pb2+ was modelled with the Langmuir, Freundlich and D-R isotherms. The maximum Pb2+ adsorption capacities for B1, B2 and B3 were 85.47 mg g1, 73.42 mg g1 and 48.66 mg g1, respectively