خسرو محمدی

The biosorption of lead by Sargassum (1) as brown alga and Entromorpha (2) as green alga are studied. The role of effecting parameters such as initial metal ion concentration, temperature, pH, and contact time and biosorbent dose on the lead (II) biosorption were treated. The maximum of lead uptake for 0.2 g of biomass, 150 mg/L initial metal ion concentration and 45 °C, and for Sargassum (1) are obtained in pH = 5 and contact time = 55 minute and for Entromorpha (2) are obtained in pH = 6 and contact time = 60 minute . The kinetics of biosorption for both algae are fitted by pseudo second order model. The adsorption isotherms are studied by Freundlich, Langmuir, Freundlich-Langmuir and Temkin models. Design of the experiment is arranged for prediction of the role of the cooperating parameters on biosorption by using the response surface methodology.