Contamination of the aqueous environment by heavy metals is a worldwide environmental problem. Biosorption of lead (II) and cadmium (II) from aqueous solutions by brown algae
Sargassum
spp. biomass was studied in a batch system. The heavy metals uptake was found to be rapid and reached to 88-96% of equilibrium capacity of biosorption in 15min. The pseudo second-order and saturation rate equations were found in the best fitness with the kinetic data (
R2 > 0.99). The data obtained from experiments of single-component biosorption isotherm were analyzed using the Freundlich, Langmuir, Freundlich-Langmuir and Redlich-Peterson isotherm models. The Redlich-Peterson equation described the biosorption isotherm of Pb
2+ and Cd
2+ with high correlation coefficient (
R2 0.99) and better than the other equations. The effect of Na
+, K
+, Mg
2+ and Ca
2+ on the biosorption of Pb
2+ was not significant, but the metal ions affected the biosorption of Cd
2+ considerably. According to the Langmuir model, the maximum uptake capacities (qm) of
Sargassum spp. for Pb
2+ and Cd
2+ were obtained as 1.70 and 1.02mmol/g, respectively. Although the
Sargassum spp. used in this study can be classified as an efficient biosorbent.