Biosorption of lead(II) from aqueous solution by cone biomass of Pinus sylvestris

Biosorption of lead (II) onto a cone biomass of Pinus sylvestris was studied with variation in the parameters of pH, initial metal ion concentration and impeller speeds. Lead removal rate was increased at pH 4.0 and was sharply decreased when pH of the solution was decreased to 2.0. Impeller speed studies indicated maximum lead biosorption at 150 rpm and the biosorption equilibrium was established after about 1 h. The adsorption constants were found from the Freundlich isotherm at 25degreesC. An increase in lead/biomass ratio caused a decrease in biosorption efficiency. The cone biomass, which is a readily available biosorbent, was found suitable for removing of lead in aqueous solution.