Biosorption of Cu(II) and Pb(II) ions from aqueous solution by natural spider silk

► Application of SS as a biomaterial for heavy metal biosorption was proposed. ► SS can be used for preconcentration of environmental samples even at acidic medium. ► Sorption kinetics of the SS is fast enough and it is easily applied for column experiments. ► The sorption capacities compete well with biomasses reported. Aside from its excellent mechanical properties, spider silk (SS) would offer an active surface for heavy metal interaction due to its rich protein structure. The present study describes the potential use of natural (SS) as a sorbent of heavy metals from aqueous solutions. Single and multi-species biosorption experiments of heavy metals by natural SS were conducted using batch and column experiments. The biosorption kinetics, in general, was found to follow the second-order rate expression, and the experimental equilibrium biosorption data fitted reasonably well to Freundlich isotherm. From the Freundlich isotherm, the biosorption capacities of Cu(II) and Pb(II) ions onto SS were found as 0.20 and 0.007mmolg–1, respectively. The results showed a decrease in the extent of metal ion uptake with lowering the pH.