Heavy metal removal from aqueous solution by Pseudevernia furfuracea (L.) Zopf.

The present study was carried out in a batch system using a lichen (Pseudevernia furfuracea (L.) Zopf) for the sorption of nickel(II) and copper(II) ions from water. Particularly, the effect of pH, contact time and temperature were considered. Pseudevernia furfuracea exhibited nickel(II) and copper(II) uptake of 49.87 and 60.83 mg/g at an initial pH of 4 and 5-6 at 35 degrees C respectively. Both the Freundlich and Langmuir adsorption models were suitable for describing the biosorption of nickel(II) and copper(II) by the biosorbent. Biosorption showed pseudo first order rate kinetics for nickel and copper ions. Using the equilibrium constant values obtained at 25 and 35 degrees C, the thermodynamics properties of the biosorption (deltaG degrees, deltaH degrees and deltaS degrees) were determined. The biosorption of nickel(II) and copper(II) onto Pseudevernia furfuracea was found to be endothermic.