Uses of Ramalina sinensis and Umbilicaria americana lichens in the removal of Pb2+ from contaminated waters

Heavy metals such as lead are a cause of environmental pollution because of their high degree of toxicity and are is the important problem of today s world. The uses of Pb2+ from contaminated waters cause cancer disease as well as biological accumulation in the cells of living organisms. Up to now, the expensive and high costs methods such as chemical precipitation, ion exchange, adsorption, membrane processes and redox processes were used for removing of heavy metals. In this study, natural sources such as Ramalina sinensis and Umbilicaria americana lichens were investigated in the removal of Pb2+ from aqueous solutions utilizing Response syrface Methodology. The results showed, in optimum condition, the removal efficiency of Pb2+ from contaminated waters was more than 95%. So, the lichens have a good ability in the removal of Pb2+.