An overview of the studies about heavy metal adsorption process by microorganisms on the lab. scale in Turkey

Heavy metal ions-namely Cr(VI), Pb(II), Cu(II), Fe(III), Ni(II) and Zn(II)-were removed from synthetic aqueous solutions by using Z. ramigera and R. arrhizus. The adsorption equilibrium data fit both the Langmuir and the Freundlich models. Heavy metal adsorption on free and immobilized cells was also investigated in various reactor types such as stirred tank reactors (single and multi-stage), packed bed and fluidized bed reactors. The multi-component biosorption of Cr(VI), Fe(III), Cu(II), Pb(II) and Ni(II) from binary and ternary mixtures was described, compared to single metal ion situations in solution. The multi-component sorption phenomena were expressed by the competitive adsorption models developed for optimum adsorption conditions.