[Biosorption of heavy metals by bacteria isolated from activated sludge]

In this paper, biosorption efficiency of heavy metals by bacteria isolated from activated sludge was tested. It was shown that Pseudomonas pseudoalcaligenes and Micrococcus luteus GC subgroup B had high biosorption capacities for Cu(II) and Pb(II) ions. The adsorption of the two ions on Pseudomonas pseudoalcaligenes and Micrococcus luteus GC subgroup B exhibited Langmuir adsorption behavior with regression coefficient of 0.99. The pH value was the most important effect factor on biosorption of metal ions. The biosorption kinetic curves of Cu(II) and Pb(II) ions by cells showed two processes: rapid sorption on cell surface and slowly longer-term transformation into cells. Cu(II) ion can be desorbed effectively from cells of Micrococcus luteus GC subgroup B.