S Hosseini - Department of Chemical and Petroleum Engineering Sharif Univerisity of Technology, Tehran, Iran
M .soleimani - Department of Chemical and Petroleum Engineering Sharif Univerisity of Technology, Tehran, Iran
R .Roostaazad - Department of Chemical and Petroleum Engineering Sharif Univerisity of Technology, Tehran, Iran
S.M Mousavi - Department of Chemical and Petroleum Engineering Sharif Univerisity of Technology, Tehran, Iran. Department of Chemical Technology, Lappeenranta University of Technology, Lappeenranta, Finland.

The Zn2+ biosorption capacity of the two type of bacteria(Pseudomonas putida, Streptomyces rimosus) and two type of fungi(Phanerochaete chrysosporium Aspergillus niger)biomasses pretreated with NaOH and also in living cell condition studied in the batch mode. Comprehensive experiments were studied as functions of reaction time, initial pH of the solution, initial metal concentration and biosorption kinetics. Phanerochaete chrysosporium exhibited higher capacity of zinc biosorption ,than other microbes, i.e. 72.3(mg/g) for pretreated with NaOH cells and 41.4(mg/g)for living cells, at the optimal condition. The maximum zinc biosorption of zinc for all cases ,about 5-6. Pretreating cells with NaOH showed significant influences in the biosorption capacity, wich 1.2-2.5 times more than living cells. At the optimal conditions, metal ion biosorption was increased as the initial metal concentration increased. The adsorption data provide an excellent fit to the Langmuir isotherm for all cases except of Streptomyces rimosus and kinetic data were properly fitted with the pseudo-secondorder kinetic model for kind of biosorbant experimented.

Biosorption , Four microbes ,Isotherms , kinetics , Pretreated , Zinc