African Journal of Biotechnology Vol. 4 (6), pp. 506-508, June 2005          
ISSN 1684–5315 © 2005 Academic Journals

Short Communication

Biosorption of zinc (II) by Rhizopus arrhizus: equilibrium and kinetic modelling

B. Preetha* and T. Viruthagiri

Department of Technology, Annamalai University, Annamalai Nagar- 608 002.Tamil Nadu, India.

*Corresponding Author E-mail: eeprthapar@yahoo.co.in.

Accepted 10 May, 2005

The adsorption of zinc (II) ions on Rhizopus arrhizus, a filamentous fungus, was investigated in a batch reactor. Batch adsorption studies were carried out by varying biomass loading. A contact time of 120 min was required to reach equilibrium. Specific zinc (II) uptake decreased with increase in biomass loading and these results were analyzed in light of the Lagergren equation and the process followed a second order rate kinetics. The equilibrium data were analyzed using the Langmuir, Freundlich, Redlich- Peterson and BET adsorption isotherms. The characteristic parameters for each isotherm were determined. All the isotherms provided the best correlation for zinc (II) onto the R. arrhizus.

Key words: Zinc, biosorption, Rhizopus arrhizus, kinetic models, adsorption isotherms.