Article

Diffusion kinetic study of cadmium(II) biosorption by Aeromonas caviae

Chemical Technology Division, School of Chemistry, Aristotle University, GR-54124 Thessaloniki, Greece
Journal of Chemical Technology & Biotechnology (Impact Factor: 2.5). 06/2004; 79(7):711 - 719. DOI: 10.1002/jctb.1043
Source: OAI

ABSTRACT The removal of cadmium from aqueous solution by sorption on Aeromonas caviae particles was investigated in a well-stirred batch reactor. Equilibrium and kinetic experiments were performed at various initial bulk concentrations, biomass loads and temperatures. Biosorption equilibrium was established in about 1 h and biosorption was well described by the Langmuir and Freundlich biosorption isotherms. The maximum biosorption capacity was found as 155.32 mg Cd(II) g−1 at 20 °C. The obtained sorption capacity is appreciably high for most experimental conditions; so A caviae may be considered as a suitable biosorbent for the removal of cadmium. Moreover, the sorption rate of cadmium onto A caviae particles was particularly sensitive to initial bulk concentration and solid load. A detailed analysis was conducted, examining several diffusion (external and intraparticle) kinetic models in order to identify a suitable rate expression. The results are discussed and indicate that biosorption of cadmium is a complex process that is described more correctly by more than one model. Copyright © 2004 Society of Chemical Industry

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