Biosorption of cadmium by live and dead Spirulina: IR spectroscopic, kinetics, and SEM studies.

Cadmium is an important environmental pollutant and a potent toxicant to bacteria, algae, and fungi. Mechanisms of Cd+2 toxicity and resistance are variable, depending on the organism. The present work reports the use of live and dead Spirulina sp. for sorption of Cd+2. This investigation shows that this biomass takes up substantial amount of Cd+2 ions. IR spectroscopic study, kinetics models, Langmuir & Freundlich adsorption isotherms, scanning electron microscopic analysis of Spirulina sp., and the Spirulina sp. treated with different metal ions have been employed to understand the sorption mechanism. Infrared spectra of live Spirulina treated with Cd+2 ions for different lengths of time have been taken to understand the time dependency of metal interaction.