Biosorption Studies for Removal of Cadmium from Wastewater using Immobilized Saccharomyces cerevisiae

Abstract

Biosorption process has been proposed as an efficient, potential, cost effective way of removing toxic metals from industrial effluents at low concentration of below 100 ppm. In the present study a new biosorbent material a waste product from breweries containing yeast, Saccharomyces cerevisiae, was immobilized and was used as an absorbent for removal of cadmium, as yeasts are capable of accumulating various heavy metals. Studies on the removal of cadmium from aqueous solutions using Saccharomyces cerevisiae immobilized in 4% sodium alginate beads were undertaken. Adsorption was carried out using free cells, immobilized beads in presence and absence of biomass. The results indicate that the amount of cadmium adsorbed increases with increase in metal concentration and decreased with decrease in pH. Increase in sodium alginate concentration increased in the metal adsorption. The equilibrium data was fitted to Freundlich type of equation in all cases of present study. Finally an empirical correlation was proposed to estimate the equilibrium distribution of cadmium between immobilized biomass and aqueous solution.