Packed bed redistribution system for Cr(III) and Cr(VI) biosorption by Saccharomyces cerevisiae

Saccharomyces cerevisiae yeast was immobilized on residual pumice for trivalent and hexavalent chromium solution adsorption inside a PVC column of 4.3 cm diameter, 140 cm length by using a novel redistribution system. Metallic solutions were fed through the packed bed column in order to establish breakthrough curves, inlet solution conditions were 300 mg/L and 200 mg/L for Cr(III) and Cr(VI) respectively, pH value for Cr(III) was 4.3 and 1.66 for Cr(VI), the effluent solution was analyzed at equal time intervals, obtaining breakthrough points of 240 min for Cr(III) and 300 min for Cr(VI). It was found that redistribution system for chromium removal by Saccharomyces cerevisiae increases contact sites between yeast and metallic ion due to liquid flow ability through the column and the results were better if compared with a fixed column without redistribution. Removal percentages of 53.7% and 60% for Cr(III) and Cr(VI) respectively were obtained.

► Biosorption is a popular and effective technique for metal recovery from wastewaters.
► Saccharomyces cerevisiae increases contact sites between yeast and metallic ion.
► A packed bed adsorption column with immobilized biomass offer an easy scale up.
► The efficiency of a packed bed is highly dependent on liquid distribution.