Saccharomyces pastorianus immobilized on brewer's spent grain in continuous system for lead ion biosorption

This study investigates the potential application of Saccharomyces pastorianus cells immobilized on brewer's spent grain (BSG) for the removal of lead ions in continuous mode. The effect of initial metal ion concentration on biosorption capacity and the possibility of regeneration and reuse are also assessed. Immobilization of yeast cells on BSG is found to enhance the sorption of lead ions, but only on the first run. Regenerated by washing with 0.05M HCl solution, the biosorbant loses a significant amount of its initial capacity. Degeneration is more severe with higher influent metal concentrations. As a result, the lead ion uptake by yeast immobilized on BSG is not superior to that of BSG alone. These findings reveal that, despite its many potential advantages, yeast immobilized on BSG cannot be recommended for the industrial removal of heavy metal ions from aquatic solutions. (C) 2014 Elsevier Ltd. All rights reserved.