Biosorption of zinc and copper ions by immobilized yeast under aerobic and anaerobic conditions

Abstract

Studies have been conducted to evaluate the efficiency of biosorption of zinc and copper ions by brewing yeast Saccharomyces cerevisiae immobilized on alginates. The studies were carried out under aerobic and anaerobic conditions using calcium, calcium, magnesium, and aluminum alginates. Under aerobic conditions, when live yeast was immobilized in calcium alginate, the concentration of zinc ions in an aqueous solution decreased within 2 hours by 99.76%, and copper ions by 91.7%. Biosorbents based on a mixture of calcium and magnesium alginates work less effectively (reducing the concentration of zinc ions by 99.3%, and copper ions by 75.8%). Under anaerobic conditions, a biosorbent based on calcium alginate decreased its efficiency in the presence of zinc ions by 0.8%, and that based on aluminum alginate - by 5.4%. In the presence of copper ions, the biosorption efficiency under anaerobic conditions decreased by 2.1%–9.9%, depending on the alginate. This work demonstrates the potential of the brewing yeast Saccharomyces cerevisiae as a calcium alginate-based biosorbent.