Reusability of immobilised Saccharomyces cerevisiae with successive copper adsorption-desorption cycles

Immobilised Saccharomyces cerevisiae in batch reactors effectively removed copper from solution with a binding equilibrium of 70% being attained within 20 minutes of contact. Maximum uptake was between pH 3 to 5 (V sub(max) = 24.1 mu mol/g) and was substantially reduced at pH 2. Bound copper was readily recovered by addition of 1.0 M HCl ( less than or equal to 2 % v/v). In adsorption-desorption studies metal removal and recovery was high, and uptake was increased with repeated use. Electron microscopy confirmed that no morphological changes occur to the cells during repeated adsorption-desorption.