Biosorption of uranyl ions from aqueous solution by Saccharomyces cerevisiae cells immobilized on clinoptilolite

This study deals with the uptake of uranyl ions from aqueous solution using bio-modified natural clinoptilolite. The biosorption experiments were carried out in a batch system. Cell immobilization process and sorption of uranyl ions were confirmed by scanning electron microscopy and inductively coupled plasma-optical emission spectroscopy techniques, respectively. The adsorption equilibrium was reached in 4 h, the optimum pH was 4.5 and the temperature had no significant effect on the uranyl biosorption. The experimental data were well fitted with Langmuir isotherm and pseudo-second-order kinetic models. The maximum sorption capacity of cell immobilized clinoptilolite was 0.148 mmol (UO22+) g(-1) dry sorbent.