Biosorption of copper(II) ions from aqua solutions using dried yeast biomass

The ability of dried yeast Saccharomyces biomass to remove Cu(II) ions from aqueous solutions was investigated by using of batch techniques. The influence of different parameters on copper uptake by dried yeast, such as initial Cu(II) concentration, initial pH of solution and temperature, was studied. The Freundlich, Langmuir, Redlich–Peterson and Sips isotherms were applied to the obtained experimental data. According to Langmuir isotherm the maximum adsorption capacity of investigated non-living biomass was found to be 2.59 mg/g. The thermodynamic parameters (e.g. free energy and enthalpy) were calculated and discussed. The adsorption of Cu(II) onto the dried cells of Saccharomyces cerevisiae is an endothermic process and become more favorable with the increasing of temperature in pH range from 3 to 4. Optimization studies by means of response surface methodology were carried out, which resulted in improvement of the efficiency of sorption removal by using of biomass. The removal efficiency of real wastewater originating from electroplating industry which contains Sn(II) ions was determined and compared with synthetic wastewater obtained in laboratory.