Biosorption studies for removal of metals from aqueous solution using immobilized freshwater alga spirulina platensis

The main aim of this study is to screening the potential of freshwater alga Spirulina platensis to remove Cr, Fe, Mn and Se from aqueous solution. The effects of initial metal concentrations, pH and algal biomass dose on metal biosorption were investigated. The results shows that the increase in an initial concentrations of Mn, Fe, Cr and Se led to decrease in the percentage of removal for all the metals, also it was observed that as the dose of algal biomass increases the amount of metal removed decreases. The maximum uptake for Mn, Fe, Cr and Se was found to be at 0.025 gm of algal biomass dose. The initial pH of the metal solution is an important parameter affecting the biosorption of metal ions. The effect of pH on metal biosorption has been studied, and the results indicated that the pH value of solution could significantly influence the biosorption. A trend of increasing metal ion binding with increasing pH could be observed for all the metals. The optimal removal efficiencies of all the metals were observed at the pH 6. The maximum uptake at pH 6 and initial metal concentration of 5 mg/L, for Mn, Fe, Cr and Se using immobilized cells of Spirulina platensis observed as 4.97 mg/L, 4.99 mg/L, 4.99 mg/L and 4.98 mg/L after 24 hours of incubation period.