Biosorption of strontium by Padina sp. algae biomass: process optimisation and equilibrium study

Abstract

Biosorption of strontium by Padina sp. algae from aqueous solutions was studied. A response surface methodology (RSM) was employed to optimise the biosorption parameters. The effects of pH, initial metal concentration in solution, biomass dosage and temperature on the strontium uptake by the algae were investigated. RSM analysis showed that the experimental data were adequately fitted to second-order polynomial model. The parameters with significant effect on the removal of strontium using the algae were determined. The optimum parameters within the experimental range of the variables were 9.50, 4.00 mmol/l, 1.11g/l and 30oC for pH, initial metal concentration, biomass dosage and temperature, respectively. Under such condition, the strontium uptake was predicted to be 248.10 mg/g. The equilibrium data were analysed in terms of Langmuir, Freundlich and Sips isotherms. The data fitted well to the Sips model. The maximum uptake estimated by the Sips model was 269.92 mg/g.