Biosorption of cobalt (II) by Inta ct and Chemically Modified Brown Algae: Optimization Using Resp onse Surface Methodology and Equilibrium, Dynamics and Thermodynamics Studies

Soleymani, F.; Pahlevanzadeh, H.; Khani, M.H.; Manteghian, M.

Biosorption of cobalt (II) by Inta ct and Chemically Modified Brown Algae: Optimization Using Resp onse Surface Methodology and Equilibrium, Dynamics and Thermodynamics Studies

Document Type : Full article

Authors

F. Soleymani ¹

H. Pahlevanzadeh ¹

M.H. Khani ²

M. Manteghian ¹

¹ Chemical Engineering Department, Tarbiat Modares University, Tehran, Iran

² Nuclear Fuel Cycle Research School, Nuclear Science and Technology Research Institute, Tehran, Iran

Abstract

By using response surface methodology, Batch shaking biosorption of cobalt (II) experiments were conducted in order to examine the combined effects of operating parameters. The results indicate that magnesium nitrate performed as an effective biosorbent surface modifier, which increases the rate of adsorption capacity. At optimal conditions (initial pH 7.0, temperature 45◦C, biosorbent concentration 0.1 g/100ml, and initial cobalt concentration 300mg/l for Mg-treated biomass) the biosorption capacity of the algae for cobalt was found to be 80.55 mg/g. The Langmuir and Freundlich isotherms were applied to the equilibrium data. The results are best fitted by the Freundlich model. Evaluation of the experimental data in terms of biosorption dynamics showed that the biosorption of cobalt (II) onto algal biomass followed the pseudo-second-order dynamics well. Using the thermodynamic equilibrium coefficients obtained at different temperatures, the thermodynamic parameters (ΔG◦, ΔH◦ and ΔS◦) were also evaluated.

Keywords

Biosorption

Response Surface Methodology

Pretreated Algae

Cobalt

Sargassum sp