Author(s): Kazem Naddafi | Ramin Nabizadeh | Reza Saeedi
Journal: Pakistan Journal of Biological Sciences
ISSN 1028-8880
Volume: 8;
Issue: 9;
Start page: 1250;
Date: 2005;
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Keywords: Biosorption | Sargassum | lead (II) | cadmium (II) | kinetic
ABSTRACT
Biosorption kinetics of lead (II) and cadmium (II) from aqueous solutions by Sargassum sp. biomass were studied. Kinetic experiments were done in three initial concentrations of Pb2+ and Cd2+ and fixed initial ratio of adsorbate to biosorbent in single component batch system. The heavy metals uptake was found to be rapid for all concentrations and reached to 88-96% of equilibrium capacity of biosorption in 15 min. Monitoring of pH in the kinetic experiments presented the simultaneous release of H+ with the uptake of Pb2+ and Cd2+, therefore ion exchange was confirmed to be one of the biosorption mechanisms. The experimental data were analyzed using four sorption kinetic models; the pseudo first-order (Langergren), pseudo second-order, saturation (mixed-order) and second-order rate equations. The pseudo second-order and saturation rate equations described the biosorption kinetics of Pb2+ and Cd2+ with high correlation coefficient (R2>0.99) and better than the other equations. Kinetic analysis presented a direct relationship between initial Pb2+ and Cd2+ concentrations and the rate of biosorption. The maximum uptake capacities of Sargassum sp. biomass for Pb2+ and Cd2+ were obtained 1.07 and 0.79 mM g-1, respectively.
Journal: Pakistan Journal of Biological Sciences
ISSN 1028-8880
Volume: 8;
Issue: 9;
Start page: 1250;
Date: 2005;
VIEW PDF
DOWNLOAD PDF Original pageKeywords: Biosorption | Sargassum | lead (II) | cadmium (II) | kinetic
ABSTRACT
Biosorption kinetics of lead (II) and cadmium (II) from aqueous solutions by Sargassum sp. biomass were studied. Kinetic experiments were done in three initial concentrations of Pb2+ and Cd2+ and fixed initial ratio of adsorbate to biosorbent in single component batch system. The heavy metals uptake was found to be rapid for all concentrations and reached to 88-96% of equilibrium capacity of biosorption in 15 min. Monitoring of pH in the kinetic experiments presented the simultaneous release of H+ with the uptake of Pb2+ and Cd2+, therefore ion exchange was confirmed to be one of the biosorption mechanisms. The experimental data were analyzed using four sorption kinetic models; the pseudo first-order (Langergren), pseudo second-order, saturation (mixed-order) and second-order rate equations. The pseudo second-order and saturation rate equations described the biosorption kinetics of Pb2+ and Cd2+ with high correlation coefficient (R2>0.99) and better than the other equations. Kinetic analysis presented a direct relationship between initial Pb2+ and Cd2+ concentrations and the rate of biosorption. The maximum uptake capacities of Sargassum sp. biomass for Pb2+ and Cd2+ were obtained 1.07 and 0.79 mM g-1, respectively.
