Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
583868 | Journal of Hazardous Materials | 2007 | 7 Pages |
Abstract
Biosorption of lead(II) and cadmium(II) from aqueous solutions by protonated Sargassum glaucescens biomass was studied in a continuous packed bed column. The selective uptake of Pb2+ and Cd2+ was investigated in a binary system with initial concentration of 1Â mM for each metal ion. The selective uptake capacities of Pb2+ and Cd2+ at complete exhaustion point were obtained 1.18 and 0.22Â mmol/g, respectively; therefore, the biosorbent showed much higher relative affinity for Pb2+ than for Cd2+. The optimum range of empty bed contact time (EBCT) was identified as 5-10Â min in the packed bed column. The efficiency of biosorbent regeneration by 0.1Â M HCl was achieved about 60%, so that the maximum uptake capacity of Pb2+ by the regenerated biomass was determined to be 0.75Â mmol/g while the same value for the original biomass was 1.24Â mmol/g. The Thomas model was found in a suitable fitness with the experimental data (R2Â >Â 0.90 and É%Â <Â 50%) at all different operation stages. Monitoring of pH in the effluent of the column presented the simultaneous release of H+ with the uptake of heavy metals; hence, ion exchange was confirmed to be one of the main biosorption mechanisms.
Keywords
Related Topics
Physical Sciences and Engineering
Chemical Engineering
Chemical Health and Safety
Authors
Kazem Naddafi, Ramin Nabizadeh, Reza Saeedi, Amir Hossein Mahvi, Forough Vaezi, Kamyar Yaghmaeian, Azar Ghasri, Shahrokh Nazmara,