Heavy-metal adsorption by non-living biomass |
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Authors: | M A Shaker H M Hussein |
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Institution: | 1. Physics &2. Chemistry Department, Faculty of Education , Alexandria University , Damanhour, Egypt drmshaker@yahoo.com;4. Institute of Genetic Engineering and Biotechnology, Mubarak City for Scientific Research and Technology , Alexandria, Egypt |
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Abstract: | The adsorption of some heavy metals onto the walls of harvested, washed, and dried non-living biomass cells of different Pseudomonas strains was studied at optimum experimental conditions using a simplified single component system. The Langmuir adsorption model was found to be a suitable approach to describe the system via multi-step processes. Isotherms measured at 30.0°C and pH 5.5 with M]total?=?10–100 mM for tight, reversible Cr6+(aq), Ni2+(aq), Cu2+(aq) and Cd2+(aq) binding by the cell walls of the investigated biomass fit the Langmuir model and give the pH-independent stoichiometric site capacities ν i and equilibrium constants K i for metal binding at specific biomass sites i?=?A, B, C, and D. Tight binding sites A, B, and D of the non-living biomass are occupied by CrVI, sites A and C by NiII, sites A and D by CdII, and only site B by CuII. It is concluded that ν i is a stoichiometric parameter that is independent of the magnitude of K i for binding site i and that the studied heavy metals selectively and tightly bind at different biomass sites. |
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Keywords: | Adsorption Langmuir Isotherm Heavy metals Non-living biomass Binding sites |
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