caa a22 4500 47705837X CHVBK 20180405111353.0 cr unu---uuuuu 170330e19960901xx s 000 0 eng 10.1007/BF01874903 doi (NATIONALLICENCE)springer-10.1007/BF01874903 A mathematical model for the biosorption of copper on immobilized yeast in alginate [Elektronische Daten] [Yongming Lu, Ebtisam Wilkins] Saccharomyces cerevisiae yeast was entrapped in alginate for the recovery of copper ions from aqueous solution, in which both yeast and alginate could take metal ions. The Freundlich isotherm had been shown to be successful in describing biosorption and a linear biosorption was assumed when the equilibrium copper ion concentration in the fluid was lower than 1 mg/l. The biosorption isotherm was found to be independent of the immobilized yeast densities ranging from 6 to 17 percent. A mathematical model describing the mass transport along with the biosorption was developed with the main assumptions that the inner diffusion with constant diffusivity was the rate limiting step of the biosorption process and the pore solution locally equilibrated with the adjacent biosorbent (both yeast and alginate). This model has theoretical advantages over the formerly proposed Shrinkage Core Model and Linear Adsorption Model. Effective diffusion coefficients of copper ion in immobilized yeast beads using the model developed were found to be independent of the immobilized yeast densities ranging from 6 to 17 percent. The average result was 2.22×10−5 cm2/s. Baltzer Science Publishers BV, 1996 Alginate nationallicence biosorption nationallicence diffusion coefficients nationallicence immobilized yeast nationallicence mathematical model nationallicence C : Copper concentration in the pore of the bead (mg/l) nationallicence C 0 : Initial concentration of copper ion in the reactor (mg/l) nationallicence C b : Copper concentration in the bulk solution (mg/l) nationallicence C ∞ : Final (equilibrium) concentration of free copper in solution (mg/l) nationallicence C 0 : Average copper binding site density of immobilized yeast beads based on biosorption isotherm (mg/l) nationallicence D e : Effective diffusivity of copper ion in the immobilized yeast bead (cm2/s) nationallicence i : Grid point corresponding tor axis nationallicence j : Grid point corresponding tot axis nationallicence m : Grid dimension int axis nationallicence N : Number of immobilized yeast beads in the reactor nationallicence n : Grid dimension inr axis nationallicence Q : Copper concentration in the biomass (mg/g dry mass) nationallicence R : Average radius of the immobilized yeast beads (cm) nationallicence r : Distance from the center of a bead (cm) nationallicence T : Experiment period, (sec) nationallicence t : Time (sec) nationallicence V : Volume of copper ion solution except beads in the reactor (ml) nationallicence X : Dimensionless concentration (C 0−C)/(C 0−C ∞) nationallicence ∈ : Apparent immobilized yeast bead porosity nationallicence ρ : Apparent biomass density (g dry mass/l) nationallicence Lu Yongming Department of Chemical and Nuclear Engineering, University of New Mexico, 87131-1341, Albuquerque, NM, USA aut Wilkins Ebtisam Department of Chemical and Nuclear Engineering, University of New Mexico, 87131-1341, Albuquerque, NM, USA aut Environmental Modeling & Assessment Kluwer Academic Publishers 1/3(1996-09-01), 159-169 1420-2026 1:3<159 1996 1 10666 https://doi.org/10.1007/BF01874903 text/html Onlinezugriff via DOI 1 research-article jats NATIONALLICENCE 856 40 https://doi.org/10.1007/BF01874903 text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Lu Yongming Department of Chemical and Nuclear Engineering, University of New Mexico, 87131-1341, Albuquerque, NM, USA aut NATIONALLICENCE 700 1- Wilkins Ebtisam Department of Chemical and Nuclear Engineering, University of New Mexico, 87131-1341, Albuquerque, NM, USA aut NATIONALLICENCE 773 0- Environmental Modeling & Assessment Kluwer Academic Publishers 1/3(1996-09-01), 159-169 1420-2026 1:3<159 1996 1 10666 Metadata rights reserved Springer special CC-BY-NC licence nationallicence BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-springer