Effect of competitive interference on the biosorption of lead(II) by Chlorella vulgaris

• Published in: Chemical engineering and processing Vol. 46; no. 12; pp. 1391 - 1399
• Main Authors: El-Naas, M.H., Al-Rub, F. Abu, Ashour, I., Al Marzouqi, M.
• Format: Journal Article
• Language: English
• Published: Lausanne Elsevier B.V 01.12.2007; Elsevier
• Subjects: Adsorption; Applied sciences; Biological and medical sciences; Biosorption; Biotechnology; Chemical engineering; Competitive adsorption; Controlling mechanisms; Exact sciences and technology; Fundamental and applied biological sciences. Psychology; Heat and mass transfer. Packings, plates; Lead(II); Methods. Procedures. Technologies; Modeling; Others; Preferential adsorption; Various methods and equipments; Competitive adsorption; Biosorption; Controlling mechanisms; Lead(II); Modeling; Preferential adsorption; Adsorption; Batchwise; pH; Kinetics; Uptake; Mass transfer
• ISSN: 0255-2701; 1873-3204
• DOI: 10.1016/j.cep.2006.11.003

Batch experiments were carried out to asses the effect of Cu(II) and Zn(II) on the biosorption of lead(II) ions by non-living Chlorella vulgaris. The uptake of Pb(II) was examined for single, binary and ternary solutions at different initial concentrations and different pH values. The experimental results showed that the uptake increased with increasing pH from 3.0 to an optimum value of 5.0. The biosorption of Pb(II) was found to be adversely affected by the presence of Cu(II) ions, while Zn(II) ions seemed to have negligible effect on the process. The equilibrium data were fitted to four isotherm models: Langmuir, Freundlich, Sips and Dubinin–Radushkevich; the Sips isotherm gave the best fit for the data. Modeling of the controlling mechanisms indicated that both intrinsic kinetics and mass transfer played major roles in controlling the process. A new dimensionless parameter, Ψ, was defined to asses the relative contributions of the two mechanisms to the biosorption of lead(II). Mass transfer seemed to be the dominant mechanism at low initial lead(II) concentrations, while intrinsic kinetics dominates at high concentrations.