Adsorption of Ag (I) from aqueous solution by waste yeast: kinetic, equilibrium and mechanism studies

• Published in: Bioprocess and biosystems engineering Vol. 38; no. 1; pp. 69 - 77
• Main Authors: Zhao, Yufeng, Wang, Dongfang, Xie, Hezhen, Won, Sung Wook, Cui, Longzhe, Wu, Guiping
• Format: Journal Article
• Language: English
• Published: Berlin/Heidelberg Springer Berlin Heidelberg 01.01.2015; Springer Nature B.V
• Subjects: Adsorption; Aqueous solutions; Bioengineering; Biotechnology; Chemistry; Chemistry and Materials Science; Environmental Engineering/Biotechnology; Fermentation; Food Science; Hydrogen-Ion Concentration; Industrial and Production Engineering; Industrial Chemistry/Chemical Engineering; Ions; Kinetics; Microscopy, Electron, Transmission; Original Paper; Silver; Silver - metabolism; Solutions; Spectroscopy, Fourier Transform Infrared; Thermodynamics; Waste analysis; Water; Yeast; Yeasts; Yeasts - metabolism; Silver; Kinetics; Waste yeast; Adsorption; Mechanism
• ISSN: 1615-7591; 1615-7605
• DOI: 10.1007/s00449-014-1244-z

One type of biosorbents, brewer fermentation industry waste yeast, was developed to adsorb the Ag (I) in aqueous solution. The result of FTIR analysis of waste yeast indicated that the ion exchange, chelating and reduction were the main binding mechanisms between the silver ions and the binding sites on the surface of the biomass. Furthermore, TEM, XRD and XPS results suggested that Ag 0 nanoparticles were deposited on the surface of yeast. The kinetic experiments revealed that sorption equilibrium could reach within 60 min, and the removal efficiency of Ag (I) could be still over 93 % when the initial concentration of Ag (I) was below 100 mg/L. Thermodynamic parameters of the adsorption process (Δ G , Δ H and Δ S ) identified that the adsorption was a spontaneous and exothermic process. The waste yeast, playing a significant role in the adsorption of the silver ions, is useful to fast adsorb Ag (I) from low concentration.