Biosorption and extraction of europium by Bacillus thuringiensis strain

Biosorption features of europium on Bacillus thuringiensis biomass have been studied to explore the potential of biomass for extracting Eu3+ from aquatic systems. The adsorption isotherm has been fitted with Langmuir model, the adsorption capacity of Eu3+ achieves as high as 160 mg/g and adsorption kinetics follows pseudo-second order rate model. Additionally, the bacteria exhibit relatively low Eu3+ adsorption characteristics at pH < 4, and the salinity concentration shows no obvious impact on Eu3+ biosorption. The SEM-EDS analysis indicates Eu3+ has been adsorbed on bacterial surfaces. Desorption and recycle experiments demonstrate that Eu3+ could be well desorbed by HCl or EDTA solution, and the bacteria exhibit good regeneration and reusability. These results confirm that the bacteria could be excellent biosorbents for Eu3+. (C) 2016 Elsevier B.V. All rights reserved.