Adsorption of several actinide (Th, U) and lanthanide (La, Eu, Yb) ions by Mycobacterium smegmatis

Abstract

Adsorption measurements of several actinide [thorium (Th), uranium (U)] and lanthanide [lanthanum (La), europium (Eu), ytterbium (Yb)] cations by Mycobacterium smegmatis showed that sorption kinetics followed a three-phase pattern. For 5% (w/w) bacterial suspensions at pH 1, maximum cation bios0rption per gram dry biomass corresponded to 170 ~tmol Th 4+ and 187 ~tmol UO22+ . Adsorption of all cations studied obeyed the Brunauer-Emmett-Teller isotherm, which assumes multilayer binding at constant energy. Plots for the Scatchard model showed the existence of at least two types of cation complexation site, with strong and weak affinity and negative cooperation. Th 4+ was preferentially adsorbed with respect to the other cations, although all species appeared to compete for the same sites independently of bacterial viability. Adsorption of these cations was accompanied by partial release of magnesium from the cell wall, indicating that exchange reactions occurred at magnesium (Mg)-bonding sites.

Developments in Bioremediation of Soils and Sediments Polluted with Metals and Radionuclides – 1. Microbial Processes and Mechanisms Affecting Bioremediation of Metal Contamination and Influencing Metal Toxicity and Transport

“…Gadd and White (1989), however, noted that more complex interactions are difficult to model because the adsorption of solutes by solids is affected by factors including diffusion, heterogeneity of the surface and pH. An additional isotherm, the BrunauerEmmett-Teller (BET) isotherm, which assumes multilayer binding at constant energy has also been used to describe metal biosorption (de Rome & Gold 1991;Andres et al 1993). This model assumes that one layer need not necessarily be completely filled before another is commenced.…”

“…This model assumes that one layer need not necessarily be completely filled before another is commenced. Further insight is offered by Andres et al (1993), who summarize that each adsorption layer of the BET model can be reduced to Langmuir behavior with homogeneous surface energy, in contrast to the adsorption energy requirements of the Freundlich isotherm. Other studies have used complex multistage kinetic approaches to model biosorption (Weidemann et al 1981;Treen-Sears et al 1984).…”

A DFT study on the interaction between europium, uranium and SWCNT

“…In the past twenty years, extensive studies have researched the treatment of radioactive waste. Yves Andres investigated the adsorption of several actinide (Th, U) and lanthanide (La, Eu, Yb) ions by a biological method [17]. C.L.…”

Microorganisms effects on radionuclides migration

“…The presence of glutamate, sulphate, phosphate, carbonate, chloride and ethylenediaminetetraacetate (EDTA) in solution with metal / complexant ratios up to 15, affects the biosorption of lanthanum by a Rhizopus arrhizus biomass [28]. Furthermore, the biosorption of lanthanum by Mycobacterium smegmatis is greatly decreased by the presence in solution of thorium or uranyl ions at pH 1.0 [13]. Karavaiko et at.…”