Bioaccumulation of silver‐110m, cobalt‐60, cesium‐137, and manganese‐54 by the freshwater algae Scenedesmus obliquus and Cyclotella meneghiana and by suspended matter collected during a summer bloom event

Abstract

Bioaccumulation of silver-110m, cobalt-60, cesium-137, and manganese-54 by the freshwater algae Scenedesmus obliquus and Cyclotella meneghiana and by suspended matter collected during a summer bloom event ). However, Cs accumulation and depuration were very slow, with kinetic constants of 0.6-5 d Ϫ1 . Mn, Co, and Ag were more strongly accumulated by C. meneghiana than S. obliquus and vice versa for Cs. To evaluate the extrapolation of the kinetic rates fitted for S. obliquus and C. meneghiana to natural conditions, suspended solids were also collected during a bloom event and contaminated. Radionuclide exchange between three distinct compartments among the suspended solids was modeled: the kinetic rates fitted for S. obliquus and C. meneghiana were used to represent chlorophyte and bacillariophyte contamination, whereas kinetic rates describing a third compartment were estimated when possible. A third compartment was evidenced only for Mn and Co, whereas, for Ag, the chlorophyte and bacillariophyte compartments were sufficient to describe the particulate phase. For Cs, algae kinetic rates could not be used, so a single compartment was fitted. These experiments confirm the low affinity of Cs for phytoplankton and the high bioavailability of Ag. In the case of Co and Mn, several processes acting simultaneously govern the contamination of natural suspended solids.

An extremely radioresistant green eukaryote for radionuclide bio-decontamination in the nuclear industry

“…64 Silver also belongs to the highest toxic class of heavy metals with cadmium, surpassed only by mercury. 65,66 Values obtained in this work are among the upper values of the wide range of BCFs reported for these elements in microalgae, namely 1700-400 000 mL g À1 FW for silver 30,31,67 and 300-3300 mL g À1 FW or 40 000 mL g À1 dry weight (DW) for radiocobalt. 30,68,69 In 24 h, C. actinabiotis completely removed 110m Ag, 65 Zn, and 137 Cs from nuclear effluents and xed more than 90% of 60 Co, 58 Co, 54 Mn, and 238 U ( Table 1).…”

Adsorption of Radionuclides (134Cs, 85Sr, 226Ra, 241Am) by Extracted Biomasses of Cyanobacteria (Nostoc Carneum, N. Insulare, Oscillatoria Geminata and Spirulina Laxis-Sima) and Phaeophyceae (Laminaria Digitata and L. Japonica; Waste Products from Alginate Production) at Different pH

“…The non-phosphorylated cyanobacterial and Laminaria biomasses removed smaller amounts of the monovalent 134 Cs + than of the divalent cations 85 Sr ++ and 226 Ra ++ . Poor adsorption of 134 Cs by marine algae and picoplankton, in comparison with adsorption by divalent radionuclides, has also been reported by Fisher (1985), Boisson et al (1997), Heldal et al (2001) and Adam and Garnier-Laplace (2003). This is likely to be because the equilibrium constants of complexes of divalent cations with carboxylic acids are larger by orders of magnitude than those of monovalent cations (Pohlmeier, 1999).…”

“…This can be achieved by membrane technologies, but the results reported here indicate that use of adsorbing materials is also a possibility. Moderate RN concentrations have also been used in investigations reported by others, for example investigations into the bioaccumulation of some RN by two freshwater algae by Adam and Garnier-Laplace (2003) and by Boisson et al (1997). The radiation from high RN concentrations can alter the biomass structure.…”

Psychrophilic and Psychrotolerant Microbial Extremophiles in Polar Environments

“…(Absil and van Scheppingen, 1996). Adam and Garnier-Laplace (2003) Mn) by the diatom Cyclotella meneghiana and the chlorophyte Scenedesmus obliquus. Some species of diatoms and oscillatorian cyanobacteria have been shown to be able to partially oxidize hydrocarbons such as naphthalene, biphenyl when grown phototrophically (Cerniglia et al, 1980).…”