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

Abstract

The extracted biomasses of four cyanobacteria (Nostoc carneum, Nostoc insulare, Oscillatoria geminata, and Spirulina laxissima) grown in axenic mass cultures, and of four samples of Laminaria obtained from different locations (L. digitata I and II, France; L. japonica I and II, China; all waste products from alginate production) were tested for their ability to adsorb four radionuclides ( 134 Cs, 85 Sr, 226 Ra, and 241 Am) under different pH regimes. In addition, two of the cyanobacterial biomasses (N. carneum and O. geminata) and the four Laminaria biomasses were phosphorylated before being tested as radionuclide adsorbers. The non-phosphorylated cyanobacterial biomasses showed very low adsorption of 134 Cs but substantially higher removal of 85 Sr and 226 Ra, which increased with increasing pH. 241 Am was almost completely removed from the solution at low pH, but less at higher pH. After phosphorylation, removal of 134 Cs, 85 Sr and 226 Ra by the cyanobacterial biomasses was improved, particularly at lower pH, but there was almost no adsorption of 241 Am. The non-phosphorylated P. Pohl ( ) Laminaria biomasses showed good removal of 134 Cs and very good adsorption of 85 Sr and 226 Ra. Removal of 241 Am was high at low pH but decreased with increasing pH. After phosphorylation, adsorption of 134 Cs by Laminaria samples was slightly improved; removal of 85 Sr and 226 Ra was increased at low pH with a tendency towards decrease in adsorption with increasing pH; but almost no 241 Am was adsorbed. The origin of the cyanobacterial and Laminaria materials appeared to have little effect on the adsorption of the radionuclides.

Potential use of algae for heavy metal bioremediation, a critical review

“…Biosorption of heavy metal ions in wastewater using algae can offer an ecologically safer, cheaper, and more efficient means to remove metal ions from wastewater. Indeed algae can be used for sorption of toxic and radioactive metal ions [17], and also to recover precious metal ions like gold and silver [18,19].…”

Selective Uptake of Alkaline Earth Metals by Cyanobacteria Forming Intracellular Carbonates

“…24 Several organisms able to trap Sr and/or Ba have been discovered, including some bacteria, micro-algae and plants. 11,[25][26][27][28][29][30][31][32][33][34][35] Different mechanisms of sequestration may be involved. First, Sr 2+ and Ba 2+ may be adsorbed on the cell surface.…”

Global searches for microalgae and aquatic plants that can eliminate radioactive cesium, iodine and strontium from the radio-polluted aquatic environment: a bioremediation strategy

“…In algae, the brown alga Laminaria digitata adsorbed more than 80 % of 134 Cs under high pH conditions when the membrane was phosphorylated artificially (Pohl and Schimmack 2006). In this study, we found that the eustigmatophycean alga nak 9 could eliminate more than 90 % of radioactive Cs without any special treatment (Figs.…”

“…PCC6803, an extracellular hemolysin-like protein (HLP) conjugate with polysaccharides functions to adsorb 109 Cd very rapidly (in a minute-order time course) (Sakiyama et al 2011). In N. commune , the absorption of 85 Sr into the cells is increased by phosphorylation on the cell surface (Pohl and Schimmack 2006). In terrestrial plants, sunflower is able to entirely absorb 150 μg Sr in 100 h when grown in radio-polluted water (Dushenkov et al 1997).…”