Uranium and thorium uptake on hydrophilic plants

The hydrophilic plants were used with the purpose of purifying the radioactive waters containing UO22+ and Th4+ ions. The efficiency of using these plants, rendering by the degree of uptake (bioaccumulation and biosorption) of these plants in the absence of ionic competition was studied in the case of radioactive effluents simulated by UO2(NO3)2 and Th(NO3)4 solutions. Under identical experimental conditions, the degree of decontamination of radioactively wastewater decreases according to the following series: Riccia fluitans > Lemna minor > Pistia stratiotes > Elodea canadensis. The influence of certain environmental factors (like temperature, pH, anion nature, etc.) was studied in order to optimize the process. A thin layer radiochromatography study leads to the conclusion that the biochemical fractions in which UO2 2+ and Th4+ place themselves are of a polysaccharide and lipoid fractions.