Removal of 60Co2+ and 137Cs+ ions from low radioactive solutions using Azolla caroliniana willd. water fern

Abstract

This study concerns the removal of the 137 Cs + and 60 Co 2+ β + γ− radioactive ions in Azolla caroliniana Willd. water fern. The living fern and two different types of biosorbent prepared from Azolla caroliniana were tested to remove the above-mentioned radioactive ions from dilute solutions, in the absence and in the presence of the ionic competition. Effective 137 Cs + and 60 Co 2+ ions removal from low radioactive wastewaters was demonstrated. The time-dependent K d (t) values were calculated from the absorption data. These results indicate that removal process achieved equilibrium in about 120 min and that it involves two steps: rapid and slow absorption; the active process (metabolic bioaccumulation on the living fern) was responsible for above one half of the total removal process. A thin layer radiochromatography study leads to the conclusion that the biochemical components in which 137 Cs + and 60 Co 2+ place themselves are of a polysaccharide and lipoid fractions.