Effect of various cations upon absorption of carrier-free cesium

Abstract

The effects of the monovalent cations K, Na, NH4, Rb, Li, and Cs and of the divalent cations Ca, Mg, and Baupon the absorption of carrier-free Cs137 by excised barley roots has been investigated. In the concentration range of 0 to 0.10 meq/l Na, Li, Ca, Ba, and Mg had essentially no depressant effect upon Cs137 uptake whereas K, Rb, NH4, and Cs were markedly effective. At higher concentrations all ions investigated inhibited the absorption of Csl37. The uptake of carrier-free Cs137 was found to be strongly temperature dependent and is therefore largely the result of metabolic absorption rather than of diffusion and absorption phenomena. In spite of this the behavior of the ions studied in inhibiting uptake of Cs137 parallels their behavior in respect to competition for exchange sites upon soil colloids. A possible reason for this is discussed.