Effect of various cations upon absorption of carrier-free cesium

Abstract

The effects of the monovalent cations K, Na, NH/sub 4/, Rb, Li, and Cs and of the divalent cations Ca, Mg, and Ba upon the absorption of carrier-free Cs/ sup 137/ by excised barley roots have been investigated. In the concentration range of 0 to 0.l0 meq per liter Na, Li, Ca, Ba, and Mg had essentially no depressant effect upon Cs/sup 137/ uptake whereas K, Rb, NH/sub 4/, and Cs were markedly effective. At higher concentrations all ions investigated inhibited the absorption of Cs/sup 137/. The uptake of carrier-free Cs/sup 137/ was found to be strongly temperature dependent and is therefore largely the result of metabolic absorption rather than of difiusion and adsorption phenomena. In spite of this the behavior of the ions studied in inhibiting uptake of Cs/sup 137/ parallels their behavior in respect to competition for exchange sites upon soil colloids. A possible reason for this is discussed. (auth)