Physicochemical Mechanisms of Dissolved 137Cs Seasonal Variations in Freshwaters: Fukushima and Chernobyl.

Analysis of available monitoring data sets on concentrations of accidentally derived dissolved radiocesium in water bodies is indicative of two major physicochemical mechanisms responsible for their seasonal variations in water bodies in the course of the year: temperature dependence of radiocesium desorption from suspended material and ion-exchange remobilization of radiocesium by ammonium cations formed during decomposition of organic matter in anoxic conditions. An equation describing seasonal variations in concentration of dissolved radiocesium in water bodies has been derived accounting for two factors: water temperature, and combined concentration of key competing cations. [ABSTRACT FROM AUTHOR]