SOLID-PHASE SPECIATION OF RADIOCESIUM IN BOTTOM SEDIMENTS

A comprehensive laboratory study is presented on the solid-phase speci ation of ionic radiocaesium in bottom sediments (riverine, lacustrine, estuarine) covering some 75 samples of widely differing textural prop erties and originating from various locations in Europe. Sediments are characterised in terms of cation exchange capacities, exchangeable po tassium and ammonium and specific radiocaesium sorption properties. It is shown that radiocaesium is quantitatively retained in the specific sorption sites associated with the micaceous clay minerals in the sed iments. The practical consequences of this finding are discussed in te rms of a predictive equation allowing forecasting of radiocaesium leve ls in the watercolumn or in the interstitial fluid of the sediment.