Kinetics of cesium sorption on illite

Reversibility of radiocaesium sorption on illite

“…The apparent irreversibility of radiocaesium sorption as measured by ion exchange has been attributed to the slow migration of caesium into the interlayers of the illite clay mineral, from where it can only be slowly removed (Evans et al, 1983;Comans et al, 1991;Comans and Hockley, 1992). Our present observation that the radiocaesium sorbed after only 5 min is already largely nonexchangeable is inconsistent with this hypothesis, because interlayer migration is a very slow process.…”

“…Sorption of trace amounts of radiocaesium on illitic-type clay minerals in the natural environment has often been described as largely "irreversible," as most of the radiocaesium becomes fixed in the interlayers between the platelets of the minerals (Page and Baver, 1939;Jacobs and Tamura, 1960;Tamura and Jacobs, 1960;Sawhney, 1964;Comans and Hockley, 1992), minimising the transfer of radiocaesium into the ecosystem. However, observations on radiocaesium partitioning in anoxic freshwater sediments (Evans et al, 1983;Comans et al, 1989;Comans, 1999;De Koning et al, 2000) and the persistence of radiocaesium in water, fish, and plants after the Chernobyl accident (Jonsson et al, 1999;Smith et al, 1999;Smith et al, 2000), indicate that radiocaesium sorption must remain at least partly reversible.…”

Episodic deposition and 137Cs immobility in Skan Bay sediments: A ten-year 210Pb and 137Cs time series

“…Cesium sorption by illite is thought to occur at a number of exchange sites (Sawhney, 1972), each having distinct specificity (Cremers et al, 1988) and sorption kinetics (Comans and Hockley, 1992). Since tracer experiments are conducted over time periods of days to weeks, distribution coefficients measured by this approach are relevant to ion exchange at the most accessible sites on the clay particles' exterior surface.…”

Distribution and mobility of137Cs,90Sr,239,240Pu and241Am in solid phase-interstitial soil solution system

“…These cations compete with 137 Cs for FES and increase caesium transfer from solid phase into interstitial soil solution and NFL/ is more selective to FES than K + . In the majority of soils, K + concentration in water phase is much higher than NH/ (Table 2), but in humid soils with poor aeration there are good conditions for generation of NHV and its effect on behavior of 137 Cs significantly increases [3,5].…”