Radioactive fallout Cs (cesium-137) deposited across the landscape from atmospheric nuclear tests is strongly absorbed on soil particles limiting its movement by chemical and biological processes Most Cs movement in the environment is by physical processes; therefore, Cs is a unique tracer for studying erosion and sedimentation Cesium-137 loss from a watershed has been shown to correlate strongly with soil loss calculated by the Universal Soil Loss Equation (USLE) or measured from small runoff plates By measuring spatial patterns of Cs in vertical and horizontal planes across the landscape, rates of soil loss or deposition can be measured for different parts of a watershed Even within landscape units, redistribution of soil can be mapped and erosion or deposition rates for different parts of individual fields measured and mapped Sediment accumulation rates can be measured by comparing the vertical distribution of Cs in sediments with the temporal deposition of fallout Cs from the atmosphere to locate sediment horizons Using these dated sediment horizons, sediment accumulation rates can be measured Interpretations about the location of these dated horizons must consider particle size of the sediments, reworking of deposited sediments, diffusional movement of Cs, and time rates of physical process in the sedimentation process The Cs technique can be used to determine sediment accumulation rates in a wide variety of depositional environments including reservoirs, lakes, wetlands, coastal areas, and floodplains The bibliography shows that Cs has been used widely for studying erosion and sedimentation in many different environments around the world

Application of Radioactive Fallout Cesium-137 for Measuring Soil Erosion and Sediment Accumulation Rates and Patterns: A Review

The adsorption behavior of cesium on pure minerals is reviewed. Although this field has been investigated intensively, the data are extremely variable in scope and interpretation with detailed information being available for only a few minerals. In current investigations in this field, the emphasis is on the nature of the adsorption sites and identification of these sites using spectroscopic techniques. In the first section of this review, the general mechanism of cesium adsorption is discussed and this is followed by consideration of the effect of parameters such as cesium concentration, the properties of the mineral and the characteristics of the solution phase, on cesium adsorption. Finally, interaction of cesium with some different minerals is described in some detail.

Adsorption of cesium on minerals: A review

Major and trace elements of river-borne material: The Congo Basin

Sorption of cesium on illite: Non-equilibrium behaviour and reversibility

https://digitalcommons.unl.edu/cgi/viewcontent.cgi?article=1250&context=usdoepub

Sorption of Cs+ to micaceous subsurface sediments from the Hanford site, USA

The fallout of radiocaesium after the Chernobyl accident has renewed interest in its environmental behaviour. How it behaves in soils and sediments is important, for example, for the modelling of radiocaesium transport and retention in soils, and transfer from soil to plants and hence into the food chain. The traditional approach is highly empirical and is based on the measurement of solid–liquid distribution coefficients (KD values) and transfer factors. It is generally believed that radiocaesium retention in soils and sediments is due to the presence of a small number of highly selective sites. Neither their abundance nor their Cs-selectivity has been quantitatively determined. Here we report a new methodology which achieves such characterization. Previously studies of radio-caesium in soils have foundered because KD values have been derived under conditions very different from those in situ. We show that in situ KD values can be predicted from readily measurable soil properties, thus enabling information about the mobility of radiocaesium in soils to be reliably and easily obtained. These findings can be generally applied to a wide variety of soils.

A. Maes

Papers

Quantitative analysis of radiocaesium retention in soils