Plutonium sorption variables

All plutonium solutions, except where pH was a variable, were buffered at pH 7 with phosphate. The final concentration of the phosphate, as KH2P04, was typically 0.001M. Experiments on the effect of phosphate on plutonium sorption indicated that there should be no increase in sorption resulting from formation of a plutonium-phosphate complex at this concentration. All experiments, except where temperature was a variable, were carried out at room temperature, which was usually between 24° and 26 °C. 

Fig. 2. Isotherm data for radium, uranium(VI) and plutonium sorption onto haematite (using the batch-sorption technique, liquid solid ratio indicated on diagrams). The general form of the data is consistent with a linear sorption mechanism. For information, error bars corresponding to 40% of the measured value are shovra (see text for further discussion of experimental variability).

Variables found to be significant for sorption of cesium, strontium, technetium, selenium, neptunium, plutonium, americium, and radium on sandstone and tuff at 23°C are given in Table VII. They are ranked in order of significance where more than one variable was found to be significant. The ( + ) and (-) signs indicate whether sorption is increased or decreased. 

There have been several laboratory and field studies concerned with the uptake of aqueous plutonium by plants, marine biota, soils, minerals, and glass. These have been discussed in the first paper of this series (I), which shows that several solution variables, as they influence the particle size distribution of the aqueous plutonium, greatly affect its interaction with silica surfaces. Studies were conducted to determine the rates, equilibria, and mechanism of the sorption and desorption of aqueous, colloidal plutonium-239 onto the surfaces of quartz silica. The orientation of these studies is the understanding of the likely behavior and fate of plutonium in environmental waters, particularly as related to its interaction with suspended and bottom sediments. 

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