Cesium iron effects

The CHEMIC process is effective in removing cadminm, mercnry, lead, iron uranium, strontium, cesium, and cobalt. The process also removes other inorganic and organic materials present as suspended or colloidal solids. 

The construction and application work on the linear model of sorption has important results. First, the distribution coefficients of the different minerals for radioactive ions in very low concentrations can be determined. The minerals with similar structure obviously have similar distribution coefficients because of the similar sorption mechanism. The differences are the results of a specific property of the minerals for example, the presence of iron of magnesium in carbonates has a significant effect on the sorption of the cesium ion. 

Hutchings (170) plotted (Figure 31) the activity against the surface area for a number of promoted catalysts and deduced that most of the catalysts conform to a linear correlation. The only enhancement of the specific activity was observed for the cerium-promoted catalyst. This result shows that care must be taken in the interpretation of the catalyst performance data, particularly when catalysts prepared by different methods are compared. In a separate study, Hutchings and Higgins (171) found that chromium, niobium, palladium, antimony, ruthenium, thorium, zinc, and zirconium each had very little effect on the specific activity of (VO)2P207. A significant increase in surface area was observed with zirconium, zinc, and chromium, which could be of use as structural promoters. Iron-, cesium-, and silver-doped catalysts decreased the specific activity, and cobalt and molybdenum were the only promoters found to increase the specific activity. 

Typical effects of the separation methods on the partition coefficient have been studies by Calmano (1979). Data from radionuclide analysis in Table 4-2 indicate that distribution coefficients between solid and aqueous phases generally are higher from filtration methods than from centrifuge separation for cesium and chromium the difference is a factor of about 10, for iron even higher. 

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