Mobility of organic complexes of nickel and cobalt in soils

The effect of organic complexing agents on the behavior of low-level waste radionuclides in soil/groundwater systems is discussed. Sorption of some complexed radionuclides, as well as of uncomplexed ones, is important with some soils. Sorption of Ni-EDTA and Co-EDTA complexes occurs with soils from Oak Ridge and Savannah River. The sorption of these kinetically inert complexes results in a lower radionuclide migration rate than if it did not occur; however, the migration rate is still greater than if the complexes were not kinetically inert, or if complexants were absent. The comparison of complexing agents was also extended in FY 1983 to include additional individual agents and also some proprietary decontamination mixtures. The results of tests continue to indicate that all organic complexing agents should not be considered to be equally hazardous from a waste disposal standpoint. Different soils affect organic complexant-enhanced radionuclide mobility differently. Some sorb kineticaly inert complexes and some do not. Radionuclide complexes dissociate more rapidly in some soil/groundwater systems than they do in others. Soils also differ in their leaching by complexant solutions, which also affects radionuclide behavior.