Radionuclide species seawater

It is clear from previous comments that radionuclide speciation studies must consider not only oxidation states and specific inorganic forms but also complex species arising through association with natural organic matter and the possibility of different physical states. The relative importance of these various physicochemical forms will, in practice, be dictated by a combination of the basic elemental characteristics of the radionuclide and the type of environment into which it is placed. Thus in seawater, colloidal organic complex species are likely to be far less dominant than for the same radionuclide in a very low ionic strength freshwater. In the case of soil and sediment interstitial waters or groundwaters,... 

Concentration factors and rate constants determined experimentally in the oyster Crassostrea gigas and the clam Mya arenaria differ widely with species and element. The physical form of the element in the water affects turnover also accumulation of radionuclides of Co, Cs, Mn, and Zn is greater in water containing suspended particles. The chemical form of the element in the water affects its accumulation. When glycine, ethylenediaminetetraacetate (EDTA), yellow stuff , or clay are added to seawater, the accumulation of Cu and Zn by the oyster differs with each test material glycine increases and EDTA decreases the accumulation of both elements. 

Of special interest is the concentration of radioactivity in seawater by the living species. This is shown in Table 2.5. The concentration factors for some radionuclides in some species can be as high as hundreds of thousands. 

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