A preliminary study to assess the effect of some seawater components on the speciation of plutonium

Since Pu(IV) and Pu(V) exhibit very different sediment sorption behaviour, the transport of Pu in the aquatic environment is dependant upon oxidation state and the rate of interconversion between the species. A number of laboratory experiments have been carried out to determine possible parameters which influence the rate of Pu redox reactions and the extent of sorption by suspended particulate in the marine environment. Results suggest that, although the initial sorption of Pu(IV) did not appear to be dependant upon the major cations present in seawater, the sorption of Pu(V) was decreased in the presence of Ca²⁺ and Mg²⁺ ions. Both the rates of oxidation of dissolved Pu(IV) and reduction of dissolved Pu(V) increased with increasing suspended particulate concentration.