Speciation of trivalent f elements in natural waters

Abstract

Using reported stability constants and reasonable concentrations, the speciation of neodymium(III) and americium(III) in marine and fresh waters has been calculated. In seawater, bicarbonate and/or carbonate complexing was dominant with significant organic ligand complexing only at relatively high dissolved organic carbon (DOC) concentrations. The solubility of the carbonate seems to be the limiting factor in the solution concentrations. In fresh waters the complexing by the humic and fulvic material is more important and is dominant at low calcium concentrations.