PARENT SESSION
PTA15 - Bioavailability
8:00 AM to 6:30 PM - Tuesday, November 13, 2001
Exhibit Hall A

(PT236) The Influence of Solution Speciation on Uranium Uptake by a Freshwater Bivalve.

Denison, Frank¹, Adam, Christelle¹, Garnier-Laplace, Jaqueline¹, ¹

ABSTRACT- The bioavailability of uranium to a number of different species has been shown to be strongly influenced by the physicochemical conditions of the exposure medium. In the context of the development of a uranium transfer model for freshwater bivalves, a series of experiments have been performed to identify the most important uranium solution species responsible for uranium uptake by a model bivalve species (Corbicula fluminea). The exposure experiments were performed in regulated and well characterised synthetic solutions, the compositions of which were varied in a systematic manner to investigate the influence of the main physicochemical parameters. The uptake kinetics of uranium was measured over relatively short time periods at both a whole body and individual tissue level. The uptake was interpreted in terms of the modelled solution speciation of uranium. This approach enables the development of a mechanistic model, avoiding some of the problems inherent in the more commonly applied approach of using empirical relationships between bioavailability and physicochemical parameters.

Key words: uranium, bioavailability, speciation, bivalve