Mobility of the dissolved organic matter through intact boom clay cores

Performance assessment studies are expected to predict the enhancement of t he migration of trivalent lanthanides and actinides due to their complexati on with organic matter, which play a role as a transport agent [1]. Therefo re, the mobility of the dissolved organic matter in the interstitial Boom C lay water is studied. For the first time, the mobile fraction present in th e clay water is concentrated and labelled with a radioisotope to study the mobility of the organic matter in clay and the interaction of the mobile wi th the non-mobile. The isotopes tested as label are I-125 and C-14. The I-1 25 label proved to be unstable and hence discarded. The labelled organic ma tter is then diluted for migration experiments on Boom Clay cores under ana erobic conditions. The influence of the molecular size on its mobility is s tudied by the separation of the labelled organic matter in different size f ractions.