Summary of studies on (ad)sorption as a “well-established” process within FUNMIG activities

This paper summarizes the activities within the European project FUNMIG (FUNdamental Processes of Radionuclide MIGration) concerned with sorption as a “well-established” process. Within FUNMIG, many, if not all, work-packages in some way involved sorption processes. In order to avoid repetition within this special issue and to have a clear separation, the present contribution only gives an impression of the work done within the one particular work-package with the above title. The various subprojects from that work-package were regrouped into studies on model sorbents, on sorbents directly pertaining to host rock formations and on studies primarily concerned with sorption. For each of the issues a short summary with an aspect that may be of particular interest to readers from outside the nuclear waste community is given. The work on sorption covers experimental and modeling work on model sorbents (silica and alumina), sorbents related to the engineered barrier (clay minerals) and identified host rock formation related sorbents (clay minerals in France, Switzerland and Belgium; granite in Sweden and Finland). Experimental and modeling results on these systems are addressed in some detail. Pure modeling studies on database building and evaluation of highly simplified adsorption models were also carried out and these will be discussed along with a suggestion to relate a model to a certain purpose to facilitate justification of the model approach chosen.