Couplage des équations de transfert de masse et des lois d'interactions solution-solide par l'utilisation des lanthanides comme traceurs — Approche expérimentale

Abstract In underground flow tracing studies, the estimation of the nature and the importance of interactions undergone by the substance used very often constitutes an obstacle to good modeling of mass-transfer processes in solution. We propose a method to quantify these phenomena by the use of lanthanides as tracers. For this study, we set up an analytical methodology adapted to routine measurements. The quality of five lanthanides as indicators has been examined. We have demonstrated the formation, by substitution, of a carbonate complex which is extremely stable in the natural environment. The field experiments carried out demonstrated the efficiency of those tracers and confirmed their great stability. Tracer recovery graphs show that, in accord with our hypothesis, convection and dispersion are identical for all the lanthanide elements. Moreover, we have established a direct relation between their fixing rate on earth materials and the value of their stability constants. Thus, we demonstrate the possibility of correlative multitracing, with known and quantifiable interelement relations.