J. Phys. IV France 107 (2003) 1057
DOI: 10.1051/jp4:20030481

Migration of cadmium through a natural porous medium : Influence of the solid-liquid interface processes

M. Petrangeli Papini¹, A. Bianchi¹, P. Behra², M. Majone¹ and M. Beccari<sup>1

1</sup>  Università degli Studi di Roma La Sapienza, Dipartimento di Chimica, P. le Aldo Moro 5, 00185 Roma, Italy
²  École Nationale Supérieure des Ingénieurs en Arts Chimiques et Technologiques, Laboratoire de Chimie Agro-Industrielle, UMR 1010, INRA/INP-ENSIACET, 118 route de Narbonne, 31077 Toulouse cedex 4, France

Abstract
Contaminated groundwater typically contains different metal contaminants which may compete with each other for the same adsorption sites. Understanding the fate of these micro-pollutants is of primary importance for the assessment of the risk associated to their dispersion in the environment and for the evaluation of the most appropriate remediation technology. By this regard, column techniques can be considered as a useful tool both to perform transport experiments and to obtain equilibrium adsorption data without any perturbation of the solid-liquid interface. Cd and Pb mono-component step column experiments were performed to obtain adsorption isotherms with a natural aquifer material. General Composite approach was used to define the equilibrium adsorption model characterised by two types of sites (ion-exchange and surface complexation sites). Coupling the adsorption model to the Advection-Dispersion equation (by IMPACT code) allowed to well represent the mono-component step experiments. The model was successfully used to predict the competitive Cd and Pb transport behaviour.

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