Fate of aluminium released by sacrificial anodes – Contamination of marine sediments by environmentally available compounds

International audienc

Prediction of phytoavailability of trace metals to plants: Comparison between chemical extractions and soil-grown radish

International audienc

Sustanaible re-use of marine dredged sediments: roads and bricks as two examples

International audienc

Selectivity and efficiency of the acido-soluble extraction in sequential extraction procedure

International audienc

Évaluation de la mobilité des métaux dans les sédiments fluviaux du bassin de la Vire (Normandie, France) par extractions simples ou séquentielles

International audienceReçu le 1 er mars 2004 ; accepté après révision le 21 décembre 2004 Disponible sur Internet le 8 mars 2005 Présenté par Georges Pédro Résumé Ce travail compare la quantité de métaux présents dans des sédiments fluviaux de la Vire (Normandie), mobilisés par dif-férentes extractions chimiques, simples (Mg(NO 3) 2 , HCl et EDTA) ou séquentielle. Le lessivage par Mg(NO 3) 2 sous-évalue la mobilité, tandis que l'extraction séquentielle est la plus agressive des méthodes utilisées (sauf pour le calcium et le plomb), sans qu'il soit possible de déterminer de façon satisfaisante et univoque à quelle(s) fraction(s) du sédiment correspondent les quantités mobilisées par les lessivages simples, de grandes variabilités apparaissant suivant l'élément considéré. Enfin, on note un enrichissement en polluants métalliques (Cd, Pb et Zn) des sédiments étudiés. Pour citer cet article : L. Leleyter, F. Baraud, C. R. Geoscience 337 (2005). 2005 Académie des sciences. Publié par Elsevier SAS. Tous droits réservés. Abstract Evaluation of metals mobility in sediments of the Vire basin (Normandy, France) by single or sequential extractions. This work compares the quantities of labile metals removed from the Vire River (Normandy) sediments by a sequential extraction procedure to those liberated by single leaches (Mg(NO 3) 2 , HCl and EDTA). Compared to the other extractions, Mg(NO 3) 2 underestimated the mobility results. The sequential procedure was the most aggressive, except for Ca and Pb. The hypothetic correlation between quantities of an element removed by single leaches and its fractionation in the sediment according to the sequential procedure was not satisfying. Finally, it should be underlined that enrichments of Cd, Pb and Zn were noticed in the Vire sediments. To cite this article: L. Leleyter, F. Baraud, C. R. Geoscience 337 (2005). 2005 Académie des sciences. Publié par Elsevier SAS. Tous droits réservés

Electrokinetic remediation of dredged sediments from Le Havre Harbour

International audienc

Sustanaible re-use of marine dredged sediments: roads and bricks as two examples

International audienc

Ion velocity in soil solution during electrokinetic remediation

International audienceDuring the electrodecontamination of soils the pollutants' fluxes control the decontamination time. Application of this technique to real cases necessitates some simple predictive tools to rapidly evaluate the feasibility of the method. The pollutants' fluxes depend on their concentration and their velocity in the soil solution. In this paper our interest focuses on this pore velocity. A simple expression for the velocity of cationic species in the pore solution is proposed, for a wide range of situations where electroosmosis and electromigration are the major contributing ion transport mechanisms (governed by the electrical field applied). An adapted methodology is developed (pH control, steady-state conditions) and applied at laboratory scale using kaolinite as a soil model and some cations as model pollutants. Experimental results and theoretical calculations are compared. 0 1997 Elsevier Science B.V

Temperature effect on ionic transport during soil electrokinetic treatment at constant pH

International audienceLaboratory experiments and theoretical modelling generally proposed for electrokinetic soil processing consider isothermal conditions at room temperature. Important increases of the soil temperature, due to the Joule effect, have been observed during pilot or field-scale tests. The temperature effect on the transport of ionic species present in the pore solution is investigated when an electric field is applied through the soil mass. Laboratory experiments are run at 20 and 408C using kaolinite as soil model and one anion and one cation as model pollutants. An adapted Ž. methodology pH control, steady state conditions allows the measurement and the comparison of the ionic electrokinetic velocities at the two temperatures. Under the conditions developed, the temperature mainly influences the ionic velocities, which increase, for the two ions of interest, when the temperature rises