UMR CNRS 5805 EPOC
Environnements et Paléoenvironnements
Océaniques et Continentaux

        

Consignes de Sécurité et Numéros d'Urgence
(à l'usage des personnels du laboratoire)

le 03-12-2010 à 10:45

Lieu Salle Stendhal, DGO, Bâtiment B18 Intervenant(s) Anniet LEVERMAN, UMR 7619 Sisyphe, Université Pierre et Marie Curie, Paris 6

Nitrate reduction plays a key role in organic carbon mineralization and nitrogen removal in aquatic sediments. In this seminar I will present potential nitrate reduction rates obtained on intact sediments by using plug flow-through reactors. As the driving forces of heterotrophic nitrate reduction are nitrate and carbon, the effects of these two factors on nitrate reduction rates as well as on the production of (intermediate) nitrous oxide will be shown. By using the acetylene block technique and as well as using stochiometric calculations based on ammonium production versus nitrate reduction I have attempted to determine the importance of denitrification, dissimilatiry nitrate reduction to ammonium and anammox in a wide range of sediments. Alternative nitrate reduction, using inorganic electron donors such as Fe(II) and H2S, will also be discussed. Finally I will show some examples of the implementation of the obtained experimental data in diagenetic modeling.