Objectif Hydrogen cyanide (HCN) is a toxic compound, whose sources in natural aquatic systems are mostly of anthropogenic origin. Although a variety of organisms, most notoriously vascular plants, produces HCN, its release from natural sources is not considered to be an important source of HCN contamination of aquatic environments. Recent results of my research showed that concentrations of HCN, which are toxic to aquatic species, are released in the anoxic ferruginous and sulfidic sediments of the Delaware Great Marsh (DGM) from the roots of cord grass Spartina alterniflora. The main sinks for HCN in the DGM sediments are the formation of metallo-cyanide complexes and reaction with reactive zero-valent sulfur species, which lead to the formation of thiocyanate.I propose to conduct a study to clarify a) the prevalence of HCN release in various aquatic systems; b) which biogeochemical processes control the release and scavenging of HCN in natural aquatic systems; and c) the kinetics of chemical reactions underlying reactions of HCN in natural aquatic systems.In the first stage of the research representative examples of various types of oxygen-depleted aquatic systems (meromictic lakes, marine water bodies with restricted circulation, ocean upwelling zones and sedimentary pore-waters) will be assayed for the presence of relatively stable products of HCN transformations, i.e. thiocyanate and strong metallo-cyanide complexes. The next stage will include a detailed study of biogeochemical mechanisms of cyanide release and transformations in three selected systems. These studies will be accompanied by laboratory experiments to determine the rates of reactions between metallo-complexed and adsorbed cyanide with zero-valent sulfur species abundant in natural aquatic systems (e.g. solid sulfur, colloidal sulfur, dissolved sulfur, polysulfides, polythionates, thiosulfate and organic polysulfanes). Champ scientifique natural scienceschemical sciencesinorganic chemistryinorganic compoundsnatural sciencesearth and related environmental sciencesgeochemistrybiogeochemistry Programme(s) FP7-PEOPLE - Specific programme "People" implementing the Seventh Framework Programme of the European Community for research, technological development and demonstration activities (2007 to 2013) Thème(s) FP7-PEOPLE-2011-CIG - Marie-Curie Action: "Career Integration Grants" Appel à propositions FP7-PEOPLE-2011-CIG Voir d’autres projets de cet appel Régime de financement MC-CIG - Support for training and career development of researcher (CIG) Coordinateur BEN-GURION UNIVERSITY OF THE NEGEV Contribution de l’UE € 100 000,00 Adresse . 84105 Beer Sheva Israël Voir sur la carte Type d’activité Higher or Secondary Education Establishments Contact administratif Daphna Tripto (Ms.) Liens Contacter l’organisation Opens in new window Site web Opens in new window Coût total Aucune donnée