title: Isotopic Fingerprints of Iron-Cyanide Complexes in the Environment.
abstract: Tracing the origin of iron-cyanide complexes in the environment is important because these compounds are potentially toxic. We determined the stable isotopic compositions of cyanide-carbon (CCN) and cyanide-nitrogen (NCN) in 127 contaminated solids and 11 samples of contaminated groundwater from coal carbonization sites, blast furnace operations, and commercial cyanide applications. Coal-carbonization-related cyanides had unique high mean δ(13)CCN values of -10.5 ± 3.5‰ for the solids and -16.1 ± 1.2‰ for the groundwater samples, while the values for blast furnace sludge (-26.9 ± 1.5‰), commercial cyanides (-26.0 ± 3.0‰), and their corresponding groundwaters were significantly lower. Determination of δ(13)CCN is a promising tool for identifying the source of cyanide contamination. However, for coal carbonization sites, historical research into the manufacturing process is necessary because a nonconventional gas works site exhibited exceptionally low δ(13)CCN values of -22.7 ± 1.7‰. The δ(15)NCN values for samples related to coal carbonization and blast furnaces overlapped within a range of +0.1 to +10.3‰, but very high δ(15)NCN values seemed to be indicative for a cyanide source in the blast furnace. In contrast, commercial cyanides tend to have lower δ(15)NCN values of -5.6 to +1.9‰ in solids and -0.5 to +3.0‰ in the groundwater.
authors.affiliation: Universität zu Köln , Department Geowissenschaften, Bodengeographie/Bodenkunde, D-50923 Köln, Germany.
authors.forename: Tim
authors.initials: T
authors.lastname: Mansfeldt
authors.affiliation: Aix-Marseille Université, Laboratoire Chimie Environnement, UMR 7376-CNRS, Marseille, France.
authors.forename: Patrick
authors.initials: P
authors.lastname: Höhener
mesh_terms: D003031:Coal; D003486:Cyanides; D004777:Environment; D060587:Groundwater; D007501:Iron
chemical_list: D003031:Coal; D003486:Cyanides; D007501:Iron