X-ray Absorption Fine Structure Evidence for Amorphous Zinc Sulfide as a Major Zinc Species in Suspended Matter from the Seine River Downstream of Paris, Ile-de-France, France

Abstract

Zinc is one of the most widespread trace metals (TMs) in Earth surface environments and is the most concentrated TM in the downstream section of the Seine River (France) due to significant anthropogenic input from the Paris conurbation. In order to better identify the sources and cycling processes of Zn in this River basin, we investigated seasonal and spatial variations of Zn speciation in suspended particulate matter (SPM) in the oxic water column of the Seine River from upstream to downstream of Paris using synchrotron-based extend X-ray absorption fine structure (EXAFS) spectroscopy at the Zn K-edge. First-neighbor contributions to the EXAFS were analyzed in SPM samples, dried and stored under a dry nitrogen atmosphere or under an ambient oxygenated atmosphere. We found a sulfur first coordination environment around Zn (in the form of amorphous zinc sulfide) in the raw SPM samples stored under dry nitrogen vs an oxygen first coordination environment around Zn in the samples stored in an oxygenated atmosphere. These findings are supported by scanning electron microscopy and energy dispersive X-ray spectrometry observations. Linear combination fitting of the EXAFS data for SPM samples, using a large set of EXAFS spectra of Zn model compounds, indicates dramatic changes in the Zn speciation from upstream to downstream of Paris, with amorphous ZnS particles becoming dominant dowstream. In contrast, Zn species associated with calcite (either adsorbed or incorporated in the structure) are dominant upstream. Other Zn species representing about half of the Zn pool in the SPM consist of Zn-sorbed on iron oxyhydroxides (ferrihydrite and goethite) and, to a lesser extent, Zn-Al layered double hydroxides, Zn incorporated in dioctahedral layers of clay minerals and Zn sorbed to amorphous silica. Our results highlight the importance of preserving the oxidation state in TM speciation studies when sampling suspended matter, even in an oxic water column.

Trace element behavior and partition versus urbanization gradient in an urban river (Orge River, France)

“…A1). Copper, Zn, and Pb concentrations in the Orge River catchment were comparable with those reported in the case of highly polluted rivers, like in smelting impacted ones (Audry et al, 2006;Heliosrybicka et al, 2005) and, from our knowledge, zinc concentrations in the Orge River SPM are the highest reported values for the Seine River catchment (ElbazPoulichet et al, 2006;Meybeck et al, 2004Meybeck et al, , 2007Priadi et al, 2011Priadi et al, , 2012.…”

“…Nature of SPM also influences TE partition through the difference of reactivity between the mineralogical phases. Within the particulate phase, in such environments, TE are usually associated with iron or manganese oxy(hydro)oxides (Toner et al, 2006), clay components (Jacquat et al, 2009), calcite, or in sulfide minerals (Priadi et al, 2012).…”

Integrated Approaches of X‐Ray Absorption Spectroscopic and Electron Microscopic Techniques on Zinc Speciation and Characterization in a Final Sewage Sludge Product

“…Post treatments of fresh sewage sludge materials to meet the quality for land application, stockpiling, and/or composting are expected to have a significant influence on Zn speciation in sewage sludge products (i.e., Zn association with iron oxide phases) (Donner et al, 2012; Lombi et al, 2012). However, there are also field‐scale studies showing the presence of ZnS NPs in oxic water conditions, indicating their persistence and dominance (of the total load) in such an environment (Priadi et al, 2012). Dissolution of bulk ZnS is known to take several years in moist, aerated soils, suggesting that the sulfide phase is relatively insensitive to the oxidation process (Hilber et al, 2007; Hita and Torrent, 2005, 2006; Voegelin et al, 2011).…”

Anthropophile elements in river sediments: Overview from the Seine River, France

“…To summarize, our results clearly illustrate the importance of grain size effects on the chemistry of the Seine River sediments. In particular, RBD (and thus also bed loads) are clearly different from SPM from a geochemical point of view and therefore cannot be used as surrogates of suspended sediments to assess weathering conditions and contamination in a river system [Albarede and Semhi, 1995;Horowitz et al, 1999;Grosbois et al, 2006;Thevenot et al, 2007aThevenot et al, , 2007bFranke et al, 2009;Priadi et al, 2011Priadi et al, , 2012.…”

“…The sediments delivered to the Seine in PTWW are substantially enriched in Zn and Cubearing sulfide minerals, representing up to 40% of heavy metal carriers [Houhou et al, 2009], and organic matter (POC concentrations between 19.5% and 26.3%, supporting information Table S1) formed under anaerobic conditions in the sewer system [Herbert et al, 1998;Jong and Parry, 2003;Seidl et al, 1998b]. The anthropogenic contribution to these two components in the Seine River is apparent from the dramatic increase in amorphous ZnS particles and POC contents from upstream to downstream of Paris city [Meybeck et al, 1998;Seidl et al, 1998a;Priadi et al, 2012]. Cu is an essential bio-element assimilated by organisms and has also a strong affinity for sulfides.…”