title: Metal(loid) speciation and size fractionation in sediment pore water depth profiles examined with a new meso profiling system.
abstract: In an exemplary incubation study with an anaerobic sediment sampled at an oxbow of the river Lahn in Germany (50°18'56.87″N; 7°37'41.25″E) and contaminated by former mining activity, a novel meso profiling and sampling system (messy) is presented. Messy enables a low invasive, automated sampling of pore water profiles across the sediment water interface (SWI), down to ∼20 cm depth with a spacial resolution of 1 cm. In parallel to the pore water sampling it measures physicochemical sediment parameters such as redox potential and pH value. In an incubation experiment of 151 days the ability of the setup was proven to address several different aspects relevant for fresh water and marine sediment studies: (i) The influence of mechanical disturbance and oxygen induced acidification on the mobility of 13 metals and metalloids (Cd, Co, Cu, Fe, Mn, Mo, Ni, Sb, U, V, Zn) was quantified based on 11 profiles. The analytes were quantified by inductively coupled plasma-mass spectrometry. Three groups of elements were identified with respect to the release into the pore water and the overlying water under different experimental conditions. (ii) The capability to investigate the impacts of changing physicochemical sediment properties on arsenic and antimony (III/V) speciation is shown. (iii) An approach to obtain information on size fractionation effects and to address the colloidal pore water fractions (0.45 μm-16 μm) was successfully conducted for the elements Ag, As, Cu, Fe and Mn.
authors.affiliation: Federal Institute of Hydrology, Division G - Qualitative Hydrology, Am Mainzer Tor 1, 56068 Koblenz, Germany.
authors.forename: Henning
authors.initials: H
authors.lastname: Schroeder
authors.affiliation: Federal Institute of Hydrology, Division G - Qualitative Hydrology, Am Mainzer Tor 1, 56068 Koblenz, Germany.
authors.forename: Anne-Lena
authors.initials: AL
authors.lastname: Fabricius
authors.affiliation: Federal Institute of Hydrology, Division G - Qualitative Hydrology, Am Mainzer Tor 1, 56068 Koblenz, Germany.
authors.forename: Dennis
authors.initials: D
authors.lastname: Ecker
authors.affiliation: Federal Institute of Hydrology, Division G - Qualitative Hydrology, Am Mainzer Tor 1, 56068 Koblenz, Germany.
authors.forename: Thomas A
authors.initials: TA
authors.lastname: Ternes
authors.affiliation: Federal Institute of Hydrology, Division G - Qualitative Hydrology, Am Mainzer Tor 1, 56068 Koblenz, Germany. Electronic address: duester@bafg.de.
authors.forename: Lars
authors.initials: L
authors.lastname: Duester
mesh_terms: D004784:Environmental Monitoring / Q000379:methods*; D005618:Fresh Water / Q000032:analysis / Q000737:chemistry; D019015:Geologic Sediments; D005858:Germany; D058955:Metalloids / Q000032:analysis*; D008670:Metals / Q000032:analysis* / Q000737:chemistry; D019216:Metals, Heavy / Q000032:analysis; D008906:Mining; D016062:Porosity; D045483:Rivers / Q000737:chemistry*; D014874:Water Pollutants, Chemical / Q000032:analysis*
chemical_list: D058955:Metalloids; D008670:Metals; D019216:Metals, Heavy; D014874:Water Pollutants, Chemical
keywords: Depth profile; Metals; Profiling; Sediment pore water; Sediment water interface