title: Origin and concentration profile of chromium in a Greek aquifer.
abstract: In this paper the origin and concentration of chromium (Cr) in an ophiolitic aquifer in Vergina, northern Greece were investigated. The study area has only agricultural activity so that industrial Cr contamination was precluded. Soil sampling included topsoil and drillcore samples collected down to 98 m depth. Groundwater samples were collected from three existing wells and a spring at the area and from different depths of the soil boring using the discrete sampling method. Mineralogical analysis of soils confirmed the presence of ultramafic minerals, including chrysotile and chromite. Soil elemental analysis showed significant concentration of total chromium (Crtot; max 12,000 mg/kg) and hexavalent chromium (Cr(VI); max 7.5mg/kg). Significant Crtot (91 μg/L) and Cr(VI) (64 μg/L) concentrations exceeding the drinking water limit of 50 μg/L were also detected in groundwater. In both the discrete soil and groundwater samples a decreasing trend of Cr(VI) concentration was observed with increasing depth, while Crtot increased. The increasing trend in Crtot is attributed to the increasing contribution of unweathered ultramafic minerals with depth, while the decreasing Cr(VI) may be related to the increasing soil pH that does not favor Cr(III) oxidation by Mn-oxides.
authors.affiliation: School of Civil Engineering, Department of Water Resources and Environmental Engineering, National Technical University of Athens, Iroon Polytechniou 9, 157 80 Zografou, Greece.
authors.forename: Dimitris
authors.initials: D
authors.lastname: Dermatas
authors.affiliation: School of Civil Engineering, Department of Water Resources and Environmental Engineering, National Technical University of Athens, Iroon Polytechniou 9, 157 80 Zografou, Greece. Electronic address: th.mpouras@gmail.com.
authors.forename: Thanasis
authors.initials: T
authors.lastname: Mpouras
authors.affiliation: Department of Civil and Environmental Engineering, University of Connecticut, Storrs, CT, USA.
authors.forename: Maria
authors.initials: M
authors.lastname: Chrysochoou
authors.affiliation: School of Civil Engineering, Department of Water Resources and Environmental Engineering, National Technical University of Athens, Iroon Polytechniou 9, 157 80 Zografou, Greece.
authors.forename: Iraklis
authors.initials: I
authors.lastname: Panagiotakis
authors.affiliation: Intergeo - Environmental Technology Ltd, Industrial Area of Thermi, Thessaloniki 57 001, Greece.
authors.forename: Christos
authors.initials: C
authors.lastname: Vatseris
authors.affiliation: Intergeo - Environmental Technology Ltd, Industrial Area of Thermi, Thessaloniki 57 001, Greece.
authors.forename: Nikos
authors.initials: N
authors.lastname: Linardos
authors.affiliation: School of Civil Engineering, Department of Water Resources and Environmental Engineering, National Technical University of Athens, Iroon Polytechniou 9, 157 80 Zografou, Greece.
authors.forename: Eleni
authors.initials: E
authors.lastname: Theologou
authors.affiliation: School of Civil Engineering, Department of Water Resources and Environmental Engineering, National Technical University of Athens, Iroon Polytechniou 9, 157 80 Zografou, Greece.
authors.forename: Nefeli
authors.initials: N
authors.lastname: Boboti
authors.affiliation: School of Mining and Metallurgical Engineering, National Technical University of Athens, Iroon Polytechniou 9, 157 80 Zografou, Greece.
authors.forename: Anthimos
authors.initials: A
authors.lastname: Xenidis
authors.affiliation: School of Mining and Metallurgical Engineering, National Technical University of Athens, Iroon Polytechniou 9, 157 80 Zografou, Greece.
authors.forename: Nymphodora
authors.initials: N
authors.lastname: Papassiopi
authors.affiliation: School of Mining and Metallurgical Engineering, National Technical University of Athens, Iroon Polytechniou 9, 157 80 Zografou, Greece.
authors.forename: Lefki
authors.initials: L
authors.lastname: Sakellariou
mesh_terms: D004784:Environmental Monitoring; D006115:Greece; D060587:Groundwater / Q000032:analysis*; D008670:Metals / Q000032:analysis*; D008903:Minerals / Q000032:analysis; D012989:Soil Pollutants / Q000032:analysis*; D014874:Water Pollutants, Chemical / Q000032:analysis*
chemical_list: D008670:Metals; D008903:Minerals; D012989:Soil Pollutants; D014874:Water Pollutants, Chemical
keywords: Discrete sampling; Geogenic; Groundwater; Hexavalent chromium; Ultramafic soils