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Dermatas D.,National Technical University of Athens | Vatseris C.,Intergeo Environmental Technology Ltd | Chrysochoou M.,University of Connecticut
Chemical Engineering Transactions | Year: 2012

This study aims to investigate the potential contribution of geogenic chromium (Cr) to a contaminated aquifer of a heavily industrialized area in Greece. Until recently, high levels of Cr(VI) in the environment have always been attributed to anthropogenic activities, since the wide application of chromium in industry and the neglectful industrial waste disposal has in many cases resulted in serious soil and groundwater contamination incidents. However, a series of publications during the last decade have indicated that chromium might be of natural origin, as well. Therefore, a thorough literature review was performed and a comprehensive monitoring protocol, including a long series of water quality parameters, was adopted. Preliminary results indicate that the Cr(VI) plume in the study area is likely caused by a combination of geogenic and anthropogenic sources. Copyright © 2012, AIDIC Servizi S.r.l. Source


Panagiotakis I.,National Technical University of Athens | Dermatas D.,National Technical University of Athens | Vatseris C.,Intergeo Environmental Technology Ltd | Chrysochoou M.,University of Connecticut | And 3 more authors.
Journal of Hazardous Materials | Year: 2015

A forensic investigation was conducted with the aim of decoupling the contribution of geogenic and anthropogenic Cr(VI) sources in the wider area of Thiva. Groundwater and topsoil samples were collected from two Cr(VI) groundwater plumes of 160. μg/L and 75. μg/L. A series of evidence support the view that the origin of Cr(VI) detected in groundwater is mainly geogenic. These are: (a) the presence of Cr in topsoil of the wider area, (b) the moderate Cr(VI) groundwater concentrations, (c) the high Ni levels within the Cr(VI) plumes, (d) the predominance of Mn(IV), which is a prerequisite for Cr(III) oxidation to Cr(VI), and (e) the absence of co-contaminants. The present study also revealed that, although both Cr(VI) plumes are clearly of geogenic origin, the plume with the elevated Cr(VI) values, in the north of Thiva town, exhibits also an anthropogenic component, which can potentially be attributed to the alkaline environment associated with the old uncontrolled landfill of Thiva and the industrial cluster located in this area. © 2014 Elsevier B.V. Source


Dermatas D.,National Technical University of Athens | Mpouras T.,National Technical University of Athens | Chrysochoou M.,University of Connecticut | Panagiotakis I.,National Technical University of Athens | And 7 more authors.
Journal of Hazardous Materials | Year: 2015

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 7.5. mg/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. © 2014 Elsevier B.V. Source


Mountouris A.,Health | Leventos D.,Health | Papadimos D.,Health | Antotsios C.,Health | And 5 more authors.
Desalination and Water Treatment | Year: 2011

Utilization of waste materials generated in different industries is important from the points of ecology, economics and conservation of non-renewable resources. One of the main waste materials in petroleum industry is oil sludge, which is produced by the treatment of wastewater, from various refining and tank cleaning processes. Biotreatment or otherwise biodegradation by natural populations of microorganisms is one of the primary mechanisms by which petroleum and other hydrocarbon pollutants can be eliminated from the environment. The biotreatment technology by biopiles, which is applied in Thessaloniki Refinery area of Hellenic Petroleum S.A., for the case of the solid residual material (SRM) (dewatered oil sludge) derived from oil refinery sludge, is presented in this study. Experimental results presented herein demonstrate the fact that the biotreatment method of biopiles in the case of solid residual material stemming from oil refinery sludge can achieve high biodegradation efficiencies for organic substances and low leaching levels for heavy metals. Conclusively, Thessaloniki refinery's biotreatment unit is proven to be one effective and environmentally sustainable treatment option for the oil refinery sludge and its solid residual material, saving valuable natural resources, i.e. non impacted natural soil, which can be used mainly in earthworks or as cover material in landfill sites. © 2011 Desalination Publications. All rights reserved. Source

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