Soil contamination by heavy metals: Measurements from a closed unlined landfill

The aim of the present study was the characterization of soil samples of a closed unlined landfill located northwest of Thessaloniki, North Greece, in relation to heavy metals values. Samples were obtained by drilling in different depths (2.5–17.5 m). Then they were analyzed by atomic absorption spectrophotometry for Cd, Cr, Cu, Ni, Pb and Zn investigation. The chemical analysis showed that the metal values varied over a wide range: from 0.50 to 18.75 mg/kg for Cd, 3.88–171.88 mg/kg for Cr, 8.13–356.25 mg/kg for Cu, 5.63–63.75 mg/kg for Ni, 2.50–92.50 mg/kg for Pb and 6.38–343.75 mg/kg for Zn. The highest values found in three of the six drillings, in depths over 2.5 m. Although the area is heavily industrialized, the presented results indicated that local industries have not constituted an extensive metal pollution source for the site. Finally, after all necessary preparatory operations of site cleaning and flattening, surface planting selected and applied as a phytoremediation rehabilitation method of the site.