An integrated approach to characterize a polluted site by combining chemical and geophysical methodologies: a case study in Apulia region.

In recent years, the identification and monitoring of polluted sites have become very important due to the widespread of contamination phenomena. The environmental assessment of contaminated sites is complex and difficult for the variety of the pollutants and for the physical and chemical heterogeneity of polluted sites. Some studies promote an integrated approach, which combines geophysical investigation with geochemical analysis carried out on subsoil samples to quantitatively estimate the extent and the level of the contamination. In this work, a contaminated site located close to Taranto city, in the south of Apulia Region (Italy), has been investigated by chemical and geophysical surveys in order to characterize and evaluate the pollution which is occurring since years. Soil chemical analyses of texture, electrical conductivity, pH, organic carbon content, nitrogen, available phosphorous and carbonate content have been carried out to characterize soil properties of this site. Analytical investigations of pollutants have been performed using Gas Chromatography/Mass Spectrometry (GC/MS) and Inductively Coupled Plasma Mass Spectrometry (ICP-MS) to identify organic or inorganic compounds, respectively. Geophysical survey has been carried out to assess the geological features of the test site and support the results of the physical and chemical soil analysis. Particularly, an Electrical Resistivity Tomography (ERT) profile has been performed to visualize geo-lithological layers and hydrogeological properties for evaluating the vulnerability of the area. Moreover six high resolution ERT and Induced Polarization (IP) profiles have been conducted close to the soil sampling points to image electrical structures in the upper part of the soil, severely contaminated by inorganic and organic pollutants. Preliminary results highlight that this integrated approach can efficiently support soil contamination assessment.