GNGTS 2024 - Atti del 42° Convegno Nazionale

Session 3.2 GNGTS 2024 A Dynamic and Mult-Source Hydrogeophysical Model to Remediate a Complex Hydrocarbon- Contaminated Site P.Ciampi 1 , G.Cassiani 2 , G.P.Deidda 3 , C.Esposito 1 , G.Scarascia Mugnozza 1 , M. Petrangeli Papini 4 1 Department of Earth Science, Sapienza University of Rome 2 Department of Geosciences, University of Padua 3 Department of Civil, Environmental Engineering and Architecture, University of Cagliari 4 Department of Chemistry, Sapienza University of Rome Contaminated sites pose intricate challenges in characterizaton and remediaton planning due to the complex interplay of contaminants and hydrogeological propertes, ofen resultng in under- sampling issues at the site-specifc scale. This study introduces a dynamic mult-source approach to address the challenges of characterizing and remediatng a hydrocarbon-contaminated site. A comprehensive dataset is compiled from diverse sources, including stratgraphic boreholes, laser- induced fuorescence surveys (LIF), electrical resistvity tomography (ERT), and groundwater hydrochemical monitoring. These data are integrated into an interactve big-data package, enabling real-tme 3D modeling throughout the characterizaton and remediaton phases. The study yields a comprehensive conceptual hydrogeophysical model that captures hydrogeological and geophysical structures, as well as the spatal and temporal dynamics of contaminaton. By combining knowledge from multple sources, the mult-source hydrogeophysical clone provides qualitatve- quanttatve indicators to reduce uncertaintes associated with subsurface interpretaton by separatng signatures of geologic material in the absence of light non-aqueous phase liquids (LNAPL) and the local increase in electrical conductvity associated with petroleum hydrocarbon biodegradaton. It reveals the real characteristcs of the pollutant, contaminaton mechanisms, and residual hydrocarbon sequestraton infuenced by hydrogeological dynamics and on-site remediaton actons. The emerging hydrogeophysical conceptual site model (CSM) serves as a dynamic interface for designing enhanced remediaton actons, specifcally targetng LNAPL and involving reagent injectons into the subsurface to stmulate the desorpton and oxidaton of residual hydrocarbons. Geophysical monitoring, utlizing ERT, reveals subsurface dynamics and variatons in electrical conductvity during injecton, extracton, and subsequent pumping actvites. The study underscores the importance of collectng diverse data for a reliable and high-resoluton reconstructon of the conceptual framework. The dynamic mult-source model explains contaminaton/decontaminaton dynamics based on the variaton of electrical propertes in space- tme, also induced by the applicaton of remediaton processes at the feld scale. Data-driven model discriminates geophysical evidence on the basis of lithologic characteristcs and