Thesis Defense
Student: Marina Fernandes Sanches Barros
Program: Geophysics
Title: “Integrated Application of Geoelectrical Methods for Enhancing the Conceptual Model of Contaminated Areas”
Advisor: Prof. Dr. Vagner Roberto Elis
Judging Committee:
- Prof. Dr. Vagner Roberto Elis - IAG
- Prof. Dr. Jorge Luis Porsani - IAG
- Prof. Dr. Cesar Augusto Moreira - UNESP Rio Claro (on videoconference)
- Prof. Dr. Alice Marques Pereira Lau – UFBA (on videoconference)
- Prof. Dr. Sergio Junior da Silva Fachin – UFMT (on videoconference)
Abstract:
Subsurface contamination, resulting from domestic and industrial waste as well as hydrocarbon spills, is a critical issue that demands continuous monitoring and remediation strategies to preserve groundwater reservoirs. Invasive methods, such as drilling, provide precision but are costly and limited to specific points. In contrast, non-invasive geophysical techniques, such as resistivity and induced polarization (IP), stand out for their wide coverage and rapid data acquisition. The integration of these methods is essential for constructing Conceptual Site Models, which consolidate crucial information to support environmental management decisions. This study investigates the effectiveness of geoelectrical methods in heterogeneous and urbanized environments, evaluating the evolution of contamination plumes and exploring their applicability in different contexts. Three areas were analyzed, each with distinct characteristics and challenges. The first area, located in an urban region of São Paulo, exhibits contamination by tetrachloroethylene (PCE) and is undergoing remediation processes such as chemical oxidation, which alter the site's geoelectrical signature. The capacitive resistive method proved particularly effective in this area due to its ability to operate on paved surfaces without the need for electrode penetration. In the second area, situated in a sanitary landfill in Bauru, the capacitive resistive method was used efficiently, allowing chemical analyses to be conducted at longer intervals without compromising monitoring quality. Finally, the third area, located in the Jaguaré neighborhood, was examined both in the field and in the laboratory using resistivity and induced polarization (IP) methods. The results revealed variations in geoelectrical signatures depending on contaminant concentration and biodegradation processes over time. These studies significantly contributed to the refinement of Conceptual Site Models, providing a robust foundation for understanding and managing the environmental conditions of each investigated region.
Keywords: Resistivity, Induced Polarization, Conceptual Site Model