Evaluation of monitored natural attenuation as a bioremediation technique of benzene in the "Bois Saint-Jean" site

Abstract

The present thesis delves into the assessment of Monitored Natural Attenuation (MNA) as a viable bioremediation strategy within a contaminated region of Bois Saint-Jean. This area has been subjected to diverse remediation approaches, including In Situ Chemical Oxidation (ISCO), which significantly influences the site's hydrogeochemical dynamics. The primary objective of this study is to evaluate the potential of MNA in remediating benzene contamination in the context of the site's complex history. To achieve this, a comprehensive investigation encompassing major ions analysis, isotopic examination, and microbial assessment was undertaken.

The findings indicate the existence of promising biodegradation potential within certain sections of the site. Evidence from various analytical lines, including hydrogeochemical, isotopic, and microbial analyses, collectively suggest the occurrence of biodegradation processes. Notably, the implications of ISCO technique on the hydrogeochemistry of the site were identified, emphasizing the complexity of interpreting results in the wake of multiple remediation interventions.

However, it is important to note that the complexity of the site's history and the diverse remediation methods employed have rendered the interpretation of results a multifaceted challenge. The diverse array of evidence, although collectively indicative of biodegradation potential, does not uniformly align towards definitive conclusions. Consequently, drawing comprehensive and unequivocal inferences presents a notable challenge due to the intricate interplay of various factors.