Field, Laboratory and Modeling Evidence for Strong Attenuation of a Cr(VI) Plume in a Mudstone Aquifer Due to Matrix Diffusion and Reaction Processes

This study uses a combination of conventional and high-resolution field and laboratory methods to investigate processes causing attenuation of a hexavalent chromium (Cr(VI)) plume in sedimentary bedrock at a former industrial facility. Groundwater plume Cr(VI) concentrations decline significantly due to matrix diffusion and reaction processes. The research examines the physical and chemical interactions occurring between the contaminants and the geological materials within the aquifer. Findings from field experiments reveal that the diffusion of Cr(VI) into sedimentary layers results in reduced concentrations in groundwater, demonstrating the effectiveness of natural attenuation mechanisms. Furthermore, laboratory experiments complement field results by confirming reactions that enhance the removal of Cr(VI) from the aqueous phase. The combined approach of field data and laboratory tests strengthens the argument for the potential management strategies for contaminated sites. The implications of these findings suggest that understanding the processes responsible for contaminant attenuation can inform better remediation practices and policies to address groundwater contamination issues. Ultimately, this study underscores the importance of integrating field and laboratory methodologies to enhance our understanding of subsurface contaminant behavior.