Reaction and Transport Processes Controlling In Situ Chemical Oxidation of DNAPLs

Abstract : In situ chemical oxidation involves the introduction of chemical oxidants into the subsurface to destroy organic contaminants in soil and ground water, with the goal being to reduce the mass, mobility, and/or toxicity of contamination. The objective of this project was to quantify the pore/interfacial scale DNAPL reactions and porous media transport processes that govern the delivery of oxidant to a DNAPL-water interface and degradation of the DNAPL. In this project, an integrated set of tasks were carried out involving a comparative analysis focused on contrasting oxidant types (permanganate and catalyzed hydrogen peroxide) and oxidant application methods (low to high dose concentrations and delivery densities) to treat a mixture of tetrachloroethene (PCE) and trichloroethene (TCE) DNAPL present in mass levels and distributions under conditions representative of a range of subsurface environmental settings. The research also addressed the potential secondary effects of applications of ISCO, as well as the coupling of ISCO with pre- and post-ISCO treatment operations.