Numerical simulation of density-driven permanganate oxidation of trichloroethylene DNAPL in a sandy aquifer

Numerical models of permanganate oxidation of chlorinated solvents TCE and PCE have been developed to integrate field-measured data, test conceptual models, and assist in the design of field experiments. The reactive transport code MIN3P was modified to simulate geochemical reactions in variable-density flow systems. Three-dimensional simulations were created of a pilot-scale permanganate oxidation trial. In this experiment, the density of the permanganate solution was the primary mechanism driving the migration of the oxidant. Reaction by-products and geochemical parameters were monitored using depth-discrete nested sampling points over an eight-month period. Chemical processes simulated in the model include DNAPL dissolution, permanganate oxidation of TCE and aquifer organic carbon, calcite dissolution, and precipitation of manganese oxides. The model generally reproduces the field-measured movement of the oxidant, the production of chloride, and the destruction of TCE DNAPL.