Mathematical Modeling of In Situ Chemical Oxidation with Permanganate - Model Development and Sensitivity Analyses

Abstract

In situ chemical oxidation (ISCO) using permanganate can be a very effective technique for remediating groundwater and soil contaminated by chlorinated solvents. Injected reagent must be delivered to contaminated zone for successful clean up in ISCO. Many of current remediation projects using chemical oxidation system are less effective than desired because of poor delivery of the chemical reagents to the treatment zone. A variety of site specific factors can affect reagent delivery including the amount of oxidant injected, volume of water injected, aquifer heterogeneity, and natural oxidant demand (NOD). A model was developed and validated for simulating the transport and reaction of permanganate in the subsurface for ISCO. Six different kinetic relationships with zero, 1st, and 2nd order reaction were examined to identify the kinetic equation which best predicts the consumption of permanganate in experimental incubations. The numerical model RT3D was modified to simulate ISCO by developing module that simulates reactions between permanganate, NOD and contaminants. The newly developed RT3D model was used to calibrate an ISCO pilot test at MMR. Calibrated model provided an adequate match to the field data demonstrating this approach is appropriate for simulating ISCO of groundwater contaminants. A sensitivity analysis with validated model examined the influence of aquifer conditions and design variables on treatment efficiency.