PNNL

Abstract

A multi-dimensional, multi-species reactive transport code, RT3D, was used to aid in the analysis of natural attenuation design at the Dover AFB site. The RT3D code is a general-purpose numerical solver that can be used to solve any type of reactive transport systems by specifying a system-specific reaction model (Clement, 1997; Clement et al., 1998). In this study, a detailed biochemical reaction model was developed to simulate all aerobic and anaerobic reactions that occur at the Dover AFB site. The reactions were integrated into RT3D and the resulting numerical code was used to simulate the bioreactive transport occurring at the site. Through a model calibration process, field-scale decay rates of PCE/TCE and their degradation products were estimated. The calibrated model also successfully recreated the observed distribution of PCE, TCE, DCE, VC and chloride plumes. Sensitivity analysis of the calibrated model was performed to quantify the importance of model parameters. The simulation model developed in this work is a useful framework for analyzing chlorinated-solvent natural attenuation data.