THE EFFECTS OF FLOW-RATE AND SOLUTE CONCENTRATION ON THE FATE AND TRANSPORT OF CHLORINATED SOLVENTS THROUGH CORES OF BEREA SANDSTONE

Recently, the EPA called for research to characterize the environmental fate and transport of chemicals used in hydraulic fracturing. One of the most ubiquitous chemicals used in this field are highly chlorinated solvents which have been shown to travel through porous bedrock. The transport of these chemicals in similar systems is also of major concern at many DOD and DOE sites. In this study, a series of lab tests were conducted to determine the fate and transport parameters for highly chlorinated solvents through water saturated cylinders of Berea Sandstone rock core. These studies utilized a unique setup where a hydrostatic core-holder housed 2 inch diameter by 1 to 8 inch long cores. Aqueous solutions of the target solutes along with conservative anionic tracers were passed through the rock using a high pressure pump and measured in-line continuously using a UV-detector. In these studies, we uniquely focused on the impact of flowrate, solute concentration, and permeability and porosity on transport. In addition, hand samples were collected to evaluate potential degradation products of the highly chlorinated solvents using GCMS. The results have shown the effects of rate-limited sorption. Degradation of the solvents was un-common due to the relatively short residence times within the system. While more work is needed, these results show the potential for this experimental approach.