U.S. Patent Awarded to GLMAC Researcher Dr. Kurt Pennell

Bachman Road Project Update

U.S. Patent Awarded to GLMAC Researcher Dr. Kurt Pennell

US Patent #6099206 was issued to GLMAC Researcher Dr. Kurt Pennell, Associate Professor of Civil and Environmental Engineering at the Georgia Institute of Technology, in August 2000 for Density Modified Displacement to Remediate Contaminated Aquifers. Density Modified Displacement (DMD) is a method for groundwater remediation of DNALP-contaminated aquifers comprising the steps of modifying the density of the DNALP with alcohol and displacing the NAPL by surfactant flushing. For more information on DMD, please select from the following links:

Description of the DMD process

Power point presentation of data slides (coming soon!)

Time lapse photography of DMD process (coming soon!)

GLMAC investigators were awarded $1.5 million by the Michigan Department of Environmental Quality (MDEQ) to implement Phases II and III of the remediation project at the Bachman Road Site in Oscoda, Michigan. The overall goal of the project is to evaluate the effectiveness of halorespiration and surfactant-enhanced remediation to clean up two separate plumes at the site, which is contaminated with chlorinated solvents (predominantly tetrachloroethylene (PCE)) and petroleum hydrocarbons. Results from Phase I site characterization and laboratory feasibility studies will be used to design (Phase II) and execute (Phase III) pilot-scale field demonstrations of both technologies for the two contaminant plumes.

Phase I of the surfactant-enhanced aquifer remediation (SEAR) project focused on characterizing the dense non-aqueous phase liquid (DNAPL) source zone and selecting a surfactant that promotes the solubilization of the residual-phase DNAPL. Analysis of aquifer samples confirmed that a non-aqueous phase PCE source region exists at the site. Although no PCE pools were detected, their existence is likely considering the concentration and sandy nature of the formation and the physical characteristics of the contaminant. Tween 80, a biodegradable, non-toxic, solubilizing surfactant, was selected for site SEAR application based on its performance in laboratory sand box flushing tests using contaminated Bachman aquifer material.

Phase I of the halorespiration project focused on characterizing the dechlorination activity of indigenous halorespirers and determining conditions for effective bioaugmentation of halorespiration. The presence of native halorespirers was demonstrated in intermediate and deep aquifer regions. Two distinct dechlorination activities were identified at the site: in the intermediate region PCE was converted to dichloroethene (cis-DCE), while in the deep aquifer region PCE was completely dechlorinated to ethene. Laboratory bioaugmentation columns indicated that dechlorination activity of both laboratory strains and Bachman halorespirers could be transferred to previously inactive aquifer material, increasing natural dechlorination rates by 50-60%.

In Phase II of the project, investigators will apply the information obtained in Phase I to the design of pilot-scale field demonstrations. Upon MDEQ approval of the test design, the proposed remediation strategy for both technologies will be implemented in Phase III.