1. Surfactant Flushing An Innovative Ground Water Remediation Technology Jeffrey H. Harwell Asahi Glass Chair of Chemical Engineering The University of Oklahoma, Norman Principal, Surbec Environmental, LLC

2. Basics Release NAPL from aquifer pores Release NAPL from aquifer pores Direct and Indirect Food Additives Direct and Indirect Food Additives Surfactants pass EPA biodegradation testing Surfactants pass EPA biodegradation testing Used throughout the United States Used throughout the United States US patents 6,913,419 and 7,021,863 US patents 6,913,419 and 7,021,863

3. What is a surfactant? Molecule fits between oil and water Molecule fits between oil and water Common and safe Common and safe Found in Found in –Salad dressing –Toothpaste –Mouthwash –Shampoo

4. How does it work? NAPLs contaminate ground water NAPLs contaminate ground water Droplets become immobile Droplets become immobile –Trapped by surface tension –Force that traps water in a paper towel Surfactants go to oil/water interface Surfactants go to oil/water interface –Lower surface tension –Release droplets –Like removing grease from pants in laundry Newly mobile NAPL extracted with pumps Newly mobile NAPL extracted with pumps

5. Trapped-drop... becomes released …and is pumped to surface

6. Column Comparison Ground Water Food Surfactant Laundry Surfactant “Designer” blend of surfactants

7. 7 / 57 Trapping Curves

8. 8 / 57 Mobile Portion of NAPL in Pores without Surfactant System Capillary Number without Surfactant

9. 9 / 57 Mobile Portion of NAPL in Pores with Surfactant System Capillary Number with Surfactant System Capillary Number without Surfactant

10. Observations Trapped NAPL can be mobilized by Trapped NAPL can be mobilized by –increasing water pore velocity –increasing water viscosity –lowering interfacial tension Surbec reduces interfacial tension Surbec reduces interfacial tension –3 to 4 orders of magnitude –very low concentrations (< 1wt %)

11. How Is It Delivered? NAPL Pool Injection Wells Extraction Wells

13. Surfactant Flushing Integrated Process RW IW AC AS NAPL WASTE STORAGE Disposal O/W Separator Mixer Raw S