Surfactant Flushing An Innovative Ground Water Remediation Technology Jeffrey H. Harwell Asahi Glass Chair of Chemical Engineering The University of Oklahoma,

Surfactant Flushing

An Innovative Ground Water An Innovative Ground Water Remediation TechnologyRemediation Technology

Jeffrey H. HarwellAsahi Glass Chair of Chemical EngineeringThe University of Oklahoma, NormanPrincipal, Surbec Environmental, LLC

Basics

Release NAPL from aquifer pores Release NAPL from aquifer pores Direct and Indirect Food AdditivesDirect and Indirect Food Additives Surfactants pass EPA biodegradation testingSurfactants pass EPA biodegradation testing Used throughout the United StatesUsed throughout the United States US patents US patents 6,913,419 and 7,021,8636,913,419 and 7,021,863

What is a surfactant?

Molecule fits between Molecule fits between oil and wateroil and water

Common and safeCommon and safe Found inFound in

– Salad dressingSalad dressing– ToothpasteToothpaste– MouthwashMouthwash– ShampooShampoo

How does it work?

NAPLs contaminate ground waterNAPLs contaminate ground water Droplets become immobile Droplets become immobile

– Trapped by surface tensionTrapped by surface tension– Force that traps water in a paper towelForce that traps water in a paper towel

Surfactants go to oil/water interfaceSurfactants go to oil/water interface– Lower surface tensionLower surface tension– Release dropletsRelease droplets– Like removing grease from pants in laundryLike removing grease from pants in laundry

Newly mobile NAPL extracted with pumpsNewly mobile NAPL extracted with pumps

Trapped-drop . . . becomes released

…and is pumped to surface

Column ComparisonGround Water

FoodSurfactant

LaundrySurfactant

“Designer” blend of surfactants

7 / 57

TrappingCurves

8 / 57

Mobile Portionof NAPL in Pores withoutSurfactant

System Capillary Number withoutSurfactant

9 / 57

Mobile Portionof NAPL in Pores withSurfactant

System Capillary Number withSurfactant

System Capillary Number withoutSurfactant

Observations

Trapped NAPL can be mobilized byTrapped NAPL can be mobilized by– increasing water pore velocityincreasing water pore velocity– increasing water viscosityincreasing water viscosity– lowering interfacial tensionlowering interfacial tension

Surbec reduces interfacial tension Surbec reduces interfacial tension – 3 to 4 orders of magnitude3 to 4 orders of magnitude– very low concentrations (< 1wt %)very low concentrations (< 1wt %)

How Is It Delivered?

NAPL Pool

Injection Wells

Extraction Wells

SB-1

SB-2

SB-3

SB-4

SB-5

SB-6

Remediation Well System Layout with Well Numbers

5 PPM

0’ 50’ 100’

17.0’

18.0’

IW1 IW2 IW3 IW4

IW5 IW6

IW7 IW8 IW9 IW10IW11 IW12

IW13 IW14 IW15

IW16 IW17 IW18 IW19 IW20 IW21

IW22 IW23 IW24

IW26IW25 IW27 IW28IW29

IW30

IW31 IW32

EW1 EW2EW3

EW4EW5

EW6

EW7 EW8 EW9

EW10 EW11 EW12

Surfactant Flushing Integrated Process

RW IW

AC

AS

NAPL

WASTE STORAGE

Disposal

O/WSeparator

MixerRaw S