11

Thermal Remediation Services, Inc.

Thermal Remediation Services, Inc.

Electrical Resistance Heating for

In-Situ Remediation of Soil & Groundwater

December 10, 2002

Greg Beyke(770) 794-1168

gbeyke@thermalrs.comwww.thermalrs.com

2

SOLVENT

SAND

CLAY

BEDROCK

WATER TABLE

GROUNDWATER FLOW

2

3PCU

3

4GAC Filter

4

55

Why Electrical Resistance Heating?

Why Electrical Resistance Heating?

! Heating is uniform with no bypassed regions

! Heating is rapid � months vs. years! Steam is produced in-situ! Preferentially heats tight soil lenses and

DNAPL hot spots! Cost effective: most commercial, full-

scale sites range from $40-$100 per yds3

! Heating is uniform with no bypassed regions

! Heating is rapid � months vs. years! Steam is produced in-situ! Preferentially heats tight soil lenses and

DNAPL hot spots! Cost effective: most commercial, full-

scale sites range from $40-$100 per yds3

66

ApplicationsApplications

� Low permeability & heterogeneous lithologies� DNAPL & LNAPL cleanups by aquifer and

smear zone heating� Heavy hydrocarbon mobilization� Degradation enhancement (hydrolysis, bio)� Remediation underneath operating facilities, in

the presence of buried utilities and hazardous waste drums

� Low permeability & heterogeneous lithologies� DNAPL & LNAPL cleanups by aquifer and

smear zone heating� Heavy hydrocarbon mobilization� Degradation enhancement (hydrolysis, bio)� Remediation underneath operating facilities, in

the presence of buried utilities and hazardous waste drums

77

In-Situ Steam Generation

In-Situ Steam Generation

HEATEDZONE

ELECTRODE ELECTRODENEUTRAL

2. Steam generation is uniformthrough the heated zone

1. Soil grains act as electricalresistors

150 V to600 V

<15 V

3. Discrete intervals can be heated

88

Surface EquipmentSurface Equipment

Steam Condenser

500 kW PCU

Operating Electrode

Photo Courtesy of Brown and Caldwell

99

Vapor Recovery System

Vapor Recovery System

ERH Power Control Unit

Water Storage TankOr Sewer

VacuumPump

Carbonor

Catox

Condenser

1

23

4

5 6

T

T

>99% of the contaminant mass

remains in the vapor state

1010

ERH Equipment Staging

ERH Equipment Staging

Baker Tank

500 kW PCU Steam Condenser

GAC Vessels Vacuum

Blower

CPVC pipe from wells

1111

Full-Scale DNAPL Cleanup the Problem*

Full-Scale DNAPL Cleanup the Problem*

� DNAPL (TCE & TCA) covering about 1 acre of an industrial site

� ENSR performed remediation for about 5 years and removed 30,000 pounds of TCE & TCA

� DNAPL remained in four areas, mostly under a large warehouse building

� Goal: Reach Tier III RBCA Cleanup Levels over entire site

� DNAPL (TCE & TCA) covering about 1 acre of an industrial site

� ENSR performed remediation for about 5 years and removed 30,000 pounds of TCE & TCA

� DNAPL remained in four areas, mostly under a large warehouse building

� Goal: Reach Tier III RBCA Cleanup Levels over entire site

*Data from the 1999 EPA Cost and Performance Report

1212

Full-Scale DNAPL Cleanup Site Map*Full-Scale DNAPL Cleanup Site Map*

10� deepwastedrain

Cast ironroof drain

TCE and TCAtanks

Storm drain

Power Control Unit

Semiconductor Building

DNAPL

107 electrodes

*Data from *Data from 1999 EPA 1999 EPA Cost and Cost and

Performance Performance ReportReport

1313

ERH Remediation Beneath a BuildingERH Remediation

Beneath a Building

Electrode

Vapor Recovery Pipe

Limited overhead

access

Photo Courtesy of Brown and

Caldwell

1414

Full-Scale DNAPL CleanupSubsurface Cross-SectionFull-Scale DNAPL CleanupSubsurface Cross-Section

BuildingSlab

Fill

7�

20�

HeatedZone

Electrode

Sandy Silt

SiltyClay

DNAPL

SVEWell

Clay Aquitard

SVEWell

DNAPL Pools

Electrode

18�

1515

Full-Scale DNAPL CleanupOperations & Results*

Full-Scale DNAPL CleanupOperations & Results*

Operations� Heating (107 electrodes) started June

4, 1998� Aquifer reached boiling in 60 days� Maintained above the boiling point of

TCE (73ºC) for the next 3 monthsResults

� Tier III levels by late November 1998; the site is now closed

� >15,000 pounds of VOCs removed

Operations� Heating (107 electrodes) started June

4, 1998� Aquifer reached boiling in 60 days� Maintained above the boiling point of

TCE (73ºC) for the next 3 monthsResults

� Tier III levels by late November 1998; the site is now closed

� >15,000 pounds of VOCs removed *Data from 1999 EPA Cost and Performance Report*Data from 1999 EPA Cost and Performance Report

1616Average Groundwater

Concentrations Seven Most Contaminated Wells*

Average Groundwater Concentrations Seven Most

Contaminated Wells*

March 1998

November 1998

cis 1,2-DCE 1,1,1-TCA TCE0

5,000

10,000

15,000

20,000

25,000

30,000

35,000

40,000

ug/l

98.3% 99.9% 98.9%

October 1998*Data from *Data from 1999 EPA 1999 EPA Cost and Cost and

Performance Performance ReportReport

1717

0.0

0.5

1.0

1.5

2.0

2.5

3.0

3.5

4.0

mg/l

Aa6 Ba3 D3 D7 D9 E5 F9 F13 G3 ave

Monitoring Wells

May-99Dec-99May-00

Do Groundwater Concentrations Rebound after

ERH Remediation?

Do Groundwater Concentrations Rebound after

ERH Remediation?

Average Additional Decrease

= 23%

two wells increased

seven wells decreased

Data from Data from ENSR reportENSR report

1818

Polishing MechanismsPolishing Mechanisms

� Hydrolysis of Halogenated Alkanes� Compounds such as TCA have a hydrolysis half-life of

less than one day at steam temperatures.

� Iron Reductive Dehalogenation� Steel shot used as electrode backfill provides an iron

source for reductive dehalogenation (iron filing wall)

� Temperature Accelerates Reactions� The above reaction rates are increased by factor of

thousands at 100°C (Arrhenius Equation)

� Bioremediation by Thermophiles� Thermophilic bacteria are the most effective solvent

dehalogenators and prefer 40-70°C

� Hydrolysis of Halogenated Alkanes� Compounds such as TCA have a hydrolysis half-life of

less than one day at steam temperatures.

� Iron Reductive Dehalogenation� Steel shot used as electrode backfill provides an iron

source for reductive dehalogenation (iron filing wall)

� Temperature Accelerates Reactions� The above reaction rates are increased by factor of

thousands at 100°C (Arrhenius Equation)

� Bioremediation by Thermophiles� Thermophilic bacteria are the most effective solvent

dehalogenators and prefer 40-70°C

1919

Full Scale DNAPL CleanupCost & Performance Data*Full Scale DNAPL CleanupCost & Performance Data*

� Effectiveness� Total operations took 18 weeks, five days� Treated approximately 30,000 cubic yards� Since completing, average groundwater VOC

concentrations have continued to decrease

� Costs� Total project costs were $32/cubic yard� The total includes electrical costs of $6.50/cubic yard� Vapor treatment was not required. If vapor treatment

had been required, the cost would have been about $41 per cubic yard.

� Effectiveness� Total operations took 18 weeks, five days� Treated approximately 30,000 cubic yards� Since completing, average groundwater VOC

concentrations have continued to decrease

� Costs� Total project costs were $32/cubic yard� The total includes electrical costs of $6.50/cubic yard� Vapor treatment was not required. If vapor treatment

had been required, the cost would have been about $41 per cubic yard.

*Data from the 1999 EPA Cost and Performance Report*Data from the 1999 EPA Cost and Performance Report

2020

TCE DNAPL RemediationAir Force Plant FourFort Worth, Texas

TCE DNAPL RemediationAir Force Plant FourFort Worth, Texas

Photo Courtesy of

URS

2121

ERH Remediation BeneathAir Force Plant Four

ERH Remediation BeneathAir Force Plant Four

SVE pipingelectric

al cable electrode

SVE well

Photo Courtesy of

URS

2222

Lowry Landfill System Layout

Lowry Landfill System Layout

South Waste Pit

2000 kW PCU

Thermal Oxidizers

Cables to the Electrode

Field

Electrode Field