VII Seminário Internacional Sobre Remediação e Revitalização … · VII Seminário Internacional Sobre Remediação e Revitalização de Áreas Contaminadas São Paulo, 21.10.2010,

VII Seminário Internacional Sobre Remediação e Revitalizaçãode Áreas Contaminadas São Paulo, 21.10.2010, 1/7

VII Seminário Internacional SobreRemediação e Revitalizaçãode Áreas Contaminadas

São Paulo, 21.10.2010

Dr.-Ing. Uwe Hiester (reconsite GmbH)Dr.-Ing. Hans-Peter Koschitzky, Dipl.-Ing. (FH) Oliver Trötschler (VEGAS – Research Facility for Subsurface Remediation, Uni Stuttgart)Dr.-Ing. Frank Holzer, Dr.-Ing. Ulf Roland (Helmholtz Centre for Environmental Research, Leipzig)

Thermally Enhanced In Situ Source Zone Removal

21. Oct. 2010 Seite 2Thermally enhanced in situ source zone removal

Oilphase


• in-situ sourceremoval

• organiccontaminantsboiling point up to app. 200°C

• LNAPL & DNAPL

• non cohesive & cohesive soil

• unsat. & satur. zone

Silt

DNAPLLNAPL

Groundwater

Loam

Sand

Application of thermally enhanced in-situ remediation


0,01

0,1

1

10

100

0 14 28 42 56 70 84 98 112 126 140 154

Time [d]

CVO

C-M

ass

Flux

from

Sou

rce

Zone

1 [k

g/d]

'cold' SVE Okt.1998 - Mar.1999'cold' SVE June 2009

Comparison ‘cold‘ SVE with THERIS


Comparison ‘cold‘ SVE with THERIS

0,01

0,1

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100

0 14 28 42 56 70 84 98 112 126 140 154

Time [d]

CVO

C-M

ass

Flux

from

Sou

rce

Zone

1 [k

g/d]

'cold' SVE Okt.1998 - Mar.1999'cold' SVE June 2009THERIS (only SB26) June-Okt. 2009


Conventional ‘cold‘ SVE

Altenbockum et al. 1997groundwater

sand

sand, filling

loam, marl, silt

conta-mination

SVE

continuousoperation

intermittentoperation

conc

entr

atio

n

conc

entr

atio

n

time time

initialconcentration c0

conventional soil vapor extraction (SVE):usually several years of operation



Thermally enhanced SVE

groundwater

sand

sand, filling

loam, marl, silt

conta-mination Target:

• liquid contaminant (10 °C)⇒ gaseous phase

• short remediation time

THERIS = Thermally enhanced in-situ remediation with thermal wells

HE HE

SVETHE: 500°C • soil vapor extraction (SVE)

• air treatment system


200

300

400

500

600

700

800

900

1000

60 80 100Temperature [°C]

Stea

m P

ress

ure

[mba

r]

Tetra-chloro-ethen (PCE)

co-boilingPCE and Water

Water

Boiling of water and contaminant phase

∼ 60%

0

200

400

600

800

1000

0 25 50 75 100 125Temperature [°C]

Stea

m P

ress

ure

[mba

r]

Tetra-chloro-ethen (PCE)

co-boilingPCE and Water

Water


Thermally enhanced in-situ remediation

• convective heat supply into soil layer withgood to high permeability e.g. sand

Steam- (Air-) Injection (TUBA-method)

• direct heat generation e.g. in dry or humid sand

Radio frequency

• conductive heat supply into soil layer moderate to low soil permeablility, e.g. silt, loam, clay

Thermal wells (THERIS-method)


Steam-Air Injection: Field of Applicationvadoze zone:high to medium permeability(gravel to sandy silt)

saturated zone:porous aquifersK: 5 x 10-5 to 1 x 10-3 m/s(sand -> silt) for

thermal range in saturated zone:

K: 0,5 – 5 x 10-4 m/s radial steam propagation:

3 - 5 m in radius for 150 kg/h steam (120 kW)

the higher anisotropy thewider steam propagation


test field after completion of

installation (February 2007)

test field during operation (June 2007)

injection well

Remediation goals of the pilot in-situ remediationhorizontal radial steam expansion > 2.5 m in the saturated zonereduction of benzene concentration in soil vapor > 99%removal of contaminant mass > 95%

to be achieved during six months (1600 m³ of soil)

Zeitz - Impressions From The Pilot Field


1„cold“SVE

2air-

sparging

3 steam-air-injection

4 cooling (SVE)

target temperature

target average temperature in subsurface > 75°C

Zeitz - Heating Of The Subsurface



138

139

140

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149

565 570 575 580415

420425

430

YX

Z

temperature1009590858075706560555045403530252015100

I3 I1GWL1

I2EK1EK4 EK3

EK5

EK2

288 h

Injection UZ: I1 + I2 day 12

138

139

140

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565 570 575 580415

420425

430

YX

Z

temperature1009590858075706560555045403530252015100

I3 I1GWL1

I2EK1EK4 EK3

EK5

EK2

1056 h

Injection UZ: I1 + I2 + I3 + EK3 day 44

UZSZ

UZSZ

injection in extraction well EK3to steam the vadoze zone

138

139

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149

565 570 575 580415

420425

430

YX

Z

temperature1009590858075706560555045403530252015100

I3 I1GWL1

I2EK1EK4 EK3

EK5

EK2

1536 h

Injection SZ: I1, Start I2 day 20

138

139

140

141

142

143

144

145

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149

565 570 575 580415

420425

430

YX

Z

temperature1009590858075706560555045403530252015100

I3 I1GWL1

I2EK1EK4 EK3

EK5

EK2

2244 h

Injection SZ: I1 + I2 day 50

“thermal radius” ~ 5m

symmetricsteam propagation

operation of two wells

target radial steam extension > 2.5 m in the saturated zone

temp1009590858075706560555045403530252015100

Temp. [°C]

Zeitz - Heat Propagation


0

10

20

30

40

50

60

70

80

0 7 14 21 28 35 42 49 56 63 70 77 84 91 98 105

112

119

126

133

140

147

154

161

168

175

182

189

196

203

210

217

224

231

238

245

time [d]

benz

ene

SV

E [g

/m³]

0

1000

2000

3000

4000

5000

6000

7000

8000

02.05. 21 h

16.05. 21 h

30.05. 21 h

13.06. 21 h

27.06. 21 h

11.07. 21 h

25.07. 21 h

08.08. 21 h

22.08. 21 h

05.09. 21 h

19.09. 21 h

03.10. 21 h

17.10. 21 h

31.10. 21 h

14.11. 21 h

28.11. 21 h

12.12. 21 h

26.12. 21 h

cum

ulat

ive

mas

s be

nzen

e [k

g]

benzene (g/m³) in soil vapourBL-Pegel Benzen (g/m³)benzene (kg) cumulative masslog. decline benzene SVE (g/m³)

Phase 1: (SVE) 2130 kgPhase 2: (AS) 4050 kg Phase 3.1 (UZ): 6330 kgPhase 3.2 (SZ): 6630 kgPhase 3.3 (SZ+UZ): 6710 kg Phase 3.4 (UZ): 6766 kgPhase 4 (AS-AV): 6868 kg

regression curve"cold" soil vapour extraction

I1I1+I2

I1 - I3

I1u

I1u+ I2upulsed SAI7h on, 1 h off

I1u+ I2uI1o + I3o

I1o+ I3oI2u + EK3

pulsing air injection

steam-air injection (SAI) UZ, Phase 3.1

SAI saturated zone (SZ)Phase 3.2

coolingPhase 4

SAI SZ + UZPhase 3.3

SVEPhase 1

ASPhase 2

SAI UZPhase 3.4

SVE: 60 -> 200 kg/h

AS I1+

ASI3

I1o I2o

I1o + I2o + I3o +EK3 SAI (I1u) SAI (I1u+I2u) --> entire field intermittent and pulsingair venting, sparging + SVE

ASI1

UZ (silt)SVE + SAI

Air Venting

Air Sparging

target reduction of benzene concentration in soil vapor > 99%

Zeitz - Mass Extraction of Benzene by SVE


reduction of benzene concentration in SVE by 99% removal of more than 99% in soil (soil vapour-soil eq. KOC-method)0.16 mg benzene / kg soilsoil sampling eight months after steam-air injection confirmed 0.1 mg/kg for unsaturated zone and 0.5 mg/kg including saturatedzone

Indication of Remediation Progress by SVE


effective heating to exceed target temperatureeffective, fast & wide-ranging steam propagation in saturated zone

Heating of Subsurface

mass extraction by „cold“ SVE and air-sparging (59% of total mass) remediation target achieved by SI (35% of total mass in 13 weeks)minor mass of Benzene in saturated zone: approximately 300 kg (~ 4%)

Remediation Progress

mass removal: more than 99% of Benzene extracted (6,75 to Benzene)groundwater: reduction of benzene concentrations by 75%

Remediation goals

Zeitz - Summary


Applied electrode geometries- Parallel plate or net-shaped electrodes- Arrays of rod-like electrodes(optional: also used as extraction wells)

- Radio-wave antenna

Similar to microwave ovenfast re-orientation of polar molecules(e.g. water) or other polar structuresin the external electrical field

interaction within the materialheat formation

OH

Hδ+ δ− δ− δ+

- + + -OH

Hδ+ δ− δ− δ+

- + + -

RFgenerator

Match-box

380 V 50 Hz

T>250°Cpossible

13.56 MHz

Set up and working principle of dielectric soil heating


RF unit

RF generator(15 kW, 13.56 MHz)

Cooling system

Process control system

Fibre-opticalsensors

Gas analysis

Power measurement

PLF supply(12 kW, 50 Hz)

RF unit

Flexible PE - Hose

Measuring section V, T, p, c

Manifold

RF

-

Shielding

ElectrodeE1

ElectrodeE5

Matchbox

Coaxialcable

Catalyticoxidation

RF unit

RF generator(15 kW, 13.56 MHz)

Cooling system

Process control system

Fibre-opticalsensors

Gas analysis

Power measurement

PLF supply(12 kW, 50 Hz)

RF unit

Flexible PE - Hose


Manifold

RF

RF unit

Flexible PE - Hose


Manifold

RF

-

Shielding

ElectrodeE1

ElectrodeE5

Matchbox

Coaxialcable

Catalyticoxidation

coaxial cablesensors for p, T, V, c

.

shielding

matchbox

up to 50 temperature sensors9 points for vapour sampling

4 electrodes / extraction wells

Arrangement for ISRFH project

3 mElectrodedistance

ISRFH with a modular RF system



RW electrode and extraction section(200 mm diameter)

- 5.8 m

-5.3 m

-3.8 m

Filtration sand

Bore hole Ø273 mm

FRP pipeØ 237 mm

- 0.50 mConcrete

Bentonite

RW electrode and extraction section(200 mm diameter)

- 5.8 m

-5.3 m

-3.8 m

Filtration sand

Bore hole Ø273 mm

FRP pipeØ 237 mm

- 0.50 mConcrete

Bentonite

Electrode / extraction wellSite characterization

Soil: very inhomogeneous

Groundwater table: 8.5 m bgl.

Lignite: > 9 m bgl.

Treatment of the unsaturatedzone between 3 and 7 m bgl.

Contamination:mainly benzene < 3.5 g/kgvariety of aromatic andaliphatic VOC

ISRFH – new electrode design


0 20 40 60 80 100 120 1400

50

100

150

200

250

300

20

40

60

depth

3 m5 m7 m

VOC

con

c.or

g. C

/ m

3

Time / days

Start RF heating

Tem

pera

ture

/ °C

-5 -4 -3 -2 -1 0 1 2 3 4 57

6

5

4

3

2

1

0

Distance from the RF-Electrode / m

Dep

th /

m

0

20

40

60

80

100

Tem

pera

ture

/ °C

Temperature profile

Heat transport supported by SVERadius of influence up to 5 m

VOC concentrationTemperature distribution in a soil volume of about 300 m3 after 60 d RF heating with 15 kW

Increase in VOC concentrationby a factor of 4 to 8

ISRFH with a modular RF system


The demonstration project consisted of three stages:1. „cold“ SVE (24 days), 2. RF heating alone (18 days)3. combined SVE + RFH (36 days)

App. 300 m3 were heated to a mean temperature of 54°C.

The radius of influence for RF heating was about 5 m.

SVE supported heat transport in the soil.

Extraction of VOCs was significantly enhanced by heating althoughquantification was difficult due to interference with the soil around thedemonstration site (1.3 tonnes were eliminated).

ISRFH – Main Results


Site D: BTEX-petr. hydrocarbon remediation

groundwater

sand

filling

clayey finesand

THERIS-remediation


Site D: BTEX-petr. hydrocarbon remediation

surroundingSVE-wells

Thermal wells

central SVE-wells




64 d THERIS

Factor 100 inmass recovery


0

20

40

60

80

100

120

0 180 360 540 720 900 1.080 1.260 1.440 1.620 1.800 1.980 2.160

remediation time [days]

mas

s re

cove

ry [k

g]

0 6 12 18 24 30 36 42 48 54 60 66 72

THERIS mass removal'cold' SVE mass removal (extrapolation)furhter operation time with 'cold' SVE to recover the THERIS contaminant mass (supposed constant mass flux for cold SVE)

Monday, 30.07.2008:

min. 54 month (=4.5 years) further 'cold' SVE operation needed to recover the same mass from THERIS pilot test

THERIS BTEX-remediation

additional costs for ‘cold‘ SVE to recover the same contaminant mass:

constant mass flux ~ 4,5 years ~ 120.000 £

half mass flux (av. over time) ~ 9 years ~ 300.000 £


Remediation Area


THERIS application

workshop

storeage

office

parkingarea

shop


Workshop Area


Street View



Treatment Container


Online Measurement Systems


Online Measurement Systems


Total VOC-mass flux

0

1

2

3

4

5

6

7

8

-14 0 14 28 42 56 70 84 98 112 126 140 154 168 182 196

Time [d]

daily

CH

C-m

ass

flux

[kg/

d] total CHC mass flux sumtotal CHC mass flux BL5total CHC mass flux BL4total CHC mass flux BL3total CHC mass flux BL2total CHC mass flux BL1total CHC mass flux BL2btotal CHC mass flux BL1b

050

100150200250

-14 0 14 28 42 56 70 84 98 112 126 140 154 168 182 196

Dis

char

ge[m

³/h] BL5 BL4 BL3 BL2 BL1 BL2b BL1b

Mass flux BL1 – BL5 [kg]


Soil Vapour Contamination [mg/m³]


Before THERIS 2 month THERIS

6 month THERIS4 month THERIS



TUBA-THERIS-TUBA combination @ industrial site

THERIS-remediation

clay

clay

TUBA-remediation

sand

-6 m

-12 m

-18 m

TUBA-remediation

Aquifer 1

Aquifer 2

thermalwells

steam-air-injection

steam-air-injection


Temperatures after 80 days

deep

intermediate

shallow


Workshop usage during THERIS remediation

0

1

10

100

1.000

10.000

CVOC CVOC CVOC BTEX, petr.hydroc.

CVOC

site A site B site C site D site E

spec

ific

ener

gy c

onsu

mpt

ion

per r

ecov

ered

con

tam

inan

t mas

s [k

Wh/

kg]

cold' SVE at the beginningTHERIS


Evaluation of the technology

Eurodemo sustainability demands:

• processes understood

• results from applications are well documented

• high contaminant extraction rates

• fast decontamination

• costs & environmental impacts are significantly less


Conclusions

• Thermally enhancements can be efficiently applied forthe in-situ remediation of the unsaturated and thesaturated zone.

• Thermally enhancements can enable a continuedusage of the building during remediation.

• Thermally enhancements consume less energythan ‘cold‘ SVE.

• The quality of site evaluation effects thequality of the design.

• The remediation goals can effect the efficiency.


reconsite GmbHAuberlenstrasse 13D-70736 Fellbach

Dr.-Ing. Uwe HiesterPhone: +49 (0)711-410190-11Fax: +49 (0)711-410190-19

http://www.reconsite.comE-mail: [email protected]

Documents

VII Seminário Internacional Sobre Remediação e Revitalização … · VII Seminário Internacional Sobre Remediação e Revitalização de Áreas Contaminadas São Paulo, 21.10.2010,