Date:

ISTD

Method and design

Heating technologies

ISTD Method and Design / Krüger / May 2017 2

ComparisonTCH/ISTD - Heating

governed by thermal conductivity

ERH - Heating governed by electrical conductivity

SEE - Heating governed by hydraulic conductivity

Thermal conduction heating

ISTD Method and Design / Krüger / May 2017 3

500 – 800 °C 500 – 800 °C100 °C

Installation

ISTD Method and Design / Krüger / May 2017 4

References

ISTD Method and Design / Krüger / May 2017 5

Site Name Location Com-

pleted

Number

of heaters

Pro-

cess

Major COC Type(s) of

Soil

Target

temp.

oC

Pretreatment

concentration

[mg/kg]

Remedial

goal

[mg/kg]

Mean post-

treatment

concentration

[mg/kg]

Remedial

goals

achieved?

KvarnholmenStockholm,

SwedenOngoing 105 ISTD PCE/TCE

Crystaline

rock100 100 mg/l (1) <5 mg/l (1) - -

KongevejenVirum,

DenmarkOngoing 114 ISTD PCE/TCE Till clay 100 15 <0,1 - -

JärnsågenTrollhättan,

SwedenOngoing 60 ISTD

PCE, TCE,

cDCE

Crystaline

rock100

< 200 mg/l (1)

<9590 mg/m3 (2) 13 mg/l (1) - -

Danang Vietnam Ongoing (3) 1254 IPTDDioxin,

Herbicides

Silt and lake

sediments335 DNAPL <150 ppt

<10 ppt

Phase 1

Yes

Phase 1

Pont RougeMonthey,

Switzerland2016 144

ISTD +

SEE

Chlo. solvents,

Herbicides

Clay, silt

and gravel100 2,8-2.855 <0,3-50 ND - 0,37 Yes

Pilehøj

Vænge

Birkerød,

Denmark2015 45 ISTD TCE Till clay 100 DNAPL <0,1 0,011 Yes

Maarheeze Holland 2015 217 ISTDChlorinated

solvents

Silty/sandy

till100 DNAPL <0,2 0,1 Yes

ALBATaastrup,

Denmark2012 40 ISTD

Chlorinated

solventsTill clay 100 DNAPL <1 0,011 Yes

VadsbyvejHedehusene,

Denmark2011 24 ISTD

Chlorinated

solventsTill clay 100 10-100

Source

reduction0,6 Yes

ReerslevReerslev,

Denmark2009 147 ISTD PCE Till clay 100 DNAPL <1 0.012 Yes

SkuldelevSkuldelev,

Denmark2008 53 ISTD PCE

Clay, sand

and peat100 DNAPL <5 0.02 Yes

KnullenOdense,

Denmark2008 45

ISTD +

SEEPCE Till clay 100 DNAPL <5 0.51 Yes

Dyrup, P1VSöborg,

Denmark2007 6 ISTD Xylene Till clay 100 1100 None [pilot test] -

SkuldelevSkuldelev,

Denmark2006 4 ISTD PCE

Clay, sand

and peat100 500 None [pilot test] -

Notes: (1) Groundwater

(2) Air from borings

(3) First phase of 40.000 m3 completed - Phase 2 in operation

Design steps

ISTD Method and Design / Krüger / May 2017 6

• Basic design (Tender phase)

• Box model calculations based on geometry, geology, groundwater flow etc.

provides estimates on required power, number of heaters etc.

• Extraction strategy / temperature monitoring / pressure monitoring / pumping

• Numerical (layered) modelling with distributed groundwater flow and focus on

critical layers, insulation etc.

• Detailed design

• Site implications on heater placement

• Final modeling based on additional input

• Heater circuit balancing and layout

• Treatment design

Well layout

ISTD Method and Design / Krüger / May 2017 7

Site model

ISTD Method and Design / Krüger / May 2017 8

Layer 1

Layer 2

Layer 3

Layer 4

Layer 5

Layer 6

Layer 7

Layer 8

Kross

Siltig Morän

Siltig Morän / Grus

Lera

Sand och sandkalksten

Sand och sandkalksten

Sand och sandkalksten

Sand och sandkalksten

Heater Stickdown (~1.5 m)

TTZ –

Område 1

RH mbgs

0

1,5

2,5

4

8

18

20

21,5

25

GW

Normal

Heater

Section

TTZ –

område 2

Boosted

Heater

Section

Model input

ISTD Method and Design / Krüger / May 2017 9

Temperatures calculated

ISTD Method and Design / Krüger / May 2017 10

Layer 4-7 isTTZ

Extraction strategy

ISTD Method and Design / Krüger / May 2017 11

Extraction

ISTD Method and Design / Krüger / May 2017 12

Extraction

ISTD Method and Design / Krüger / May 2017 13

Steam/gas

Cooling

Water

Air

Pumpingwells