use of ground work techniques for soil decontamination and ... use of ground work techniques for...

Use of ground work techniques for soil

decontamination and HaloCrete technique for

remediation using jet grouting

Intersol' 2017, International Conference on Soils, Sediments and Water,

March 14th-16th 2017

Cecilia Bohn, Keller Holding GmbH, Offenbach am Main, Germany

Peter Freitag, Keller Grundbau Ges. mbH, Vienna, Austria

Thomas G. Reichenauer, Austrian Institute of Technology, Tulln, Austria

Funded by the Federal Ministry of Agriculture, Forestry,

Environment and Water Management (BMLFUW);

Management by

Kommunalkredit Public Consulting GmbH

22

Outline

• General solutions for soil remediation

• Appropriate ground work techniques

• HaloCrete: in situ decontamination treatment for chlorinated

hydrocarbons using jet grouting technique

−Context

−Principle

−Laboratory tests

−Large scale field tests

• Conclusion/Outlook

General solutions for soil remediation

44

Parameters for choice of solution

• Type and amount of contaminant

• Ground water conditions

• Various chemical parameters

• Presence of structures on/in the contaminated ground

• …

55

Jet grouting / Grouting

Deep soil mixing

Compensation grouting

…

Vibrated or diaphragm wall

Deep soil mixing

Use of slurry and/or membrane

…

Possible solutions

Appropriate ground work techniques

77

Deep soil mixing

Cut-off wall with DSM, dike in Germany

88

Jet grouting Soilcrete®

Immobilization of oil pollution with jet grouting,

gas station in Austria

Excess

material

99

Cut-off wall with vibrated profile

Cut-off wall with vibrated profile,

dike in France

Overlapping zone

1010

Cut-off wall as diaphragm wall

Cut-off wall with membrane,

landfill containment, United Kingdom

HaloCrete: in situ decontamination for

chlorinated hydrocarbons treatment using

jet grouting technique

1212

Context

Chlorinated hydrocarbons (CHC):

• Solvent and degreasing agent

• Carcinogen

• Highly volatile

• Diffuses through concrete

• Dense-Non-Aqueous-Phase Liquid (DNAPL)

1313

Context

Non-permeable layer

Low permeability layer

CHC

Contaminant

Adsorbed contaminant

Evaporation

Dispersion

→ Complex distribution pattern

1414

Context

• Estimated 2000 polluted sites to be treated in Austria

• Origin of soil pollution in Austria (situation similar in other

european countries):

CHC

approx. 30 %

1515

Principle

In situ chemical reduction with zero-valent iron (nano particles)

→ at the end only chloride ions

and innoxious hydrocarbons

CHC (here

trichloroethylene

TCE)

1616

PrincipleZero-valent iron

Jet grouting technique

fulfills requirements:

• Contact iron/contaminant

• Good iron distribution

• Possible application under

buildings

• Sufficient soil stiffness and

strength after treatment

1717

Testing program

Phase 1:

Batch testsPhase 2:

Column testsPhase 3:

Field tests

• Presence of soil

• Washing-off effects

• Reaction in jet

grouting column

• Distribution of iron

inside column

section

• Interaction TCE/Iron

in presence of

binders

• Prove absence of

toxic by-products

1818

Laboratory tests: batch tests

Conclusions:

• Reduction reaction not negatively influenced by binders (7 tested)

• Clay-based additives have catalyzing effect (increase of degradation

reaction products / no adsorbtion)

1919

Laboratory tests: column tests

2020

Laboratory tests: column tests

0

10

20

30

40

50

60

70

0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25

mas

s fl

ow

[m

g]

Exchanged pore volumes [-]

Accumulated TCE mass flow

Treated 1 Treated 2 Treated 3

Reference 1 Reference 2 Reference 3

2121

Large-scale field tests

4 lysimeter chambers (Austrian Institute of Technology,

Seibersdorf)

2222

Pipes for groundwater

flow regulation

Permeable

layerl

Sampling

pointContaminant

injection

Ground water flow

HaloCrete column

Large-scale field tests

2323

Large-scale field tests

2424

Large-scale field tests

0

10

20

30

40

50

60

70

0 5 10 15 20 25 30

mas

s fl

ow

[m

g]

Exchanged pore volumes [-]

Accumulated TCE mass flow

Reference A

Reference C

Treated B

Treated D

Time of grouting

2525

Large-scale field tests

Treated Untreated (reference)

Compressive strength: all around 1 MN/m²

2626

Large-scale field tests

0.01

0.10

1.00

10.00

100.00

0 2 4 6 8 10

TCE

[mg/

kg d

ry w

eig

ht]

b-Carotin [mg/kg dry weight]

Correlation

b-Carotin/TCE

Reference A

Reference C

Treated B

Treated D

Factor

approx. 1000

(represents inital amout of TCE)

2727

Conclusion/Outlook

• Various ground work techniques have been used

successfully for soil remediation applications internationally

• HaloCrete jet grouting remediation of CHC

−Jet grouting technique fulfils requirements

−Efficiency proven based on lab and large-scale field tests

−Pilot project running

Thank you for your interest!

c.bohn@kellerholding.com