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