29 March 2007Intersol 2007, Paris, France1 Implementation of ISCO in soil remediation: lessons learned Thomas Keijzer PhD, Charles Pijls MSc & Martine

29 March 2007 Intersol 2007, Paris, France 1

Implementation of ISCO in soil remediation: lessons learned

Thomas Keijzer PhD, Charles Pijls MSc &

Martine van Gool MSc

Tauw bv, Deventer, the Netherlands


Tauw?

• Consultancy firm with offices in six European countries

including France (Tauw Environnement in Dijon, Lyon,

Douai & Paris)

• Focus lies on environmental quality & civil engineering

• Clients are among others (multinational) companies,

(local, regional & national) authorities, investors, lawyers

• So what do my colleagues and I do …?


So what do my colleagues and I do …?

• Find the best & cost-effective

remediation solution for each

individual site

ISCO Fenton’s

steam injection

excavation


Introduction

• Applied in the Netherlands (since 1999), started with

Fenton’s reagens currently persulphate is hot

• Popular• it is simple – inject an overdoses strong oxidant, when in

contact with a reduced specie e.g. a contaminant complete

degradation occurs• it is capable of large mass reduction• it is fast• no above ground waste treatment


Introduction

• ISCO includes applications of different oxidants, each

with its own field of application, contaminant situation,

and results that can be achieved

• Fenton’s reagens (classic & modified)• ozone (C-SpargeTM)• ozone/peroxide (PerozoneTM)• permanganate• persulphate (activated & non-activated)• solid peroxides (slow oxygen release compounds, ORC®)


Fenton’s reagens

© In Situ Technieken

© In Situ Technieken

© Tauw

© Tauw


Fenton’s reagens

• Fenton’s reagens• typically used in source zones • short remediation time (<2 yrs)• typically 2 injection periods• high level of safety required → restricted access

• Mass removal technique• mass removal typically between 70 and >95%• target values defined on groundwater concentration e.g. for

PCE 40 µg·L–1 are not advisable• high concentration in source zone remain after remediation

© KBBL


Fenton’s reagens | example

• PCE injection wells

1

10

100

1000

10000

100000

17 feb 19 mrt 18 apr 18 mei 17 jun 17 jul

datum

pe

r /µ

g.l-1

5352 5402 5403 5603 5802

1st

inje

ctio

nper

iod

2nd

inje

ctio

npe

riod

date

conc

entr

atio

n P

CE

/μ

g·l–

1

1

10

100

1000

10000

100000

17 feb 19 mrt 18 apr 18 mei 17 jun 17 jul

datum

pe

r /µ

g.l-1

5352 5402 5403 5603 5802

1st

inje

ctio

nper

iod

2nd

inje

ctio

npe

riod

date

conc

entr

atio

n P

CE

/μ

g·l–

1


example

shallow monitoring screens

deep monitoring screens

1

10

100

1000

10000

100000

02 Mar 02 May 02 Jul 01 Sep 01 Nov 01 Jan

datum

per

/µg.

l-1

4001, 4.5-5.5 4002, 3,5-4,5 4004, 4-5 4005, 3-4

date

conc

entr

atio

n P

CE

/μ

g·l–

1

1

10

100

1000

10000

100000


datum

per

/µg.

l-1

4001, 4.5-5.5 4002, 3,5-4,5 4004, 4-5 4005, 3-4

date

conc

entr

atio

n P

CE

/μ

g·l–

1

1

10

100

1000

10000


datum

per

/µg.

l-1

4001, 7-8 4002, 6-7 4004, 7-8 4005, 7-8

date

conc

entr

atio

n P

CE

/μ

g·l–

1

1

10

100

1000

10000


datum

per

/µg.

l-1

4001, 7-8 4002, 6-7 4004, 7-8 4005, 7-8

date

conc

entr

atio

n P

CE

/μ

g·l–

1


Fenton’s reagens | lessons learned

• Results• mass reduction 55 - 99% e.g. 5403; 63,000 → 3,500 µg·L–1

• results in monitoring wells not conclusive:

favourable e.g. 4004, 4-5; 66,000 → 16,000 µg·L–1

unfavourable soil sampled approx. 1 m from injector 5352 with

mass reduction 96%; 34,000 → 1,400 µg·L–1

contained 710 mg·kg–1 PCE

• mobilisation / displacement due to injection of large volumes

• soil chemistry – SOD of lesser importance, buffer capacity and

Fe(II) availability governing


Ozone & ozone/peroxide

© Tauw

© Verhoeve Milieu © Tauw


Ozone | C-SpargeTM

• Ozone • continues co-injection of O3 in an adapted air sparging system

• typically used in reduction of groundwater plumes

… sometimes used in source zones without DNAPL• extended remediation time (3-5 yrs)

• high level of safety required → O3 production on-site

• Concentration reduction technique• target values defined on groundwater concentrations e.g. for

PCE 40 µg·L–1 (or lower) are realistic


Ozone/peroxide | PerozoneTM

• Ozone/peroxide • co-injection of O3 & hydrogen peroxide in an adapted air sparging

system• typically used in source zones without DNAPL

… also used in reduction of groundwater plumes• extended remediation time (3-5 yrs)

• high level of safety required → O3 production on-site

• Mass / concentration reduction technique• target values defined on groundwater concentrations e.g. for PCE

40 µg·L–1 (or lower) are realistic• mass reduction typically 70 and >99%


Ozone/peroxide | example 1

• Degradation of Mecoprop, source zone

0

10

20

30

40

50

60

0 10 20 30 40 50 60 70 80 90 100

time /d

con

cen

tra

tion

Me

cop

rop

/µg

/l

4001 (7,5 m) 4003 (5 m) 4000 (3,5 m) 4002 (2,5 m)

Fit 4001(7,5 m) Fit 4003 (5 m) Fit 4000 (3,5 m)

injection period

fits based on t½=20 d


example 2

• TCE & cDCE

source zone

(no DNAPL)0

500

1,000

1,500

2,000

2,500

3,000

3,500

12/jul/2004 12/aug/2004 12/sep/2004 13/okt/2004 13/nov/2004

datum

conc

entr

atio

n T

CE

& c

DC

E /

µg·

l-1

TCE cDCE TCE target cDCE target

0

1,000

2,000

3,000

4,000

5,000

6,000

12/jul/2004 12/aug/2004 12/sep/2004 13/okt/2004 13/nov/2004

datum

conc

entr

atio

n T

CE

& c

DC

E /

µg·

l-1


2051, 3.0-4.0 m bgl

2053, 6.5-7.5 m bgl


Ozone/peroxide | lessons learned

• Results• mass reduction 80 - >95% • results in monitoring further down gradient or deeper

disappointing (no effect)

• processes known from air sparging are of importance e.g.

radius of influence, convection, preferential (air) flow paths,

soil heterogeneity

• soil chemistry – SOD of lesser importance rule of thumb

approx. 15 g O3 needed per m3 soil


Permanganate

© Tauw© Tauw

© Tauw© Tauw


Permanganate

• Permanganate• typically used in source zones

… not cost-effective in plume areas• used in low (2-4%) solutions • short remediation time (<2 yrs)• stable (mild) oxidant → less rebound•

• Mass / concentration reduction technique• mass removal typically between 70 and >95%• target values defined on groundwater concentration• can be used as polishing step after e.g. Fenton’s

© Tauw


0

500

1,000

1,500

1/nov/2005 2/dec/2005 2/jan/2006 2/feb/2006

date

conc

entr

atio

n /µ

g·l-1


example

• TCE & cDCE

reduction in

source zone

(no DNAPL)

0

500

1,000

1,500

2,000

2,500

3,000

1/nov/2005 2/dec/2005 2/jan/2006 2/feb/2006

date

conc

entr

atio

n /µ

g·l-1


2001, 3.0-4.0 m bgl

2022, 5.5-6.5 m bgl


Permanganate | example

• Soil heterogeneity

coarse sand

coarse sand

coarse sand

coarse sand

clay

fine sand

fine sand

upw

ards grad

ing

26 cm

top

coarse sand

coarse sand

coarse sand

coarse sand

clay

fine sand

fine sand

coarse sand

coarse sand

coarse sand

coarse sand

clay

fine sand

fine sand

upw

ards grad

ing

26 cm

top

© Tauw

!

© Tauw


ave

rag

e S

OD

kg

·m–3

0,5

1,0

0O3 MnO4S2O8 H2O2 •OH

ave

rag

e S

OD

kg

·m–3

0,5

1,0

0O3 MnO4S2O8 H2O2 •OH

• Results• reduction groundwater concentrations sufficient, over-all results

disappointing often 2 injection periods necessary

• soil heterogeneity

important parameter

• soil chemistry – SOD crucial

rule of thumb inject excess

MnO4 to overcome all SOD

• soil reactivity high compared

to US references

Permanganate | lessons learned

(Brown, 2003)


Selection ISCO technique

DNAPL?

source area

nuisance

yes

time frameno

permanganateor ozone/peroxide

ozoneozone/peroxide

Fenton’s reagens

<1 year

>1 year

issue

no issue

DNAPL?

no

yes


Summarising

• ISCO is not a silver bullet solution

→ ISCO part of a complete remediation strategy

• Limiting factors• remediation target values

→ technique and site specific• soil heterogeneity

→ where is the contaminant going? oxidant?

→ specific soil survey & optimal selection of injection system• soil chemistry

→ do laboratory test on site samples

→ pilot remediation



Fenton’s reagens | contaminants

group specific contaminants

TPH light TPH-fraction, alkenes

heavy TPH-fraction, alkanes

CHC PCE, TCE, DCE & VC, chlorobenzenes,

chlorophenols

Tetra, Chloroform, 111TCA & 112TCA, PCB’s,

aromatic

compounds

BTEX, naphthalene, phenols,

light PAH’s (2 / 3-ring)

heavy PAH’s (>4-ring)

other MTBE


Ozone & ozone/peroxide | contaminants


TPH light TPH-fraction, alkenes

heavy TPH-fraction, alkanes


chlorophenols

Tetra, Chloroform, 111TCA & 112TCA, PCB’s,

pesticides (POP’s)

aromatic

compounds

BTEX, naphthalene, phenols,

light PAH’s (2 / 3-ring)

heavy PAH’s (>4-ring)

other MTBE


Permanganate | contaminants


TPH alkenes

TPH, alkanes


chlorophenols

Tetra, Chloroform, 111TCA & 112TCA, PCB’s

aromatic

compounds

toluene, xylenes, phenols

benzene

PAH’s

other cyanides

!

Documents

29 March 2007Intersol 2007, Paris, France1 Implementation of ISCO in soil remediation: lessons learned Thomas Keijzer PhD, Charles Pijls MSc & Martine