Using CSIA for Biodegradation Assessment: Potential, Practicalities and Pitfalls

Using CSIA for Biodegradation Assessment: Potential, Practicalities and Pitfalls

B. Sherwood LollarUniversity of Toronto

S. Mancini, M. Elsner, P. Morrill, S. Hirschorn,N. VanStone, M. Chartrand, G. Lacrampe-Couloume,E.A. Edwards, B. SleepG.F. Slater

CSIA as Field Diagnostic Tool

Environmental Forensics:(Philp)

Biodegradation& Abiotic Remediation (BSL)

EPA 600/R-08/148

Restoration Technology Transfer

Fundamental PrinciplesStandard Methods & QA/QCDecision Matrices

Outline

• FAQ: Common Pitfalls/Misconceptions• Source Differentiation• What is Fractionation?• Verification of MNA and/or Enhanced

Remediation using CSIA– Fingerprint of biodegradation?

• Where to be Careful• CSIA as Early Warning System &

Diagnostic Tool – Case study

FAQ Sheet

• Sample collection: adaptation of standard 40 mL VOA vial

• Turnaround: approximately 4 weeks• Cost: less than cost of one additional

monitoring well - can reduce uncertainty & risk, and drive decision making

• QA/QC: more than 50 year history of standardization and cross-calibration

• Tracer: but naturally occurring

Commercial CSIA (currently ~ a dozen labs worldwide)

• C most widely available (H, Cl)

• Petroleum hydrocarbons (including both aromatics and alkanes)

• Chlorinated ethene and ethanes

• Chlorinated aromatics

• MTBE and fuel oxygenates

• PAHs, PCBs, pesticides

Compound Specific Isotope AnalysisCompound Specific Isotope Analysis

Natural abundance of two stable isotopes

of carbon: 12C and 13C

CSIA measures R or isotope ratio

(13C/12C) of individual contaminant

x 100013C in ‰ =(13C/ 12C sample – 13C/ 12Cstandard)

13C/ 12C standard

Source differentiation of TCE

-35

-33

-31

-29

-27

-25

ACP PPG DOW ICI

Source/Manufacturer

13C

(‰

) Slater et al. (1998)van Warmerdam et al. (1995)

DATA FROMJendrzejewski et al. (2001)

MI

Principles of Fractionation

to - Before degradation

t1 - Post degradation

Preferential degradationof T12CE

T12CE

Remaining TCE progressivelyisotopically enriched in 13Ci.e. less negative 13C value

T12CE T12CE

T12CE

T12CET12CE

T12CE

T12CE

T12CE

T12CE

T13CET13CE

T13CE

T13CE

T13CE

T13CE T12CE

k12C > k13C

Sherwood Lollar et al. (1999)

-35

-30

-25

-20

-15

-10

0 0.2 0.4 0.6 0.8 1

Fraction of TCE remaining

13C

(in

‰)

Sherwood Lollar et al. (1999)Org. Geochem. 30:813-820

Biodegradation of TCE

Increasing Biodegradation

R = RR = Roo f f (α – 1)(α – 1)

0

5

10

15

20

25

0 250 500 750 1000 1250 1500

Hours

Ch

lori

nat

ed e

then

e (i

n u

mol

es)

cisDCE

TCE

VC

Ethene

Slater et al. (2001)ES&T 35:901-907

-80

-70

-60

-50

-40

-30

-20

-10

0

10

20

0 250 500 750 1000 1250 1500

Hours

13C

Ch

lori

nat

ed e

then

e

cisDCETCE VC

Ethene

Slater et al. (2001)ES&T 35:901-907

Fractionation of Daughter Products

• Breakdown Products – initially more negative 13C values than the compounds from which they form

• Products subsequently show isotopic enrichment trend (less negative values) as they themselves undergo biodegradation

• Combining parent and daughter product CSIA is valuable (a recurring theme …)

CSIA: Verification of Degradation

• Chlorinated ethenes (Hunkeler et al., 1999; Sherwood Lollar et al., 1999; Bloom et al., 2000; Slater et al., 2001; Slater et al., 2002; Song et al., 2002; Vieth et al., 2003, Hunkeler et al., 2004; VanStone et al., 2004; 2005; Chartrand et al., 2005; Morrill et al., 2005; Lee at el., 2007; Liang et al, 2007)

• Chlorinated ethanes (Hunkeler & Aravena 2000; Hirschorn et al. 2004; Hirschorn et al., 2007; VanStone et al., 2007; Elsner et al., 2007)

• Aromatics (Meckenstock et al., 1999; Ahad et al., 2000; Hunkeler et al., 2000, 2001; Ward et al., 2001; Morasch et al., 2001, 2003; Mancini et al. 2002, 2003; Griebler et al., 2003; Steinbach et al., 2003)

• MTBE (Hunkeler et al., 2001; Gray et al., 2002; Kolhatkar et al., 2003; Elsner et al., 2005, Kuder et al., 2005; Zwank et al., 2005; Elsner et al., 2007; McKelvie et al., 2007)

Biotic and Abiotic Degradation

• Chlorinated ethenes (Hunkeler et al., 1999; Sherwood Lollar et al., 1999; Bloom et al., 2000; Slater et al., 2001; Slater et al., 2002; Song et al., 2002; Vieth et al., 2003, Hunkeler et al., 2004; VanStone et al., 2004; 2005; Chartrand et al., 2005; Morrill et al., 2005; Lee at el., 2007; Liang et al, 2007; Elsner et al. 2010)

• Chlorinated ethanes (Hunkeler & Aravena 2000; Hirschorn et al. 2004; Hirschorn et al., 2007; VanStone et al., 2007; Elsner et al., 2007)

• Aromatics (Meckenstock et al., 1999; Ahad et al., 2000; Hunkeler et al., 2000, 2001; Ward et al., 2001; Morasch et al., 2001, 2003; Mancini et al. 2002, 2003; Griebler et al., 2003; Steinbach et al., 2003)

• MTBE (Hunkeler et al., 2001; Gray et al., 2002; Kolhatkar et al., 2003; Elsner et al., 2005, Kuder et al., 2005; Zwank et al., 2005; Elsner et al., 2007; McKelvie et al., 2007)

CSIA as Restoration Tool

• Isotopic enrichment in 13C in remaining contaminant (less negative 13C values) a dramatic indicator of biodegradation

• Extent of fractionation predictable and reproducible – Quantification (rates) possible in many cases

• CSIA can distinguish mass loss due to the strong fractionation in degradation (biotic and abiotic)

• versus small- or non-fractionating processes such as volatilization, diffusion, dissolution, sorption , etc.

Non-conservative vs. Conservative

Degradatio

n

% contaminant remaining

Non-degradative

100 75 50 25

Ch

an

ge in

13C

/12C

0


Degradatio

n


Non-degradative

100 75 50 25

Ch

an

ge in

13C

/12C

0

Fractionation isabout breaking Bonds

100 255075

Degradatio

n

0

Non-degradative



Ch

an

ge in

13C

/12C

Where to be careful

• Processes that drive towards low fraction remaining (air sparging)

• High Kow; high TOC (sorption)• Vadose zone (volatilization)• Hydrogen isotope effects can be larger• Fractionation is a function of different

microbial pathways (e.g. aerobic versus anaerobic)

• Be an informed customer

Case Study I: CSIA as early warning system for bioremediation: Kelly AFB

P. Morrill, G. Lacrampe-Couloume, G. Slater, E. Edwards, B. Sleep, B. Sherwood Lollar, M.

McMaster and D. Major

JCH (2005) 76:279-293

Early Warning System

• Stable carbon isotopes have potential to provide significant added value in early stages of biodegradation

• Monitoring 13C values of PCE and TCE may provide evidence of degradation prior to breakdown products such as VC and ethene rising above detection limits for VOC

Morrill et al. (2005)

Case Study II: CSIA to trouble-shoot potential

cisDCE stall

M. Chartrand, P. Morrill, G. Lacrampe-Couloume, and

B. Sherwood Lollar

ES&T (2005) 39:4848-4856

CSIA at Fractured Rock Site

0

6

18

24

30

36

40

12

Dep

th B

elow

Gro

und

Sur

face

(m

)

0 m 120 mground water flow direction

5B/T 1B 2B 3B 4B

fill

silt & peat

clay

till

fracturedbedrock

SUPPORT PILES

Manufacturing Building

A A`

Disposal well

6B

DNAPL0

6

18

24

30

36

40

12

Dep

th B

elow

Gro

und

Sur

face

(m

)

0 m 120 mground water flow direction

5B/T 1B 2B 3B 4B

fill

silt & peat

clay

till

fracturedbedrock

SUPPORT PILES


A A`

Disposal well

6B

DNAPL

A`

N

Approximate ground water flow direction under undisturbed conditions


Disposal Well

Well 7B

Well 5B/T

Well 2B

Well 1B

Well 3B

Excavation Activities

Ground water flow direction in pilot treatment area during isotope study (June - November 2002)

0 20m

Approximate Scale

Estimated TCE Plume

N N

Approximate ground water flow direction under undisturbed conditions


Disposal Well

Well 7B

Well 5B/T

Well 6B

Well 2B

Pilot Treatment Area

Well 1B

Well 3B

Well 4B

Excavation Activities

Ground water flow direction in pilot treatment area during isotope study (June - November 2002)

0 20m

Approximate Scale

Estimated TCE Plume

A

Chartrand et al. (2005) ES&T 39:4848-4856

Fluctuation in VOC

0

10

20

30

40

50

60

70

80

2/2

8/0

1

4/1

9/0

1

6/8

/01

7/2

8/0

1

9/1

6/0

1

11

/5/0

1

12

/25

/01

2/1

3/0

2

4/4

/02

5/2

4/0

2

7/1

3/0

2

9/1

/02

10

/21

/02

12

/10

/02

Sampling Date

Co

nce

ntr

atio

n (

mg

L

-1)

Biostimulation

BioaugmentationBegin Isotope

Study

Nov-02Sep-02Jul-02Jun-02Mar-02Mar-01 May-01 Jul-01 Sep-01 Nov-01 Jan-02 Apr-02Feb-01

Sampling Date

VC

TCE

cisDCE

ETH

Chartrand et al. (2005)

CSIA as Diagnostic Tool

• Initial apparent successful production of VC and ethene

• Confused and potentially compromised by fluctuations in hydrogeologic gradients

• Periodic spikes in cisDCE & VC due to – Incomplete reductive dechlorination?– Dissolution (rebound) from NAPL phase?– Mixing of groundwater?


Fluctuation in VOC

0

10

20

30

40

50

60

70

80

2/2

8/0

1

4/1

9/0

1

6/8

/01

7/2

8/0

1

9/1

6/0

1

11

/5/0

1

12

/25

/01

2/1

3/0

2

4/4

/02

5/2

4/0

2

7/1

3/0

2

9/1

/02

10

/21

/02

12

/10

/02

Sampling Date

Co

nce

ntr

atio

n (

mg

L

-1)

Biostimulation


Study


Sampling Date

VC

TCE

cisDCE

ETH

VC

cisDCE


Continued 13C enrichment despite VOC fluctuations

-30

-25

-20

-15

-10

Jun-02 Jul-02 Sep-02 Nov-02

Sampling Date

δ13C

(‰

)

well 2B

well 4B

well 3B

well 5B

Continuing Biodegradationof cisDCE

Cha Chartrand et al. (2005)

Fluctuation in VOC

0

10

20

30

40

50

60

70

80

2/2

8/0

1

4/1

9/0

1

6/8

/01

7/2

8/0

1

9/1

6/0

1

11

/5/0

1

12

/25

/01

2/1

3/0

2

4/4

/02

5/2

4/0

2

7/1

3/0

2

9/1

/02

10

/21

/02

12

/10

/02

Sampling Date

Co

nce

ntr

atio

n (

mg

L

-1)

Biostimulation


Study


Sampling Date

VC

TCE

cisDCE

ETH

VC

cisDCE


Continuing Net Biodegradation

-50

-40

-30

-20

-10

Jun-02 Jul-02 Sep-02 Nov-02

Sampling Date

δ13C

(‰

)

well 2B

well 5B

well 3B

well 2B

well 4B

VC

Ethene


CSIA as Restoration Tool

• Verification of remediation – direct evidence for transformation

• Sensitive tracer – early warning system• Cost effectiveness - diagnostic for trouble-

shooting and optimization (Chartrand et al., 2005; Morrill et al 2009)

• Quantification of remedial effectiveness (Morrill et al., 2005; Hirschorn et al. 2007)

• Resolution of Abiotic versus Biotic degradation for chlorinated solvents (VanStone et al., 2008; Elsner et al. 2008; 2010)

More information?

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Using CSIA for Biodegradation Assessment: Potential, Practicalities and Pitfalls

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