tetra tech nus, inc. overview of presentation · beta-elimination 6.6 mg/l pathway acetylene,...
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1
Implementation of a Nanoscale Zero Valent Iron Remediation Demonstration
Keith W. Henn, P.G., Tetra Tech NUS, Inc.
U.S. EPA Workshop on Nanotechnology for Site Remediation
October 20, 2005
Dan Waddill, PE, PhD. NAVFAC EFD South
Tetra Tech NUS, Inc.
October 20052
Overview of presentation
ØØOverview of Nanoscale IronOverview of Nanoscale Iron
ØFull Scale Pilot Study, NAS Jacksonville
ØSummary and Conclusions
2
~10-600 nm
Noble Metal
Pd
Base Metal
Fe0
Noble Metals: - forms galvanic cells - catalyze hydrogenation
Base metal - Electron donor
C2 Cl3 C2H6 + 3Cl-
Fe2+
e-
Dehalogenation Schematic
Nanoscale Zero Valent Iron
Source: modified after Lehigh University
Other Contaminants•Chlorinated VOCs•Nitrates•Metals (e.g, Cr, As)•Chlorinated Pesticides
October 20054
Ø Small area (1050 sq ft)
Ø Utility corridor
Ø Geology• Silty to fine sand from
0 to 24 feet bgs• Dense clay from 24 to
54 ft bgs
Ø Hydrogeology• Flow toward southeast• Water table at 7 feet bgs
• Hyd. Conduct. ~2 ft/day
Site BackgroundMW-28
MW-39
MW-01MW-38
MW-32
MW-36
MW-31
MW-30
MW-34
MW-33
0 5 10 15
MW-29
MW-37
Groundwater flow direction
N
MW-8
3
Site Contamination SummaryHangar 1000, NAS Jacksonville
GW Flow
Maximum Total VOC550 mg/kg in soil80 mg/L in groundwater
Chemical oxidation conducted in 2001
October 20056
Full Scale Pilot Study Design
Source: U.S. Navy
• Remedial Goal as defined in the Work Plan– Reduce contaminant mass 40 to 50%– Not expected to reach groundwater MCLs– MNA anticipated as next step
• How much iron is needed?– Reaction Capactity (VOCs : Nano Fe) = ~1:5-10 by wt.– CVOC mass estimated: 42 to 125 lbs– Need an estimated 210 to 1250 lbs– Injected 300 lbs
• Two injection methods:– Strategic DPT injections– Recirculation Process
4
Tetra Tech NUS, Inc.
October 20057
Recirculation Setup
October 20058
Nanoscale Iron– Polymer Supported
w/Palladium Catalyst– No carbon substrate
5
October 2005
Recirculation:Hydraulic Results
Before(Dec 29th)
After(Jan 23rd)
•Keep iron in source
•Good mixing
•Good iron distribution
During(Jan 21st)
Source Well H10MW37
Molar Concentrations
Chlorinated Ethene
0
2 5
5 0
7 5
100
125
150
12/20
/03
01/02
/04
01/15
/04
01/28
/04
02/10
/04
02/23
/04
03/07
/04
03/20
/04
04/02/
04
04/15
/04
04/28/
04
05/11/
04
05/24
/04
06/06/
04
06/19
/04
07/02
/04
07/15
/04
07/28
/04
08/10
/04
08/23
/04
09/05
/04
09/18
/04
10/01
/04
10/14
/04
10/27
/04
11/09
/04
11/22
/04
12/05
/04
12/18/
04
Date
Mo
lar
Co
nce
ntr
atio
n (
uM
/L)
ETHENE+ETHANE
VC
CIS-1,2-DCE
TCE
PCE
Injections #1 and #2
0 3 6 9 12 Months
Chlorinated Ethane
0
5
10
15
20
25
30
12/20
/03
01/02
/04
01/15
/04
01/28
/04
02/10
/04
02/23
/04
03/07
/04
03/20
/04
04/02
/04
04/15
/04
04/28
/04
05/11
/04
05/24
/04
06/06
/04
06/19
/04
07/02
/04
07/15
/04
07/28
/04
08/10
/04
08/23
/04
09/05
/04
09/18
/04
10/01
/04
10/14
/04
10/27
/04
11/09
/04
11/22
/04
12/05
/04
12/18
/04
Date
Mo
lar
Co
nce
ntr
atio
n (
uM
/L)
Injections #1 and #2
0 3 6 9 12 Months
ETHENE+ETHANE
1,2-DCA
VC
1,1-DCE
CA
1,1-DCA
1,1,1-TCA
6
Source Well H10MW34
Molar Concentrations
Chlorinated Ethene
0
25
50
75
100
12/20/
03
01/02/
04
01/15
/04
01/28/
04
02/10/
04
02/23/
04
03/07/
04
03/20/
04
04/02/
04
04/15/
04
04/28/
04
05/11/04
05/24/
04
06/06/
04
06/19/04
07/02/
04
07/15/
04
07/28/04
08/10/
04
08/23
/04
09/05/04
09/18/
04
10/01
/04
10/14/
04
10/27/
04
11/09
/04
11/22
/04
12/05/
04
12/18
/04
Date
Mo
lar
Co
nce
ntr
atio
n (
uM
/L)
ETHENE+ETHANE
VC
CIS-1,2-DCE
TCE
PCE
Injections #1 and #2
0 3 6 9 12 Months
Chlorinated Ethane
0
2
4
6
8
10
12
14
16
18
20
12/20
/03
01/02/
04
01/15/
04
01/28
/04
02/10/
04
02/23/
04
03/07
/04
03/20
/04
04/02/
04
04/15/
04
04/28/
04
05/11/
04
05/24/
04
06/06
/04
06/19
/04
07/02/
04
07/15/
04
07/28/
04
08/10/
04
08/23/
04
09/05/
04
09/18
/04
10/01
/04
10/14/
04
10/27/
04
11/09/
04
11/22/
04
12/05/
04
12/18
/04
Date
Mo
lar
Co
nce
ntr
atio
n (
uM
/L)
ETHENE+ETHANE
1,2-DCA
VC1,1-DCE
CA1,1-DCA
1,1,1-TCA
Injections #1 and #2
0 3 6 9 12 Months
Butane
0
1
2
3
4
5
12/20
/03
01/05
/04
01/21
/04
02/06
/04
02/22
/04
03/09
/04
03/25
/04
04/10
/04
04/26
/04
05/12
/04
05/28
/04
06/13
/04
06/29
/04
07/15
/04
07/31
/04
08/16
/04
09/01
/04
09/17
/04
10/03
/04
10/19
/04
11/04
/04
11/20
/04
12/06
/04
12/22
/04
Time
Con
cent
ratio
ns (
mg/
L)
Injections #1 and #2
6.6 mg/LBeta-Elimination Pathway
Acetylene, Butane, & Isobutane
Isobutane
0
0.1
0.2
12/20
/03
01/05
/04
01/21/
04
02/06/04
02/22
/04
03/09
/04
03/25
/04
04/10/
04
04/26/04
05/12/04
05/28
/04
06/13
/04
06/29
/04
07/15/
04
07/31/04
08/16/
04
09/01
/04
09/17
/04
10/03
/04
10/19/
04
11/04/04
11/20/
04
12/06
/04
12/22
/04
Time
Con
cent
rati
ons
(mg/
L)
Injections #1 and #2
0 3 6 9 12 Months
Acetylene
0
1
2
3
4
12/20
/03
01/05
/04
01/21
/04
02/06
/04
02/22
/04
03/09
/04
03/25
/04
04/10
/04
04/26
/04
05/12
/04
05/28
/04
06/13
/04
06/29
/04
07/15
/04
07/31
/04
08/16
/04
09/01
/04
09/17
/04
10/03
/04
10/19
/04
11/04
/04
11/20
/04
12/06
/04
12/22
/04
01/07
/05
Time
Co
nce
ntr
atio
ns
(mg
/L)
Injections #1 and #2
0 3 6 9 12 Months
Isobutane
7
October 200513TCE isoconcentrations
Round 1 (baseline)
October 200514
Round 3 (after inject)
TCE isoconcentrations
8
October 200515TCE isoconcentrations
Round 11 (after inject)
Dissolved Oxygen
0
0.5
1
1.5
2
2.5
3
12/20
/03
01/05
/04
01/21
/04
02/06
/04
02/22
/04
03/09
/04
03/25/
04
04/10
/04
04/26
/04
05/12
/04
05/28
/04
06/13
/04
06/29
/04
07/15/
04
07/31/
04
08/16/
04
09/01
/04
09/17
/04
10/03
/04
10/19/
04
11/04
/04
11/20/
04
12/06
/04
12/22
/04
Time
Co
nce
ntr
atio
ns
(mg
/L)
Injections #1 and #2
Geochemistry Results
Oxygen & ORP
H10MW10 (upgradient well)
H10MW32 (source well)
H10MW34 (source well)
H10MW37 (source well)
H10MW38 (down grad. well)
H10MW39 (down grad. well)
0 3 6 9 12 Months
Oxidation-Reduction Potential
-350
-250
-150
-50
50
150
250
12/20
/03
01/05
/04
01/21
/04
02/06
/04
02/22/
04
03/09
/04
03/25
/04
04/10
/04
04/26
/04
05/12
/04
05/28
/04
06/13/
04
06/29
/04
07/15
/04
07/31
/04
08/16
/04
09/01
/04
09/17
/04
10/03
/04
10/19
/04
11/04
/04
11/20
/04
12/06/
04
12/22
/04
OR
P (
mill
ivo
lts)
Injections #1 and #2
0 3 6 9 12 Months
9
H10MW10 (upgradient well)
H10MW32 (source well)
H10MW34 (source well)
H10MW37 (source well)
H10MW38 (down grad. well)
H10MW39 (down grad. well)
Geochemistry Results
Dissolved Iron & Sulfate
Dissolved Iron
0
2000
4000
6000
8000
10000
12000
14000
12/20
/03
01/05
/04
01/21
/04
02/06
/04
02/22
/04
03/09
/04
03/25
/04
04/10
/04
04/26
/04
05/12
/04
05/28
/04
06/13
/04
06/29
/04
07/15
/04
07/31
/04
08/16
/04
09/01
/04
09/17
/04
10/03
/04
10/19
/04
11/04
/04
11/20
/04
12/06
/04
12/22
/04
Time
Co
nce
ntr
atio
ns
(ug
/L) 26,000 ug/L
Injections #1 and #2
0 3 6 9 12 Months
Sulfate
0
5
10
15
20
25
12/20
/03
01/05
/04
01/21
/04
02/06
/04
02/22
/04
03/09
/04
03/25
/04
04/10
/04
04/26
/04
05/12
/04
05/28
/04
06/13
/04
06/29
/04
07/15
/04
07/31
/04
08/16
/04
09/01
/04
09/17
/04
10/03
/04
10/19
/04
11/04
/04
11/20
/04
12/06
/04
12/22
/04
01/07
/05
Time
Co
nce
ntr
atio
ns
(mg
/L)
Injections #1 and #2
0 3 6 9 12 Months
H10MW10 (upgradient well)
H10MW32 (source well)
H10MW34 (source well)
H10MW37 (source well)
H10MW38 (down grad. well)
H10MW39 (down grad. well)
Carbon Dioxide
0
50
100
150
200
250
12/20
/03
01/05
/04
01/21
/04
02/06
/04
02/22
/04
03/09
/04
03/25
/04
04/10
/04
04/26
/04
05/12
/04
05/28
/04
06/13
/04
06/29
/04
07/15
/04
07/31
/04
08/16
/04
09/01
/04
09/17
/04
10/03
/04
10/19
/04
11/04
/04
11/20
/04
12/06
/04
12/22
/04
Time
Conce
ntrat
ions
(mg/L
)
Injections #1 and #2
0 3 6 9 12 Months
Geochemistry Results
Carbon Dioxide, Methane& pH (stable from 6-7)
Methane
0
500
1000
1500
2000
2500
3000
12/20
/03
01/05
/04
01/21
/04
02/06
/04
02/22
/04
03/09
/04
03/25
/04
04/10
/04
04/26
/04
05/12
/04
05/28
/04
06/13
/04
06/29
/04
07/15
/04
07/31
/04
08/16
/04
09/01
/04
09/17
/04
10/03
/04
10/19
/04
11/04
/04
11/20
/04
12/06
/04
12/22
/04
01/07
/05
Time
Co
nce
ntr
atio
ns
(ug
/L)
Injections #1 and #2
4750 ug/L
0 3 6 9 12 Months
10
October 200519
Is there evidence for biological activity?Ø qPCR analysis for Dehalococcoides (GC/ML)
conducted in 3 wells:
1.65174H10MW39
25 U500 UH10MW37
18500 UH10MW10
12 months after injection(GC/ML)
Baseline(GC/ML)
Well
October 200520
Soil Sampling SummaryPercent change: Soil data before & after study
BLUE/Gray - indicated INCREASE in concentration
RED/Yellow - indicates DECREASE in concentration
25%88%94%75%92%92%8%11%Total % Change
18%-71%-11%174%1026%-267%cis-1,2-DCE
--------Vinyl chloride
--100%-100%-100%-100%-96%141%-100%TCE
----99%--100%-28%-PCE
-----100%---Methylenechloride
--97%--77%---36%-1,1-DCE
46%-91%--43%-84%--5%1,1-DCA
-99%---92%-100%-93%-50%-1,1,1-TCA
16'20'20'22'20'20'8'19'Depth ( feet-bgs)
H1K-39H1K-38H1K-36H1K-35H1K-34H1K-31H1K-31H1K-03Soil Boring
11
October 200521
Mass Reduction Summary
Ø Total Mass Reduction before & after studyØSoil mass
ØDissolved massØSorbed mass
BLUE/Gray - indicated INCREASE in concentration
RED/Yellow - indicates DECREASE in concentration
Pounds destroyed
Percent Difference
Maximum 125 lbs 47 lbs 78 62%Most Likely 61 lbs 47 lbs 14 23%Minimum 42 lbs 35 lbs 7 16%
Pre-Injection(Baseline)
Post-Injection (after Round 11)
October 200522
How much was it?
Ø Total Cost to Implement: $260K (2004)• Iron injection costs: $112K • Nanoscale iron: $37K (late 2003) *
• Today this cost would have been $5 to 14K• Monitoring costs: $111K
Ø Comparable to other technologies today…• Nanoscale iron: $185K (2005) • Chemical Oxidation: $145K• Bioremediation $ 150K - $175K • Excavation: $385K – $485K
* Pound per pound is not a good comparison
12
October 200523
Summary
Ø Data suggests favorable results
• Significant TCE & 1,1,1-TCA reductions across the site
• Generation of daughter products • cis-1,2 DCE, 1,1-DCE, 1,1-DCA • very little VC
• Mass destruction evident • Good mass balance in some wells• Ethene & ethene conentrations increased up to 2 order (770%)• Acetylene and light hydrocarbons increased up to 2 order
• Longevity of iron: 6 to 9 months
October 200524
Summary (cont.)
Ø Data suggests favorable results (cont.)
• Plume extent was reduced (MW-33 & MW-36)• At or below GCTLs levels in MW-39 (downgradient well)
• Reduced mass flux from source
Ø Concentrations in the ‘core’ returned (expected)• Elevated concentations returned in source wells
(MW-08, MW-32, MW-37)
Ø Mass reduced between 16 and 63 %• We met the 40-50% reduction goal (regulators)• To be included in the ROD for site
Ø Further reductions could have been achieved (not needed to meet project goals)
13
October 200525
Is this the Silver Bullet ?
Ø It works…but not inall cases.
– Quick…Not much to do (no nutrients, no pH issues)
– Good for small sources…not for very large ones– Bioremediation may work better in some
environments– An emerging science that is making strides– Treatment trains and ‘combinations’
Tetra Tech NUS, Inc.
October 200526
Thanks for attending
Keith Henn, PG
Phone: 412-921-8146
Email: [email protected]