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Lessons Learned on Various In-Situ and Ex-Situ PFAS Treatment TechnologiesJustin Gal, PEAssociate Engineer
Great Lakes Environmental Remediation& Redevelopment ConferenceOctober 16-18, 2019
Overview
Great Lakes Environmental Remediation & Redevelopment Conference 2019
1. Remediation State of the Practice• Soil• Water (surface water, groundwater, drinking water)
2. Developing Alternatives For Treatment and Wood Updates• Soil and water treatment• Destruction
2 A presentation by Wood.
Remediation State of the Practice
3
Commercially available soil remediation options
Great Lakes Environmental Remediation & Redevelopment Conference 2019
• Excavation and On or Offsite Encapsulation - Proven– Effective but expensive, landfill disposal options limited by regulation
• Incineration – Proven, but limited facilities– Very expensive, generally used on low volumes at high
concentrations• Stabilization – Limited full-scale applications
– RemBindTM
• Powdered reagent – Activated carbon, organic matter, and aluminum hydroxide
• Added at ratio of 1-10% by weight, has shown >98.5% reduction in leaching
– MatCARETM
• Modified clay adsorbent• pH, clay content and organic content influence PFOS release from
soil
4 A presentation by Wood.
Commercially available groundwater remediation options
Great Lakes Environmental Remediation & Redevelopment Conference 2019
Most proven options require pump and treat• Granular Activated Carbon (GAC)
– Most ubiquitously used for water• Ion Exchange
– A potentially cost-effective alternative to GAC• Reverse Osmosis
– Effective for a wide variety of PFAS, up to 90% efficient
– Reject water must be treated separately• Nanofiltration – less proven
– Effective removal of PFOS when calcium is present
• Foam Fractionation
5 A presentation by Wood.
Alternatives and Innovative Technologies
6
Developing treatment and destruction options
Great Lakes Environmental Remediation & Redevelopment Conference 2019
• Soil - mobilization, recovery and destruction– In-situ or ex-situ thermal desorption coupled with VES– In-situ liquid carbon
• Groundwater– Treatment
o Non-regenerable ion exchange resinso Ozone fractionationo In-situ carbon and biocharo Regenerable IX resin
– Destructiono Sonificationo Electrochemicalo Plasma
7 A presentation by Wood.
In-Situ Carbon
8
Alpena Hide and Leather Case Study –BioChar Injection and Soil Mixing Pilots at a Former Tannery
Case study
• Site setting/history• Conceptual site model• Brief description of pilot tests• Performance metrics
Great Lakes Environmental Remediation & Redevelopment Conference 20199 A presentation by Wood.
Conceptual site model
Great Lakes Environmental Remediation & Redevelopment Conference 201910 A presentation by Wood.
Conceptual site model
Great Lakes Environmental Remediation & Redevelopment Conference 2019
Non-PFAS Contaminants PFAS in Soil PFAS in Groundwater
Arsenic in Soil
Former Bulk Fuel Area
2017 Hide Removal
Injection
Soil Mixing
Injection
Soil Mixing
11 A presentation by Wood.
BAM pilot tests
EW-2 (~7.5 ft)
PZ-1 (~4ft)MW-5 (~9ft)
Utility Corridor
BAM-UltraTM Injections:• Vacuum truck extraction to enhance injections• Injection pressures of 40 – 100 psi• Bottom up injection (2-ft. lifts, 2-10 ft. bgs)• 100 gallons of 12.4% BAM-UltraTM solution
injected at 46 intervals/locations (5,300 pounds)• Variable loading rates based on ROIs
Soil Mixing Area
(10’x10’x8’)
BAM-XTM Soil Mixing:• Excavator bucket mixing• Mixed from surface to 8 ft. bgs (included
vadose zone application)• 1,600 pounds of BAM-XTM• 1.5% loading rate by mass• Mixed in place – no waste generated
Great Lakes Environmental Remediation & Redevelopment Conference 201912 A presentation by Wood.
Pilot test - soil results
Test Control Injection Area Soil Mixing
SPLP 122 – 112 74.4 (39%) 36.3 (68%)
TCLP 707 68.4 (90%) 35.7 (95%)
Leachate results in ng/L (percent reduction)
PilotPilot)
Great Lakes Environmental Remediation & Redevelopment Conference 201913 A presentation by Wood.
PFOS in soil at 4 – 5 feet below ground surface
• PZ-2R; Soil Mixing Area (~1.5% Loading Rate)
Soil mixing pilot test – groundwater results
Great Lakes Environmental Remediation & Redevelopment Conference 2019
PFAS Percent Reduction
PFBA -13.0PFBS 77.5
PFHxA 84.2PFHxS 94.26:2FTS 97.7PFOA 94.7PFOS 97.5
T-PFAS 88.6
• Hydraulic ConductivityPre-Test = 11 ft./dayPost Test = 0.9 ft./day
14 A presentation by Wood.
Injection pilot test - groundwater results
15
• MW-5; 9-ft Injection Array (~0.4% Loading Rate) PFAS Percent Reduction
PFBA 28.2PFBS 82.9
PFHxA 67.7PFHxS 71.86:2FTS 77.3PFOA 66.6PFOS 73.2
T-PFAS 70.5
• Hydraulic ConductivityPre-Test = 3.4 ft/dayPost Test = 7.5 ft/day
Ex-Situ Regenerable Ion Exchange Resin
16
Former Pease Air Force Base Case Study –Regenerable Ion Exchange Resin System
Case study
• Site setting• Project development• Full-scale implementation• Start-up and operation• Performance to date
Great Lakes Environmental Remediation & Redevelopment Conference 201917 A presentation by Wood.
• PFOS and PFOA first identified in 2013• Drinking water impacts confirmed in 2014• Base-wide investigations started• Interim actions initiated
Site setting
Great Lakes Environmental Remediation & Redevelopment Conference 201918 A presentation by Wood.
• Bench-scale testing identified an IX resin for PFAS removal that could be regenerated
• Wood contracted by the Air Force to perform pilot-scale testing of ECT2’s regenerable IX resin and coal-based GAC
• After 6-months of testing and five loading cycles
– IX resin substantially more effective at PFAS removal
– IX successfully regenerated
Project development – 2015 bench/pilot testing
19 Great Lakes Environmental Remediation & Redevelopment Conference 2019A presentation by Wood.
Full-scale implementation - design
Great Lakes Environmental Remediation & Redevelopment Conference 2019
Resin for PFASsBag Filters
10µ
Effluent Tank
Extraction Wells
Injection Trenches
Regeneration
Distillation
Regenerant Recovery
PFAS Waste
GAC for Organic Material
Bag Filters1µ
20
• Extraction design: 110 gpm• Treatment capacity: 200 gpm
A presentation by Wood.
Full-scale implementation - construction
Add caption directly on to solid colour parts of image
Great Lakes Environmental Remediation & Redevelopment Conference 201921 A presentation by Wood.
Full-scale implementation – treatment process
Great Lakes Environmental Remediation & Redevelopment Conference 2019
Pretreatment bag filters & GAC IX resin vessel skid IX resin polish vessels
22 A presentation by Wood.
Full-scale implementation –regeneration process
Great Lakes Environmental Remediation & Redevelopment Conference 2019
Regeneration skid Distiller Still bottoms and superloader
23 A presentation by Wood.
Start-up and operations
Great Lakes Environmental Remediation & Redevelopment Conference 2019
0.0
10.0
20.0
30.0
40.0
50.0
60.0
4/10/2018 5/10/2018 6/9/2018 7/9/2018 8/8/2018 9/7/2018 10/7/2018 11/6/2018 12/6/2018 1/5/2019 2/4/2019 3/6/2019 4/5/2019 5/5/2019
PFO
S +
PFO
A Co
ncen
tratio
n (u
g/L)
PFOS + PFOA Concentration through Treatment Train
Influent Concentration
Post GAC Concentration
Effluent Concentration
24 A presentation by Wood.
Start-up and operations - regeneration
Great Lakes Environmental Remediation & Redevelopment Conference 2019
Distiller Plant Influent
Still BottomsSpent Regenerant
Recovered Regenerant
Distillate Purifiers 1 & 2
Superloaders 1, 2 & 3
Sample Location PFOS (µg/L) PFOA (µg/L)
P-7200 Effluent - Regenerant Recovery Pump (Distiller Influent) 25 16Superloader 1 inlet (Still Bottoms) 540 220Post Superloader 1 0.19 0.010 UPost Superloader 2 0.12 0.010 UPost Superloader 3 0.086 0.010 UT-7420 Influent -Distallate Purifier 0.50 2.9T-7420 Effluent - Distillate Purifier #1 0.015 U 1.1T 7430 Effluent - Distillate Purifier #2 0.015 U 0.010 U
25 A presentation by Wood.
Destruction Technology
26
Wood - ongoing research and development
27 Great Lakes Environmental Remediation & Redevelopment Conference 2019
Awarded: “Removal and Destruction of PFAS and Co-Contaminants from Groundwater”
Environmental Security Technology Certification Program(ESTCP) U.S. DoD Technology Demonstration and Validation
Strategic Environmental Research and Development Program(SERDP) U.S. DoD Basic and Applied Research Program
Awarded: “Combined In-Situ/Ex-Situ Treatment Train for Remediation of PFAS Contaminated Groundwater”
Research Team:
A presentation by Wood.
Ongoing R&D – PFAS destruction via PLASMA
28 Great Lakes Environmental Remediation & Redevelopment Conference 2019
• Work presented by Clarkson University at Battelle Remediation Conference, May 2018.• Enhanced contact, low energy plasma reactor for two applications
- Treatment of investigation derived waste – low C aqueous solutions- Treatment of still bottom waste from regenerable IX – high C brine solution
• Technology demonstrated for IDW (discussed in the following slides)• Technology under development for still bottoms – two R&D projects starting now for
SERDP and ESTCP
Prototype Plasma Reactor for high C PFAS
Inventors: Mededovic and Holsen, Clarkson University
A presentation by Wood.
On-going R&D – PLASMA for PFAS destruction
29 Great Lakes Environmental Remediation & Redevelopment Conference 2019
• Plasma is an ionized gas consisting of a quasi-neutral mixture of neutral species, positive ions, negative ions, and electrons.
• Electrical discharge plasma formed directly in or above water makes use of OH radicals to oxidize and aqueous electrons to chemically reduce organic and inorganic compounds.
• Benefits of plasma-based water treatment:- Physical effects such as generation of ultraviolet-range radiation (UV), shockwaves capable of inducing
cavitation, and high temperatures capable of thermally decomposing molecules.- No chemical additives are required.- Wide variety of reactive chemical species (OH, eaq–, e–, O, H, H2O2, O2, HO2).
Pictures: Plasma Research Laboratory, Clarkson University
A presentation by Wood.
Plasma formation
30 Great Lakes Environmental Remediation & Redevelopment Conference 2019
Plasma in argon gas contacting water
METAL ELECTRODE
PLASMA INTERIOR
PLASMA-LIQUID BOUNDARY BULK LIQUID
OH, H, O
Sg
H
OHO
HO2
OH+Sl→products
~ 2 mm
PLASMA INTERFACE
e-
e-
H2O
Sl
H2O2
O2
H2
H+Sl→products
HO2+Sl→products
pyrolysisoxidation
UV
UV
UV
Sl =liquid solute Sg =gas solute
Courtesy of: Plasma Research Laboratory, Clarkson University
A presentation by Wood.
• Emerging as a viable technology – Proven field demonstration (high C still bottom PFAS
treated to ND)– Study results expected November 2019.
• Potentially applicable for:- Destruction of regenerant waste- IDW destruction- Not for continuous flow at this time
• More efficient and is relatively unaffected by the presence of co-contaminants.
• Mechanisms of PFAS destruction involves electrons and plasma (argon) ions.
• Market availability next step (mobile unit available)
Plasma summary
31 Great Lakes Environmental Remediation & Redevelopment Conference 2019
Courtesy of: Plasma Research Laboratory, Clarkson University
A presentation by Wood.
Potential no-waste solution
Treatment of high C still bottom waste
Lessons Learned
32
Lessons Learned• In-situ Carbon
– Biochar effectively reduced PFAS in groundwater– Biochar has less sorption of short chain carboxylic acids– Soil ion exchange capacity may have as much or more effect on PFAS sorption than fraction of
organic carbon– Soil mixing biochar had favorable results when evaluating with long term leaching test
• Ex-situ Regenerable IX Resin – Biggest challenge was iron fouling at front end of plant– GAC can be a workhorse– Fire protection can drive project costs and logistics for regeneration technology
• Plasma Destruction– No commercially available onsite destruction technologies– Developing treatment technologies show promise for greater removal capacity and potential
onsite application.
Great Lakes Environmental Remediation & Redevelopment Conference 201933 A presentation by Wood.
woodplc.com
Questions?
Thank you!For more information:
Justin Gal, PEAssociate Engineer
34
Thank you to Collaborators: David Woodward - Wood Nathan Hagelin - Wood
Rob Singer – WoodLen Mankowski - Wood
References
Great Lakes Environmental Remediation & Redevelopment Conference 2019
1. http://www.cdc.gov/healthcommunication/risks/index.html2. http://www.who.int/risk-communication/en/3. http://www.npr.org/sections/thetwo-way/2016/08/09/489369852/federal-
data-shows-firefighting-chemicals-in-u-s-drinking-water-sources4. https://papers.ssrn.com/sol3/papers.cfm?abstract_id=9883425. https://emergency.cdc.gov/cerc/resources/templates-tools.asp
35 A presentation by Wood.
Injection pilot test - groundwater results• PZ-1; 4-ft. Injection Array (~1% Loading Rate) PFAS Percent
ReductionPFBA 50.6PFBS 85.6
PFHxA 83.7PFHxS 92.46:2FTS 91.6PFOA 89.7PFOS 85.2
T-PFAS 88.3
• Hydraulic ConductivityPre-Test = 11 ft./dayPost Test = 8.0 ft./day
Great Lakes Environmental Remediation & Redevelopment Conference 201936 A presentation by Wood.
Injection pilot test - groundwater results
37
• EW-2; 7.5-ft Injection Array (~0.5% Loading Rate) PFAS Percent Reduction
PFBA -35.9PFBS 82.9
PFHxA 43.6PFHxS 88.56:2FTS 83.6PFOA 86.5PFOS 84.4
T-PFAS 82.4
Camp Grayling Case Study –Colloidal Activated Carbon in a Low Centration PCE Plume
Case study
• Site setting• Conceptual site model (injection area)• Brief description of pilot test• Performance metrics/mechanisms
Great Lakes Environmental Remediation & Redevelopment Conference 201938 A presentation by Wood.
Conceptual site model
Great Lakes Environmental Remediation & Redevelopment Conference 2019
• Former fire training area• Bulk fuel area
- Pump and treat system in place- Previous hydrogen release compound
(HRC) injections• Compounds in groundwater
- Historically SVOCs- Low level PCE (<10 ug/L)
• PFAS detected 2016- T-PFAS – 228 ng/L- PFOS – 110 ng/L- PFOA – 6 ng/L
39 A presentation by Wood.
• Shallow groundwater- Shallow Groundwater- Aquifer primarily sand- Depth to water: 14-15 feet- Depth to Clay: 27 feet
2018 PlumeStopTM injection pilot• PlumeStopTM injected October 2018 • Nine locations on 5-foot centers.• 2400 lbs. ea. of PlumeStopTM &
PlumeStop StoutTM (8-10,000 mg/L; ~ 750-1,000 gallons/pt)
• Bottom-up application (1-ft. to 3-ft. lifts; 14-26 ft. bgs)
• Injection pressures/flow rates up to 90 psi at 8 gpm
Great Lakes Environmental Remediation & Redevelopment Conference 201940 A presentation by Wood.
Camp Grayling Airfield – soil results• Physical testing:
- foc increased slightly- No significant change in CEC- No apparent correlation of CEC
to foc
- Pre-/post-injection slug test results relatively unchanged (Remains Fast!)
y = -9.52x + 11.22R² = 0.11
89
10111213
0 0.04 0.08 0.12 0.16
CEC
(med
/100
g)
foc (%)
0.00.20.40.60.81.0
0 1 2 3 4 5 6 7 8 9D
ispl
acem
ent (
%)
Elapsed Time (seconds)
Normalized Displacement over Time at MW-29c
March 2019
September 2018
Great Lakes Environmental Remediation & Redevelopment Conference 201941 A presentation by Wood.
• October 2018 (4 weeks)- No PFAS detected (shallow and deep
downgradient wells)- PCE = 1.22 ug/L (shallow)- PlumeStop™ spreading
OCTOBER 2018 Analytical Results (PFOS and PCE)
• March 2019 (~ 6 months)- PFOS = 9.6 ng/L in shallow
downgradient well (~50 ft.)- PCE detected in shallow wells at 25 and
50 ft. downgradient- PlumeStop™ - no further downgradient
expression
Time series results• Baseline
- PFOS = 70/40 ng/L- PFHxS = 60/50 ng/L- PFPeA = 10 ng/L (deep)- PCE = 8.28/3.12 ug/L
PFO
S Co
ncen
tratio
n (n
g/L)
PCE
Conc
entra
tion
(ug/
L)
Dept
h (fe
et)
Great Lakes Environmental Remediation & Redevelopment Conference 201942 A presentation by Wood.
Start-up and operations
Great Lakes Environmental Remediation & Redevelopment Conference 2019
0.0
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40.0
60.0
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4/10/2018 5/30/2018 7/19/2018 9/7/2018 10/27/2018 12/16/2018 2/4/2019 3/26/2019 5/15/2019
PFAS
Con
cent
ratio
n (µ
g/L)
Total Concentration of 13 PFAS Analyzed
Influent CombinedPost GAC CombinedEffluent Combined
43 A presentation by Wood.
Start-up and operations
Great Lakes Environmental Remediation & Redevelopment Conference 2019
0
500
1000
1500
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4000
0
5
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4/10/2018 5/10/2018 6/9/2018 7/9/2018 8/8/2018 9/7/2018 10/7/2018 11/6/2018 12/6/2018 1/5/2019 2/4/2019 3/6/2019 4/5/2019 5/5/2019
Tota
l Cum
ulat
ive P
FOS+
PFO
A Re
mov
al (g
ram
s)
Aver
age
Daily
PFO
S+PF
OA
Rem
oval
(gra
ms)
Site 8 Mass RemovalPFOS+PFOA Daily Mass RemovalPease 13 Daily Mass RemovalPFOS+PFOA Cumulative Mass RemovalPease 13 Cumulative Mass Removal
44 A presentation by Wood.
• Complete ongoing column studies• Refine media selection criteria• Operate/optimize non-regenerable IX
system• Continue site-specific evaluations• Optimize plasma destruction on high C still
bottoms• Complete SERDP and ESTCP projects
Next steps
45 Great Lakes Environmental Remediation & Redevelopment Conference 2019
Potential no-waste solution
Treatment of high C still bottom waste
A presentation by Wood.
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