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APRIL 2020 NEXT
IAN ROSS, Ph.D. ARCADIS UKGLOBAL PFAS LEAD
PER- & POLYFLUOROALKYL SUBSTANCES (PFASs) Big Picture, Challenges and Solutions
THE EMERGING ISSUE
© Arcadis 2016
Safety Moment: Foam “Disposal”
2
© Arcadis 2016 3
Property of Arcadis, all rights reserved
• PFAS News
• PFAS Chemistry, Characteristics and Analysis
• Widespread Uses
• Regulatory trends
• Firefighting Foams -Transition
• PFAS Behaviour - Fate and Transport
• Long Range Transport - Background
• PFAS point source risk management via CSMs
• Evolving treatment / Remediation strategies
• Summary
Overview
A CHANGING WORLD
In the News
2014-2018
© Arcadis 2016Detections of PFAS in drinking water has caused spiraling regulatory concern
PFAS News
© Arcadis 2016
August 14, 2020 6
Detected in ~ 2% of large public water supplies
USEPA UMCR 3, May 2016
PFASs in US Public Water Supplies
© Arcadis 2016
http://www.nytimes.com/2016/01/10/magazine/the-lawyer-who-
became-duponts-worst-nightmare.html?_r=0
© Arcadis 2016 8/14/2020 8
PFAS management requires pragmatism..
https://www.dutchnews.nl/news/2019/10/builders-pollution-protest-breaks-up-after-diggers-dump-earth-on-the-malieveld/
https://nltimes.nl/2019/10/30/construction-vehicles-heading-hague-protest-traffic-piling
https://www.dutchnews.nl/news/2019/10/ministers-aim-to-relax-pfas-
pollution-rules-after-new-limit-halts-earth-moving-work/
PFASs PROPERTIES AND CHEMISTRY
© Arcadis 2016
Specific Characteristics of PFASs
• MobilityPFASs tend to be very mobile in the environment as they are soluble in water (unlike most other POPs).
• Extreme PersistencePFASs show no sign of biodegradation and have been termed “forever chemicals”
• SurfactantsAmphiphilic PFASs stick on surfaces / interfaces when at higher concentrations
• BioaccumulationPFASs bioaccumulate and biomagnify via interaction with proteins (not fats like other POPs)Long Chain PFASs concentrate humans via renal reabsorption, so we fail to excrete them, whilst monkeys, mice and rats etc. can excrete at much faster rates
• ToxicityThere are very low (~70 ng/L) and diminishing regulatory acceptance criteria (drinking water standards) as more is known about the toxicity of specific PFASs
August 14, 2020 10
Property of Arcadis, all rights reserved
© Arcadis 2016 August 14, 2020 11
PFAAs totally resist biodegradation – are ultra-persistent
• Perfluoroalkyl acids (PFAAs) previously termed
Perfluorinated Compounds (PFCs) generally are
the and include:
• Perfluoralkyl carboxylates (PFCAs) e.g. PFOA
• Perfluoroalkyl sulfonates (PFSAs) e.g. PFOS
• Perfluoroalkyl phosphinic acids (PFPiS);
perfluoroalkyl phosphonic acids (PFPAs)
• Perfluoroalkyl ethers e.g. GenX
• There are many PFAAs with differing chain
lengths (generally C1-C18)
Perfluoroalkyl Acids (PFAAs)
Property of Arcadis, all rights reserved
© Arcadis 2016
Polyfluorinated Compounds -Precursors
• Thousands of polyfluorinated precursors to PFAAs have been commercially synthesized for bulk products
• The common feature of the precursors is that they will biotransform to make PFAA’s as persistent “dead end” daughter products
• PFAS do not biodegrade i.e. mineralise
• Some precursors are fluorotelomers
• Some are cationic (positively charged) or zwitterionic (mixed charges) –this influences their fate and transport in the environment
• Cationic / zwitterionic PFAS tend to be less mobile than anionic PFAAs and so can potentially be retained longer in “source zones”
• Environmental fate and transport will be complex as PFAS comprise multiple chain lengths and charges
PFOA
Property of Arcadis, all rights reserved
© Arcadis 2016
Poly- and Perfluoroalkyl Substances (PFASs) (~5,000 manufactured compounds)
Perfluorinated Compounds(PFCs)
or Perfluoroalkyl Acids (PFAAs)
~25 common individual compounds, terminal
daughters i.e. “forever chemicals”
e.g. PFOS, PFOA, PFHxS, PFBA, PFHxA
Polyfluorinated
“Precursors” -Proprietary
PFASs
Thousands of individual parent
compounds, sharing common
daughters e.g. 6:2 FTS, 5:3 acid
Environmental / Higher Organism Biotransformation
More Commonly Regulated
Property of Arcadis, all rights reserved
© Arcadis 2016
Perfluoroalkyl group –confers extreme persistence
PFOA
PFOS
PFHxS
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© Arcadis 2016
Aerobic Biotransformation Funnel: Conversion of Polyfluorinated Precursors to PFAAs
August 14, 2020 15
ANALYTICAL TOOLS
© Arcadis 2016
Analysis by LCMSMS via EPA Method 537 or similar
Conventional analysis will not reflect total PFAS mass
• US EPA Method 537: Analysis for selected PFAS in drinking water
• 12 PFAAs and 2 Precursors:
– PFHxA, PFHpA, PFOA, PFNA, PFDA, PFUA, PFDoA, PFTrA, PFTeA
– PFBS, PFHxS, PFOS
– N-EtFOSAA, N-MeFOSAA
• EPA 24
– PFTeDA, PFTrDA, PFDoA, PFUdA, PFDA, PFNA, PFOA, PFHpA, PFHxA, PFPeA, PFBA
– PFDS, PFNS, PFOS, PFHpS, PFHxSK, PFPeS, PFBS
– FOSA, 8:2FTS, 6:2FTS, 4:2FTS, N-EtFOSAA, N-MeFOSAA
• Method 537 has been adapted with more analytes to other media
• Up to 65 individual analytes (laboratory dependent)
• Groundwater with PFAS LODs ranging as low as 0.09 ng/L
• Availability of standards and other factors limit the number of PFAS that can be measured with a single method
• Thousands of precursors and their transient metabolites makes synthesis of a comprehensive set of standards unrealistic
Property of Arcadis, all rights reserved
© Arcadis 2016
Other PFAS Analytical Methods
MethodDemonstrated
Matrices
PFAS
Specific?
Total Oxidizable Precursor (TOP)
Assay
Aqueous, Soil, Human
Blood, Commercial
products
Yes
Extractable Organofluorine and
Ion Chromatography
Aqueous, Human
BloodNo
Particle Induced Gamma
Emission (PIGE) SpectroscopyCommercial products No
High Resolution Mass
SpectrometryAqueous, Solids Yes*
1806 February 2020
Total Organofluorine
Methods
© Arcadis 2016
Digest AFFF precursors and measure the hidden mass: TOP Assay
Microbes slowly make simpler PFAA’s (e.g. PFOS / PFOA) from PFAS (PFAA precursors) over 20+ years
Need to determine precursor concentrations as they will form PFAAs
Too many PFAS compounds and precursors –so very expensive analysis
Oxidative digest stoichiometrically converts PFAA precursors to PFAA’s
TOP assay indirectly measures total precursors as a result of increased PFAAs formed after oxidation vs before.
Property of Arcadis, all rights reserved
Analytical tools fail to measure the hidden PFAS precursor mass, the TOP assay solves this
© Arcadis 2016
0
5
10
15
20
ECF,2001
FT 1,2005
FT 2,2002
FT 3,2009
FT 4,2003
Co
nce
ntr
atio
n, g
/L
Pre-TOP Assay
PFOS
PFHpS
PFHxS
PFBS
PFNA
PFOA
PFHpA
PFHxA
PFPA
PFBA
Many formulations appear PFAS-free until precursors are revealed by TOP Assay
0
5
10
15
20
ECF,2001
FT 1,2005
FT 2,2002
FT 3,2009
FT 4,2003
Co
nce
ntr
atio
n, g
/L
Post-TOP Assay
PFOS
PFHpS
PFHxS
PFBS
PFNA
PFOA
PFHpA
PFHxA
PFPA
PFBA
FT: Fluorotelomer
ECF = Electrochemical Fluorination
Property of Arcadis, all rights reserved
TOP Assay Applied to AFFF Formulations
FT: Fluorotelomer
ECF = Electrochemical Fluorination
Houtz et al., 2013
PFASs Manufacturing and UsesWhere We Find Them and How They’ve Evolved
Property of Arcadis, all rights reserved
Firefighting Foams
Metal Plating
Textiles Electronics Photography Paper Coatings Paints Hydraulic Fluids
© Arcadis 2016
Manufacture of PFASs Three main methods of manufacture:
1. Electrochemical Fluorination
Used to manufacture branched and straight chain (~30% / 70%):
• perfluorosulfonates (e.g. PFOS, PFBS) and perfluorocarboxylates (e.g. PFOA)
• perfluoroalkylsulfonamides (e.g. FASAs, FASEs, FOSAAs, SAmPAP,
diSAmPAP, PFASaAm, PFASaAm)
2. Fluorotelomerisation
Used to manufacture even carbon numbered PFCA or PFPA/PFPiA precursors such as:
• Fluorotelomer alcohols (FTOHs) e.g. 6:2 FTOH,
• Fluorotelomer sulfonic acids (FTSs) e.g. 6:2 FTS, 8:2 FTS
• Fluorotelomer carboxylic acids (FTCAs) Fluorotelomer betaines (FTBs),
• Polyfluoroalkyl phosphates (PAPs) such as the diPAPs etc. etc.
3. Oligomerisation
Used to manufacture perfluoroalkylethers (PFECAs) and perfluoroalkyl ether sulfonate (PFESAs) such as: GenX hexafluoropropylene oxide dimer acid (HFPO-DA), HFPO-TA, ADONA
2206 February 2020
sulfonamido ethanol-based phosphate triester (tri-SAmPAP)
© Arcadis 2016
• Fluorosurfactant Firefighting foams for Class B (liquid hydrocarbon) fires e.g. Aqueous Film Forming Foams (AFFF), Film Forming Fluoroprotein Foams (FFFP)
• Electroplating mist suppressants
• Semiconductor manufacture
• Pesticides –Insecticides and Herbicides
• Aviation Hydraulic fluids
• Consumer Products
• Oil and water resistant finishes (paper, textiles, carpeting, cookware); Fast-food packagine
• Dyes, Polishes, Adhesives, Lubricants, Inks, Waxes
• Cleaning agents –detergents, carpet cleaners
• Shampoos and Hand creams
Multiple and Varied PFAS Uses
Property of Arcadis, all rights reserved
© Arcadis 2016
Potential Locations of PFAS Point Source Contamination
• Primary Manufacturing
• Secondary manufacturing / uses via application of PFASs to other products e.g.
o Fluoroplastics (e.g. PTFE)
o Paper Mills
o Carpet and Textile Manufacturing
o Metal Plating
o Paint Manufacturing
o Car wash/wax
o Leather tanneries
• Fire Training Sites
o Airports, Civil, Defence, Oil & Gas sites, Rail Yards, Power Plants
• Wastewater treatment plants –biosolid disposal
• Landfills
Property of Arcadis, all rights reserved
© Arcadis 2016
Next Generation PFASs
TOXICOLOGY / REGULATORY CLIMATE / PFAS DISTRIBUTION
Evolution of regulatory understanding globally and global distribution
Property of Arcadis, all rights reserved
© Arcadis 2016
Drinking Water
And Food
House dust
Indoor air
Outdoor air
Consumer products
• Fluoropolymers incl. side chain polymers
• Fluorosurfactants
• Performance chemicals
• Product residualsPrecursor
PFAA
Property of Arcadis, all rights reserved
Human Exposure to PFASs / Toxicity Long Chain Human
Bioaccumulation Half Life:
PFHxS 8.5 years
PFOS 4.2 years
PFOA 3.8 years
• PFAS bind to proteins (not to lipids / fats)
and are mainly detected in blood, liver and
kidneys
• PFOS: carcinogenity “suggestive” (US EPA,
2014). PFOA: “possibly carcinogenic”
(International Agency for Research on
Cancer, IARC, 2014)
• Study with 656 children demonstrated
elevated exposure to PFOS & PFOA are
associated with reduced humoral immune
response [1]
• Large epidemiological study of 69,000
persons found probable link between
elevated PFOA blood levels and the
following diseases: high cholesterol,
ulcerative colitis, thyroid disease, testicular
cancer, kidney cancer and preeclampsia –
C8 science panel [2]
[2] http://www.c8sciencepanel.org/
[1] Grandjean et al., JAMA 2012, 307, 391-397
© Arcadis 2016
0
200
400
600
800
1,000
1,200
1,400
1,600
EFSA,2008
EPA, 2009 2010 to2014
Denmark,2015
EPA, 2016(RfD)
RIVM,2016
Australia,2017
2018
TDI (ng/kg/body weight/d)
PFOS
PFOA
Source TDI PFOS
(ng/kg bw/day
TDI PFOA
(ng/kg bw/day)
EFSA, 2008 150 1500
EPA, 2009 80 190
Denmark, 2015 30 100
EPA, 2016 (RfD) 20 20
RIVM, 2016 - 12.5
Australia, 2017 20 160
EFSA, 2018 1.8 0.8
Tolerable Daily Intake (TDI)
Property of Arcadis, all rights reserved
© Arcadis 2016
Evolving Global Regulatory PFAS Values
29
Drinking, Surface and Ground Water (µg/l)
PFOS O=8
PFOA O=8
PFBS B=4
PFBA B=4
PFPeA/S Pe=5
PFHxA Hx=6
DENMARK(Drinking & Groundwater)
FEDERALGERMANY
(Drinking Water)
UK(Drinking Water)
AUSTRALIA(Drinking Water)
(0.09)
THE NETHERLANDS
US EPA(Drinking Water)
VERMONT(Drinking Water)
MINNESOTA(Drinking Water)
NEW JERSEY
CANADA(Drinking Water)
PFHxS Hx=6
PFHpA Hp=7
PFOSA O=8
PFNA N=9
PFDA D=10
Gen-X C6
COMPOUND REGULATED AND CHAIN LENGTH KEY
(0.07)
ITALY(Drinking Water)
(0.07)
TEXAS-Residential(Groundwater)
0.56
(1)
0.10.06
0.1
6
10
6
.030.5
0.5
(0.1)
1
0.60.2
15
30
0.20.2
0.2
0.02
.014.013
(0.02)
0.015.035
7
3
0.56
0.29
34
71
.093.093
0.56
0.290.37
.093
0.6
.53
.023ground
drinking
0.5
drinking
drinking.01ground
0.29
SWEDEN(Drinking Water)
(0.5)(0.5)
(0.5)(0.5)
(0.5)(0.5)
5
STATE OF BADEN-WÜRTTEMBERG
(Groundwater)
0.1
European Surface Waters (PFOS) 0.00065
Australian Surface Waters (PFOS) 0.00023
(0.07)
.013
MICHIGAN(Drinking Water)
(0.07).014
CONNECTICUT(Drinking Water)
(0.07)
ALASKA(Drinking Water)
(0.07)
NEW YORK(Drinking Water)
MICHIGAN(Groundwater
Surface Water Interface0.012 PFOS
0.01
0.01
CALIFORNIA(Drinking Water)
.014
0.0510.065
Property of Arcadis, all rights reserved
0.047
0.14
NORTHCAROLINAdrinking
0.10.1
“Race to the Bottom”
Queensland 0.25
(PFASs TOP Assay)
© Arcadis 2016
© Arcadis 2016
POPs Listed under Stockholm Convention
Original 12 are referred to as the Dirty Dozen:
• Aldrin, chlordane, DDT (some acceptable uses exempted), dieldrin, endrin, heptachlor, hexachlorobenzene, mirex, toxaphene, polychlorinated biphenyls (PCBs), polychlorinated dibenzo-p-dioxins and polychlorinated dibenzofurans (PCDD/PCDF)
Annex A: Listed for elimination (22 chemicals)
Annex B: Restricted (2 chemicals, DDT & PFOS)
Annex C: Avoid unintentional release (6 chemicals)
PFHxS and PFOA under consideration for classification
August 14, 2020 31
© Arcadis 2016
Persistent Organic Pollutants
If chemical are “PBT”, they can be restricted under European REACH and Stockholm Convention:
• Persistent:
• Half lives > 40 days in freshwater, >120 days in soil (REACH)
• Bioaccumulative:
• Bioconcentration factor/bioaccumulation factor in fish >2000 (REACH)
• Toxic
• Human: Chronic toxicity, carcinogenic/mutagenic/reprotoxic
• Ecological: No effect concentration (NOEC) <0.01 mg/L
August 14, 2020 32
PCBs
DDT
PFOS
© Arcadis 2016
Long Chain PFAS Replacements
Replacement shorter chain PFASs pose potential larger environmental threat
• Fluorotelomers are not biodegradable they form persistent PFAAs
• Concerns regarding Fluorotelomer precursors and (C6) replacements
• Multiple intermediate PFASs (~30 PFASs) evolved as fluorotelomersbiotransform
• Evidence of bioaccumulation of intermediates in rats (5:3 acid), invertebrates (6:2 FTS) and short chain PFAA bioaccumulation in edible portion of crops
• Fluorotelomer precursors described as being 10,000 X more toxic than PFAAs they biotransform into
• Limited information regarding toxicology of intermediates and PFAAs formed
• Short chain PFAAs, very water soluble, highly mobile, difficult to remove from wastewater, recirculate around water bodies, so more likely to be detected in drinking water
• Persistence and mobility (PMT, vPvM) criteria now being used by European regulators as bioaccumulation (PBT-based regulations) described to be marginally effective to protect drinking water supplies
33
https://www.umweltbundesamt.de/sites/default/file
s/medien/421/dokumente/01_uba_eisentrager_pm
t.pdf
© Arcadis 2016
August 14, 2020 34
Short chain replacement PFAS more mobile so more potential to impact drinking water
PBT Applicability?
• For drinking water quality, PBT-based regulations are only marginally
effective
• PBT aimed to protect food chain, not drinking water?
• In contrast, persistent and mobile organic compounds (PMOCs) are more of
a concern for water quality because, like PCBs, they can persist in the
environment, but they are not removed from water by sorption processes due
to their high polarity and thus excellent water solubility
• Therefore, they may end up in drinking water, posing a potential risk to
human health
• Umweltbundesamt (UBA) suggesting alternative assessment frameworks:
• PMT Persistent Mobile Toxic
• vPvM very Persistent and very Mobile as potential Substances of Very High Concern
© Arcadis 2016 35July 2016
Concerns over short chain PFAS - Overview
Persistent
• Based on read-across from long chain PFAS
• Long-range transport and findings in remote areas
Mobility and Exposure of Organisms
• Potential to contaminate drinking water resources
• Difficult to be removed from water
• Binding to proteins
• Non-negligible half-lives in organisms
• Enrichment in plants
Toxic
• No indications of ecotoxicity
• Toxicity in humans to be assessed
• Potential endocrine disruptor
Property of Arcadis, all rights reserved
Foams
36
© Arcadis 2016
• FP foams (fluoroprotein foams) used for hydrocarbon storage tank protection and marine applications.
• AFFF (aqueous film forming foams) used for aviation, marine and shallow spill fires and AR-AFFF (alcohol resistant aqueous film forming foams),
• FFFP foams (film forming fluoroprotein foams) used for aviation and shallow spill fires and AR-FFFP (alcohol resistant film forming fluoroprotein foams)
• PFAS foams contains both polyfluorinated and perfluorinated compounds
August 14, 2020 37
Class B Firefighting Foams
Timeline of AFFF addition to the DoD Qualified Products Listing (certified to MIL-F-24385 specifications).
© Arcadis 2016
PFAS Foams being Replaced
• C8 (PFOS and PFOA) generally phased-out
• C8 replaced with compounds with shorter (C6) perfluorinated chains
• C4, C6 PFAS are less bioaccumulative, but extremely persistent and more mobile in aquifer systems vs C8 - more difficult and expensive to treat in water.
• Solutions for characterizing all PFAS species important to cover current and future risks / liabilities
• Regulations addressing multiple chain length PFAS (long and short) are evolving globally – PFHxA ban coming
• Fluorine free (F3) foams contain no persistent pollutants
• F3 foams pass ICAO tests with highest ratings for extinguishment times and burn-back resistance and are widely available as replacements to AFFF
• Lastfire Independent Large Scale Storage Tank Test Program Results 2018: “It is not possible to state, for example, that all C6 foams demonstrate better performance than all FF foams and vice versa”
Property of Arcadis, all rights reserved
AFFF
FFFP
FP
AR-AFFF
AR-FFF
© Arcadis 2016
July 2016 39
Breakdown products of the C6 FT Foam: multiple intermediates to eventually form short-chain PFCAs
C6 Fluorotelomer Foam
Source: Weiner et.al. 2013
Stable Intermediate
Precursor
© Arcadis 2016
US Regulatory Heat Map
40
Proposition 65 (Safe Drinking Water and Toxic Enforcement Act)
Three routes of exposure: Occupational, Consumer, Environmental
Bounty hunter provision (¼ and ¾)
2018: Listing of PFOA as developmental toxicant
2019: Discharge prohibition comes into effect
Regulations Relevant to PFAS Containing Foam (AFFF, FFFP, FP) Usage
California
Kentucky
Washington
2018: Ban on training with PFAS foams
2019: Duty of manufacturers to inform users
2020: Ban on sale of PFAS firefighting foams
2024: Permitted exemptions expire (i.e. tank storage)
Updated March 12th 2020
Arizona Virginia
Georgia
2019: HB458 ruling restrict the use of firefighting foams containing PFAS for training and testing
while allowing continued use for real world fires
2020: Ban on uncontained release of PFAS foams, unless it’s an emergency
2019: Restrictions on the use of firefighting foams containing PFAS for
training and testing while allowing continued use for real world fires2019: Prohibiting discharge or other testing or training uses of PFAS-
containing class B firefighting foam carves out usage "required by law
or federal regulation"
https://chemicalwatch.com/78075/expert-focus-us-states-outpace-epa-on-pfas-firefighting-foam-laws#overlay-strip
https://chemicalwatch.com/83098/michigan-house-passes-bills-on-pfass-in-firefighting-foam
https://chemicalwatch.com/92626/wisconsin-to-restrict-pfas-containing-firefighting-foams
https://chemicalwatch.com/86978/new-york-state-to-restrict-firefighting-foams-containing-pfass#overlay-strip
Colorado
2019: Law prohibits the use of class B firefighting foam that
contains PFAS for training purposes, and violations may
result in imposition of a civil penalty
Limits the sale of PFAS firefighting foam, and requires
manufacturers to notify their customers of this law.
Addresses PPE by requiring PPE manufacturers to disclose
whether their product contains PFAS
Minnesota
2019: Law prohibits class B firefighting foam containing PFAS chemicals for testing or training, unless required by federal law, but excludes from
this ban use of AFFF in emergency firefighting and fire prevention activities
Any release of class B firefighting foam containing PFAS must be reported within 24 hours.
Prohibited PFAS-containing flame-retardants in residential products, like furniture, mattresses, textiles and window coverings
Also addresses products that contain organohalogen flame retardant compounds as a group
Michigan
2019: Bill HB 4390 would ban the use of PFAS-containing foam during firefighting training,
beginning on 31 December 2023. And until that date, firefighters would need to be
instructed in the proper use, handling and storage of the foams, as well as on containment
and proper disposal.
Bill HB 4391 outlines the "best health practices" for using, handling and storing the foam,
including decontamination of a firefighter’s body and equipment.
Bill HB 4389 would require that fire departments submit a written report to the State within
48 hours of using an AFFF
Wisconsin
2020: Law bans the use of firefighting foams with intentionally added per- and polyfluoroalkyl
substances (PFASs) for training purposes. The foams will be allowed for use in emergency
firefighting and testing purposes, although testing facilities must implement "appropriate containment,
treatment, and disposal or storage measures to prevent discharges of the foam to the environment."
New York
2019: Law bans the use of PFAS-containing class B firefighting foams for training
purposes, and will prohibit their manufacture, sale or distribution two years later. Certain
exemptions, such as when the products’ use is required by federal law, or to fight fires at
oil refineries or chemical plants.
© Arcadis 2016
Regulation of PFHxA• EU proposal to limit the use of PFHxA related substances
(precursors) – December 2019;
• Rationale:
• “Fulfils the P-criterion and vP-criterion”
• “Mobility and long range transport potential” and “unpredictable and irreversible adverse effects on the environment or human health over time”
• Exemptions (5 years) are in place for certain uses:
• Hard chrome plating;
• Photographic coatings;
• Firefighting foams – Emergency use only
• There is no exemption for testing (unless all releases contained) or training with fire fighting foams.
• Exemptions (12 year) are in place for Class B firefighting foams used to protect storage tanks with a surface area above 500m2
• Military users exempted – Requirement that during training foam contained and disposed of safely
• The EU considers the restriction practical as it is affordable, implementable, and manageable
© Arcadis 2016
www.lastfire.org.uk
Research Work – Rational Progression - more than 200 tests
Small scale
Simulated tank fire
Critical application rates
Spill fire
Critical application rates
Larger scale
“Real life” Application
NFPA rates
Phases have included
Different foams
Different nozzles
Different application methods
Different rates
Different fuels (including crude)
Different preburns
Fresh/Salt water
Longer flow
“Real life” Application
NFPA ratesSubsurface tests
Hybrid Medium
Expansion
Self expanding
foamVapour
suppression
Further obstructed spill
fire testing
© Arcadis 2016
Royal Danish Airforce in action using F3 foams
43
Performance of F3 Foams - Defence
“My experience is that fluorine free foam works flawlessly. We have used it in two major incidents, and we are using it for training purposes”
“When it comes to the extinguishing capability of the
fluorine free foam, there are, from my point of view, no
difference compared to the old AFFF foam containing
PFAS. It works exactly as good as the old stuff.”
“Put you self in the place of a crewmember trapped in a
fuselage engulfed in flames. Ask yourself a question;
would I trust the fluorine free foam? I would.”
https://www.linkedin.com/pulse/high-flow-fluorine-free-foam-lars-andersen/
Lars Andersen, Fire Chief, Royal Danish Airforce:
https://www.linkedin.com/pulse/how-fluorine-free-foam-does-work-practice-lars-andersen/
Experienced End User Perspective –F3 Foams work flawlessly
© Arcadis 2016 44
Use of F3 Foams – Oil & Gas
Oil & Gas Sector Complete Conversion to F3
Equinor (formerly Statoil) major Scandinavian
petrochemical company switched completely to
fluorine-free firefighting (F3) foam from 2013
for both its onshore and offshore (North Sea)
operations,
after having carried out extensive testing and due
diligence on alternatives to AFFF before changing
over.
HOCNF – The Harmonised Offshore Chemical Notification Format used to accredit F3 foams Equinor operates 42 fields on the Norwegian Continental
Shelf (NCS) representing 80% of all production on theNCS, producing 2.5 million barrels per day oil and gas,equivalent to 50% of total production for the North Seaincluding the Norwegian sector
© Arcadis 2016
GreenScreen CertifiedTM
Independent Certification of Environmental Profiles for Firefighting Foams
• Provision of a full product inventory from foam manufacturers to
Clean Product Action under a confidentiality agreement
• Clean Product Action reviews all relevant environmental and
human health data
• Data requirements vary by certification level and include :
• GreenScreen List TranslatorTM scores and GreenScreen
Benchmark scores
• Product-level acute aquatic toxicity data for fish, aquatic
invertebrates and algae
• Ingredient-level aquatic toxicity and fate data meet USEPA
Safer choice criteria (Master criteria or Direct Release criteria)
• Restricted ingredients:
• Organohalogens, PFASs, Siloxanes, Alkyl Phenols &
Alkylphenol Ethoxylates
• Three levels of certification: Bronze, Silver and Gold
PR
AC
TIC
ALI
TIES
OF
TRA
NSI
TIO
NIN
G T
O F
LUO
RIN
E FR
EE F
OA
M C
ASE
STU
DIE
S
46
NEXTPREVIOUS
Case Study: PFAS Rebound into F3 One year after changeout of hangar to F3 using a dual water flush:• PFAS residual up to 1.6 g/L in F3 foam lines;• Fire Water Supply remains impacted
Significant rebound of PFAS into F3 Foams after two water flushes
Sampling Locations
Sum
of P
FA
S T
op A
ssay
(ug/L
)
© Arcadis 2016
Case StudiesSystem Decontamination
Cleaning agent and TOP assay Required for Effective DecontaminationAugust 14, 2020 47
0
50,000
100,000
150,000
200,000
250,000
300,000
350,000
To
tal P
FA
S (
ng
/L)
Foam Tank Cleanout – TOP Assay
0
10,000
20,000
30,000
40,000
PFOS
PF
OS
Co
nce
ntr
atio
n (
ng
/L)
Sewer Decontamination Trial
Baseline Water
Cleaning Agent
Final Water
2 1,900 970 1,000
38,000
44
Control
1st H2O
Caustic
2nd H2O
CleaningAgent
3rd H2O
Pre-TOP
Post TOP
2,480
153,000
326,000
3,840 78 3,880
Sequential Sequential
© Arcadis 2016
Foam Disposal
• Fluorinated fire fighting foam comprise a complex waste
• Dispensed fluorinated foam and foam concentrates cannotbe treated using biological waste water treatment plants i.e.
– Municipal sewage treatment
– Publically operated treatment works (POTW)
• All fluorosurfactants / PFASs in foams are non-biodegradable, PFASs are extremely persistent
• Significant challenges and costs disposing of fluorinated fire fighting foams i.e. AFFF, FP, FFFP and their AR-variations
• Incineration of liquids containing PFASs problematic in U.S.
• Confirm that fluorine free foams100% biodegradable, so are significantly easier to dispose of via conventional biological treatment methods i.e. POTW, sewage treatment
PFAS are extremely persistent, some biotransform into others but none biodegrade
persistence = non-biodegradable
non-biodegradable = not treated biologically
© Arcadis 2016
Incineration
August 14, 2020 49
• 1,000 to 1,200 ºC (1,800 – 2,200 ºF) required to completely degrade PFOS
• Expensive and energy intensive options
• Hydrogen Fluoride management essential
• Lower temperature incineration of PFASs can produce toxic intermediates (e.g. perfluoroisobutylene) or potent greenhouse gases (CF4, C2F6 etc.)
• Cement kilns also being employed, for effective high temperature destruction with Ca(OH)2 to create CaF2
• Comprehensive analysis of all gaseous emissions required for any thermal treatment
https://toxnet.nlm.nih.gov/cgi-bin/sis/search/a?dbs+hsdb:@term+@DOCNO+7708
© Arcadis 2016
Evolving Foam Treatment Options
August 14, 2020 50
• Treatment trains required for complex wastes such as dispensed foam and concentrates
• Sonolysis using ultrasound proven at laboratory scale and being scaled up
• Ultrasound causes cavitation of bubbles with extremely high temperatures and plasma on the surfaces of the bubbles resulting in destruction of PFASs.
• Ultrasound trials progressing using AFFF foam concentrates
• Foam concentrate pretreatment prior to sonolysis essential
• Potential to receive samples of AFFF for testing
• Options to retain and store AFFF concentrates until more sustainable treatment technologies are commercially available
Fate and Transport
© Arcadis 2016
Transport Pathways
8/14/2020 52
© Arcadis 2016
Vapor Phase Transport -Mainly neutral precursors
Longer transport potential~20 days atmospheric lifetime (8:2 FtOH)
Atmospheric transformation of precursors to other PFAS by reaction with:NOx, OH•, O3, O2
Particle phase/ Aerosol transport –PFAAs and Precursors
Wet Deposition of Vapor-Phase PFAS
Dry Deposition of Particle –Associated
PFAS
Wet Deposition of Particle –Associated
PFAS
Shorter transport potential~3-5 days atmospheric lifetime (PM2.5)
PFAS Atmospheric Fate & Transport
PFOA associated with small particles (<0.14 um) and PFOS associated with larger particles (1.38 to 3.81 um) (A. Dreyer et al. Chemosphere 2015)
© Arcadis 2016 River Thames highest PFASs in Rivers July 2016 54
© Arcadis 2016
Groundwater
• PFCs detected in 26% of groundwater sites
• Detection even at “low risk” sites
Surface Water
• PFCs detected at 52% of surface water sites (drinking water abstractions)
• PFCs detected at 67% “high risk” sites
• The Environment Agency PFC monitoring (2008)
• Groundwater sampling
• Conducted at 219 sites in England and Wales (6.5% EA network)
• The majority of sites were in areas of potential sources eg. airfields
• “Low risk rural sites” comprised 5%
• Surface water sampling
• Drinking water abstractions (42 sites)
• “Higher risk sites” (39 sites) eg. effluents from sewage works
• Limits of detection were 0.1 ug/L so above the new US EPA standards at 0.07 ug/L
© Arcadis 2016
PFAS in European Surface Waters
July 2016 56
Property of Arcadis, all rights reserved
River PFOS (ng/l) Flow(m3/s)
Scheldt (Be, NL) 154 -
Seine (Fr) 97 80
Severn (UK) 238 33
Rhine (Ge) 32 1,170
Krka (Sl) 1,371 50
© Arcadis 2016
PFOS EQS Exceedances
8/14/2020 57
© Arcadis 2016
Subsurface Retardation of PFAS in Groundwater• Hydrophobic interaction
• Predominant sorption mechanism for long chain PFAS
• Organic rich soils retard movement of PFAS
• foc increases -> Kd increases
• Oil and other organics may also increase sorption
• Electrostatic effects
• Positively charged PFAS (i.e. some precursors) sorb to negatively charged minerals
• Anionic minerals (clays etc.) repel anionic PFASs
• Negatively charged PFAS sorb to positively charged minerals
• Under acidic pH, mineral surfaces tend to be more positively charge –promoting adsorption of PFAAs
• Electrostatic repulsion can decrease PFAS sorption
• High ionic strength dulls electrostatic repulsion; favoring adsorption
58
Subsurface Retardation of PFASs in Groundwater
Higgins & Luthy, 2006
Conceptual electrostatic effects
Conceptual repulsion
Property of Arcadis, all rights reserved
Li et al., 2018
© Arcadis 2016
0 5000 10000 15000 20000 25000 30000
5.0 - 5.5
4.0 - 4.5
3.5 - 4.0
3.0 - 3.5
2.0 - 2.5
1.0 - 1.5
0.0 -0.5
0 20000 40000 60000 80000 100000 120000
2.0-2.5mPOST TOP
2.0-2.5mPRE TOP
0.0-0.5mPOST TOP
0.0-0.5mPRE TOP
Vertical Soil Profiling with TOP Assay
PFBA PFPeA PFHxA PFHpA PFOA PFNA
PFOS
PFHxSPFHxS
PFOS
PFDS8:2 FTS 6:2 FTS
• Significantly more mass of amphiphilic PFASs in unsaturated zone vs saturated zone;
• Reduction in PFASs soil concentrations at groundwater level;• Precursors in ECF foams less mobile as cationic /
zwitterionic but biotransform to create PFHxS, PFOS,
PFPeS, PFBS not PFCAs• Soil extraction methods for PFASs targets anions so extraction of
cations/zwitterions likely gross underestimationAssessment methods for PFASs in soils evolving 06 February 2020 59
© Arcadis 2016 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1
Vertical Distribution of PFASs in Soils
0.01
0.1
1
10
100
1000
10000
Con
c.
(µg/k
g d
w)
Modified after Baduel et al. 2017
PFCAs (C4-10) PFSAs (C1-11) 6:2/8:2FTS
FASA (C3-8) 6:2
FTSAS
PFSaAm(C6/C8)
Vertical Distribution (fraction of the PFASs over 4 discrete depths)
0.5
1.0
1.5
2.0De
pth
(m
)
C4 C10 C1 C11 C3 C8
Property of Arcadis, all rights reserved
60August 14, 202006 February 2020 60
© Arcadis 2016
Increasing mobility of shorter perfluoroalkyl chain PFAS
C6 C4 C5 C3? C2?
C8 C7 C6 C4 C5 C3? C2?Hidden anionic mobile PFAA
precursors
Anionic precursor biotransformation
increases as aerobic conditions develop
Direction of groundwater flow
Anionic PFAA
dead end
daughters
0
0
C F S 08 17
0
00H3C 0
C 4H9
0
C8F17 S 0 0
0
00H3C 0
C 4H9
0
0
S 0C8F17
C F
0
0
S 08 17
0
0
C6F13
S 0
0
0
C8F17
0
0
S 0S 0 C8F17
0
0
S 0C8F17
0
S 0C8F17
0
0
S 0C6F13
0
C6F13
0
0
0
S 0S 0
0C6
F13
Source Zone - Hidden Cationic and Zwitterionic PrecursorsLess mobile as bound via ion exchange to negatively charged fine grain soils
(e.g. silts & clays). Precursor biotransformation is limited by the anaerobic redox
conditions created by the co-occuring hydrocarbons.F
N+
0
0H
0
00
C1H9
C F
H3C 0
0
0
S 08 17
0
0
S
N H
C 8F17
NH+
FF C
n
0
0 0H
NS
F
F C
F n0
0
H3C 00 C 4H9
0
0H
0
N+F
F
F C
F
C6F13
0
0
S 0 N
NNS
0 H
0
F
F C
F n
0
0-C5F11
0
H3C 0
0
00H3C 0
C 4H9
0 C4H9
0 0
C6F17 S 0
0
CH
CH
CH
CHCH
CH
CH
AFFF/FFFP/FP
CH 3
CH 3
CH 3
CH 3
CH 3
Hydrocarbon NAPL Short hydrocarbon plume
-300mV -200mVREDOX
ZONATION-100mV 0mV 100mV 200mV
C7C8
PFAS Source and Plume CSM
Property of Arcadis, all rights reserved
© Arcadis 2016
Long lasting sources of PFAAs
August 14, 2020 62
• The unsaturated zones continue to be a source of
PFASs to the groundwater after 18 years (FTA-1)
and 20 years (infiltration beds) of inactivity.
• Anoxic conditions may have allowed for the
observation of differential transport through the
elimination or reduction of in situ PFAA production
from precursors.
• Some precursors are quite mobile at this field site
• Results indicate that shorter chain length PFAAs are
more mobile than PFOS both vertically and
horizontally.
© Arcadis 2016
August 14, 2020 63
• There is a secondary source to the east but surficial soils have been replaced
• Prior aerobic bioremediation in western source / plume targeting hydrocarbons, in the existing source enabled biotransformation of PFAA precursors.
PFAA Generation from Precursors
Eastern source area:
• Simply looking for PFAAs and not employing the TOP
assay may obscure the actual potential for PFAS
contamination
Conclusion:
McGuire et al., 2014
Property of Arcadis, all rights reserved
>
Point Source Management:
© Arcadis 2016
Groundwater Risks to Receptors
AFFF / FFFP / FP
Fire training
Incident Response Source – Pathway – Receptor
High concentration, spill site,
route via groundwater to receptor
e.g. drinking water well
Diffuse
Ground level impacts and
ground/surface water
Landfill Leachate
Municipal / Domestic WWTP
Industry & Manufacturing
Agricultural Land
Commercial / Domestic Products
Metal Plating
Car Wash/Wax
ASTs –Fuel storage (FFFP / FP) Grasshopper effect
via widening of source zones
e.g. concentrated plume intercepts crop spray irrigation to make secondary wider source area for more dilute plume
?
?
?
© Arcadis 2020
Phase 1 Investigations & GIS Vulnerability Tool
66
• Phase 1 Investigations of site portfolios to enable risk ranking
• Facilitated using GIS
• ArcWeb GIS platform enables external metadata linking and analysis with widgets
• Data generated in tabular form – requires manual interpretation
© Arcadis 2016
Excessive Costs
Risk based approaches not adopted in Germany August 14, 2020 67
http://greensciencepolicy.org/wp-
content/uploads/2016/09/Rolland-Weber-PFOS-
PFAS-German-activities-Final.pdf
© Arcadis 2016
Channel Island AirportSite Setting and Drivers
Setting
• Densely populated island communities
• Surface water dominated drinking water supply
• Airport – topographical high point within water supply catchments
• Shallow water table (<0.5m bgl)
Source
• Fire fighting foam usage
Drivers
• To provide a sustainable solution which would protect drinking water sources and the wider environment in the short, medium and longer terms
August 14, 2020
68
© Arcadis 2016
Incidents & Foam Usage
11 locations were identified whereairport firefighting foam containingPFAS had been used7 of these areas were found to beimpacted with PFAS.4 locations were then prioritised andwere subject to further investigationsand remediation, including:
Fire Training AreaFire Tender IncidentFire Station Area1999 Crash Site
Interim Emergency ResponseMeasures
Sampling adjacent to fire stationrevealed elevated PFOSconcentrations entering drainageLocalised dewatering quicklyestablished to prevent ongoingmigration of PFOS
August 14, 2020
69
© Arcadis 2016
Fate & Transport Modelling – Site Specific Detailed Quantitative Risk Assessment
• Site Detailed quantitative risk assessment (DQRA) of the delineated PFOS soil and water impacts
• Modelling for alternative locations and likely volumes of PFOS impacted material that would be moved during any airport redevelopment works.
• Site specific model in order to model accurately the anticipated migration of the PFOS
August 14, 2020
70
© Arcadis 2016 August 14, 2020 71
© Arcadis 2016 August 14, 2020 72
Treatment and Restoration
Property of Arcadis, all rights reserved
© Arcadis 2016
Sta
ge o
f D
evelo
pm
en
t
Practicability
Ma
ture
Exp
eri
me
nta
l
Not Viable Feasible
*AOP/ARP: Advanced oxidation processes/advanced reduction processes
Flocculation/
Electrocoagulation
Activated Carbon
Sonolysis
Ion Exchange
Ozofractionation
Polymeric Adsorbents
Electrochemical Treatment
AOP/ARP*
Photolysis
RO/NF**
**RO/NF: Reverse Osmosis/NanofiltrationEnzymes
Adsorptive/Separation
Destruction
Incineration
In Situ Foam Fractionation
Property of Arcadis, all rights reserved
PFAS Treatment Technologies for Water
74
Optimization Research
Development Research
Plasma
Injected Activated Carbon
© Arcadis 2016
*AOP/ARP: Advanced oxidation processes/advanced reduction processes
Incineration
Soil Stabilization
Ex Situ Thermal
Soil Washing
Ball Milling
AOP/ARP*
Excavation
PFAS Treatment Technologies for Soil/Sediment
Property of Arcadis, all rights reserved
Sta
ge o
f D
evelo
pm
en
t
Practicability
Ma
ture
Exp
eri
me
nta
l
Not Viable Feasible75
Fixation/Separation
Destruction
Optimization Research
Development Research
© Arcadis 2016 August 14, 2020 76
ADSORPTION/
SEPARATIONFIXATION DESTRUCTION
Property of Arcadis, all rights reserved
© Arcadis 2016 August 14, 2020 77
ACTIVATED CARBON (GRANULAR OR POWDERED)Surface Water
GroundWater
Point Of Entry (POE)
Systems
• AC can effectively remove PFOA/PFOS from water (>90%); 7 to 15 empty bed contact time (EBCT).
• Reactivation viable, improves sustainability, reduce cost ~15%, may also improve removal performance.
Applicability:
Benefits:
• Manages low PFOA/PFOS concentrations; low flow rates.
• Well understood, community friendly, rapid deployment, “de facto IRM.”
• Effectiveness decreases as PFAA chain length decreases; questionable removal of precursors. May be managed with longer EBCT?
• Competition with natural organic materials (NOM)/total organic carbon (TOC).
• Perpetual for the foreseeable future until destructive technologies develop (focus on optimization).
Limitations:
Property of Arcadis, all rights reserved
© Arcadis 2016
78
• Green lines: lead vessel GAC replacement
• Orange line: lead and lag GAC replacement
• Shortest chain (PFBA) breaks through first; PFBA is not regulated currently, but may be subject to future regulation
• PFBA C/C0 >1; implies sorption/desorption or transformation?
• Routine O&M/GAC change outs controls contaminant breakthrough; large GAC vessel sizes and lower flow rate will extended GAC lifetime
Dickenson and Higgins, 2016 Property of Arcadis, all rights reserved
Activated Carbon (cont.)
© Arcadis 2016 79
Xiao et al., 2017 Property of Arcadis, all rights reserved
Activated Carbon Limitations
© Arcadis 2016
August 14, 2020 80
ANION/ION EXCHANGE
Zaggia et al 2016;
1 mg/L PFOA for 120 hr
• AIX can effectively remove PFAAs from water with effectiveness ranging from 10% to >90%.
• Reactivation methods available, though high throughputs may justify single use.
Applicability:
• Sensitive to site-specific geochemistry; methanol/brine reactivation may be required; comparative assessment of engineered resins challenged by inconsistent data reporting in the literature.
Limitations:
Benefits:
• Engineered resins (variable functional groups on the surface of polystyrene or polyacrylic resins) enable enhanced selectivity.
• Smaller equipment footprints, lower EBCT than AC (3 min versus 7 to 15 min).
• Recent field-test data suggests enhanced AC performance with AIX polish and demonstrated greater removal of PFHpA, PFNA, PFHxS, and PFBS.
Property of Arcadis, all rights reserved
© Arcadis 2016
Property of Arcadis, all rights reserved
81
Source: Edmiston 2019
Quaternary Amines
Polymers of Quaternary Amines
Perfluoroalkyl moiety (fluorophillicity)
Engineered adsorbents may
impart greater electrostatic affinity
and enable fluorophillic adsorption
Polymeric Adsorbents
“Scaffolding”
© Arcadis 2016
HRX Well® Description
The HRX Well* is a large-diameter horizontal well installed along the groundwater flowpath that is filled with treatment media for long-term in situ mass flux/discharge control
➢Passive in-situ treatment➢Many solid-phase reactive media options ➢Efficient use of reactive media➢Treatment train approach possible➢Not limited to high-permeability aquifers
➢Can be applied in relatively deep settings➢Limited above-ground footprint➢Minimal O&M➢No ongoing energy requirements➢Pumping can enhance treatment zone size
Impacted Groundwater
“Flow-
focusing”
*Patent US20120261125A1
Treated Groundwater
Treatment Media
Time
Co
nce
ntr
ation
© Arcadis 2016
Model-Calculated Treatment Zone:Active (Pumping) Operation
83
Active Operation: Flow = 3.90 ft3/day
© Arcadis 2016 August 14, 2020 84
ADSORPTION/
SEPARATIONFIXATION DESTRUCTION
Property of Arcadis, all rights reserved
© Arcadis 2016
Property of Arcadis, all rights reserved
ISS Reduce leachability
of PFASs to groundwater
Pragmatic alternative
due to cost of removal;
destruction concerns?
ISS does not
destroy/remove PFAS –
risk managed with long-
term GW monitoring
Soil Stabilization (ISS; Potentially with Solidification)
85
CSMs showing PFAS
shallow, proximal to
historical releases
© Arcadis 2016
0
2,000
4,000
6,000
8,000
10,000
5% PC Control 5% Modified Clayplus 5% PC
10% ModifiedClay plus 5% PC
5% AlOH/GACplus 10% PC
10% AlOH/GACplus 15% PC
To
tal P
FA
As
Po
st-
TO
P (
ng
/L)
Monitoring Event 1 - LEAF 1315 Interval T03 DPT-1
DPT-2
DPT-3
5% wt Reagent 1 5% PC
10% wt Reagent 1 5% PC
5% wt Reagent 2 10% PC
10% wt Reagent 2 15% PC
5% PC
Non Detect
Field-Scale Post Implementation Monitoring
Property of Arcadis, all rights reserved
Non Detect
86
© Arcadis 2016 August 14, 2020 87
ADSORPTION/
SEPARATIONFIXATION DESTRUCTION
Property of Arcadis, all rights reserved
© Arcadis 2016 Huang and Jaffe 2019
Biological Defluorination ofPFOA/PFOS
• 23% to 50% PFOA or PFOS reductions via enhanced or pure Acidimicrobium sp. strain A6 (either NH4
+ or H2 electron donors)
• Formation of acetate with sustained DOC mass balance, suggests synergistic A6 partial defluorination and heterotrophic species mineralization (enriched A6 cultures)
• PFOS may have more detrimental influence on A6 than PFOA
0
1
2
3
4
5
0 25 50 75 100
F (
in P
FA
S)
mM
time (d)
PFOA
PFBA
PFPeA
PFHxA
PFHpA
F-
Tot F
© Arcadis 2016
Electrochemical Degradation
August 14, 2020 89
• Electrochemical cells can degrade PFAS through direct electron transfer at the surface of the anode.
Applicability:
• Geochemical constituents may cause secondary concerns (i.e., chloride oxidized to perchlorate).
• Acidity around anode may facilitate PFOS sorption; needs further investigation. Confirmed effectiveness for sulfonates?
• Short chain PFAAs appear to be recalcitrant at low current density (<50 mA/cm2).
• Lowest demonstrate concentration >1,000 ppt
Limitations:
Benefits:
• Provides a feasible destruction mechanism for concentrated PFAS waste streams at low flow rate.
• PFAS degradation confirmed (fluorine mass balance); effective for both laboratory and real groundwater/wastewater.
• Less energy consumption than sonolysis.
0.1
1
10
100
1000
10000
0 4 8 12
[C] (m
g/L
)
Time (hr)
Cl- Cl2 ClO3- ClO4-
Gomez-Ruiz et al 2017
1
100
10,000
1,000,000
Influent 98% Power 99.7% Power
∑P
FA
S (
pp
t)
HAL = 70
1,625,000
4,22033,040
0.15 kW-hr/L
0.26 kW-hr/L
Property of Arcadis, all rights reserved
© Arcadis 2016
Sonolysis
August 14, 2020 90
• Ultrasound applied to water results in successive rarefaction/compression of microbubbles ultimately yielding cavitation with extremely high temperatures on the surfaces of the bubbles resulting in pyrolysis of PFAS.
Applicability:
Benefits:
• Can reliably destroy concentrated PFAS waste streams with literature supported fluoride mass balance.
• Opportunities to use green energy sources as technology develops (i.e., solar power).
• PFOA rate > PFOS rate. PFOS will require longer residence times and/or more energy. Effective below 10,000 ppt?
• Requires specialized equipment and skilled implementation.
• High energy consumption and low flow rates.
Limitations:
$1
$10
$100
$1,000
$10,000
$100,000
0.05 0.5 5 50 500
FLOW RATE (GPM)
ENERGY COST (USD)Assumes $0.12/kW-hr and 10 hr/d operation time
0.3 kW-hr/L
Property of Arcadis, all rights reserved
© Arcadis 2016
Sonolysis: The Effect of Pressure Wave Propagation
Pressure Wave
Distribution of liquid molecules
Bubble growth and collapse
Increasing bubble instability and eventual collapse
Compression Compression CompressionIncre
asin
g p
ressu
re
Relax RelaxSound energy applied to a liquid propagates as a
pressure wave, creating microbubbles.
The pressure wave results in successive
compression and rarefaction (elongation) of
the microbubbles.
The microbubbles become unstable and eventually collapse,
releasing energy in the form of heat (quasi-
adiabatic) up to 5,000 K.
Property of Arcadis, all rights reserved Adapted from Mason 200391
© Arcadis 2016
0
50
100
150
200
250
300
350
0
4
8
12
16
20
0 60 120 180 240
Flu
ori
ne
Co
nce
ntr
atio
n (
μM
)
PF
OS
Co
nce
ntr
atio
n (
µM
)
Treatment Time (minutes)
Initial PFOS = 17.5 μM
Fluorine in PFOS = 297.5 μM
Sonolysis – Proof of Concept Testing
Property of Arcadis, all rights reserved
*corr
ecte
d f
or
adsorp
tion
*corr
ecte
d f
or
adsorp
tion
AkHz PFOS
AkHz Fluorine
BkHz PFOS
BkHz Fluorine
CkHz PFOS
CkHz Fluorine
DkHz PFOS
DkHz Fluorine
92-94% Fluorine Release
(B to D kHz)
91-97% PFOS Reduction
(B to D kHz)
92
© Arcadis 2016
Sonolysis of PFASs in OZF Concentrate
93
© Arcadis 2016
0.1
1
10
100
1000
10000
0 4 8 12
[C] (m
g/L
)
Time (hr)
Cl- Cl2 ClO3- ClO4-
Electrochemical Degradation
94
• Electrochemical cells can degrade PFAS through direct electron transfer at the surface of the anode.
Applicability:
• Geochemical constituents may cause secondary concerns (i.e., chloride oxidized to perchlorate).
• Acidity around anode may facilitate PFOS sorption; needs further investigation. Confirmed effectiveness for sulfonates?
• Short chain PFAAs appear to be recalcitrant at low current density (<50 mA/cm2).
Limitations:
Benefits:
• Provides a feasible destruction mechanism for concentrated PFAS waste streams at low flow rate.
• PFAS degradation confirmed (fluorine mass balance); effective for both laboratory and real groundwater/wastewater.
1
100
10,000
1,000,000
Influent 0.15 kW-hr/L 0.26 kW-hr/L
∑P
FA
S (
pp
t)
HAL = 70
1,625,000
4,22033,040
Property of Arcadis, all rights reserved Adapted from Gomez-Ruiz et al 2017
98% reduction 99.7%
reduction
© Arcadis 2016
Arcadis Federally Funded R&D
Chemical reactivation of
spent adsorbents (SERDP)
Polymeric adsorbents (SERDP)
Assessing PFAS ecological risk
(SERDP)
IDW Treatment with E-Beam
(SERDP)
Standard and tiered approach to characterizing PFAS at FTAs
(ESTCP)
Mobile laboratory validation (ESTCP)
Sub-micron PAC ceramic
membrane filtration (ESTCP)
Passive sampler development for PFAS (SERDP)
Biotransformation and potential mineralization (PFOS, PFOA,
PFHxS) (SERDP)
Microbially-mediated
defluorination of PFAS (SERDP)
Ex-situ soil washing for PFAS
(ESTCP)
Treatment of groundwater for
PFAS using ozofractionation
(ESTCP)
In-situ soil stabilization for PFAS source areas (BAA)
Surface water
collection pondtreatment for PFAS (BAA)
Property of Arcadis, all rights reserved 95
Completed In ProgressFollow on Funding
FundedInvited for
Full Proposal
BAA
© Arcadis 2016
Summary
• Short Chains and Ethers replacing Long Chains
• Precursors form PFAAs
• Escalating regulatory and political attention globally
• Consider porfolio assessment, evaluating use and environmental sensitivity
• Volatile PFASs with long range transport contributing to low level background concentrations
• Evaluation of exposure pathways and development of site specific CSMs essential for PFAS management
• A significant mass of PFASs in source areas can bleed PFASs to form plumes for decades
• Long term liabilities and ongoing use to manage considering ultrapersistent mobile contaminants
© Arcadis 2016
PFAS Publications