Per- and Perfluoroalkyl Substances (PFAS) in Water: An...

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Per- and Perfluoroalkyl Substances (PFAS) in Water: An Overview and

Related WRF Research2018 SFPUC Annual Water Quality & Technology

WorkshopKenan Ozekin

Senior Research Manager

© 2018 The Water Research Foundation. ALL RIGHTS RESERVED.

Outline

• Background• Regulations• Occurrence• Treatment Options• WRF Research• Conclusions


PFAS in the Headlines


What are PFAS?

• Per and Polyfluoroalkyl substances (PFAS) are a class of man-made chemicals.

• The carbon-fluorine bond is the shortest and strongest chemical bond in nature

• Persistent and resistant to degradation • PFAS family=thousands of diverse compounds• PFAS are found in people, wildlife and fish all over the

world.• Some PFAS can stay in people’s bodies a long time. • Some PFAS do not break down easily in the

environment.


PFAS Family of Chemicals

Source: https://www.atsdr.cdc.gov/docs/17_278160-A_PFAS-FamilyTree-508.pdf


Uses of PFAS

• Commercial and consumer products containing PFAS were first introduced in the 1950s

• PFAS have been used for many years to make products that resist heat, stains, grease and water


Human Exposure to PFAS


History of PFAS

1950s• 1949 - 3M began producing PFOS based compunds

1960s• 1967 - FDA approved use in food packaging

2000s

• 2002 - 3M phased out PFOS production• 2008 - 3M phased out PFOA production

2010 to Present

• 2015 - All manufacturers phased out PFOA production


Potential Health Effects – Further Research Needed• Animals

• Increased liver weight (critical effect)• Spleen, thymus, and developmental• Cancer—liver, testis, pancreas

• Humans• Possible changes in growth, learning and behavior• Decreased fertility• Increased cholesterol• Immune effects• Cancer—kidney, bladder, testicular, prostate


Regulations

• No Federal Regulations• Health Advisories

EPA Provisional Health Advisory, 2009Short-term adverse health effectsPFOS: 200 ppt, PFOA: 400 ppt

EPA Health Advisory, 2016Long-term adverse health effectsPFOS: 70 ppt, PFOA: 70 ppt, PFOS + PFOA: 70 ppt

“EPA's health advisories are non-enforceable and non-regulatory and provide technical information to states agencies and other public health officials on health effects, analytical methodologies, and treatment technologies associated with drinking water contamination.”


States That Have Proposed Or Established PFAS Standards Or Guidelines

State Compound Level (ppt)

Connecticut Sum of PFOA, PFOS, PFNA, PFHxS, PFHpA 70

Maine Sum of PFOA and PFOS 70

Minnesota PFOAPFOS

3527

New Jersey PFNAPFOA

1314

North Carolina GenX 140

Vermont Sum of PFOA and PFOS 20

West Virginia Sum of PFOA and PFOS 70


PFAS Occurrence

Source: Hu XC et al., Environmental Science & Technology Letters


Treatment Options


Summary of PFAS removals for various treatment processes

Source – WRF Project 4322 Final Report


Current PFAS Water Treatment Technologies

Courtesy of – Dr. Tanju Karanfil, Clemson University


Adsorption – GAC and AIX• GAC/AIX: Breakthrough correlates with chain length.1,2,3,4,7

• GAC/AIX: Faster breakthrough for PFCAs than for PFSAs of equal carbon chain length (PFOA faster than PFOS). 1,2,3,4

• GAC/AIX: Organic matter has a negative impact upon adsorption. 1,4

• GAC/AIX: Desorption of short-chain PFCAs during co-removal (C ≤ 6 PFCA). 2,3,4

• GAC: higher surface area and larger micropores are more effective.1,5

• GAC: Dual-contactor design, careful monitoring, frequent carbon changes have proven effective at removing PFOA/PFOS.2,6

1-Appleman, et al. 2013. Journal of Hazardous Materials, 260:740–746. 2-Appleman, et al. 2014. Water Research, 51:246–255.3-Inyang and Dickenson. 2017. Chemosphere, 184:168–175.4-McCleaf et al. 2017. Water Research, 120:77-87.

5-Merino et al. 2016. Environmental Engineering Science, 33:615-649.6-Bartell, et al. 2010. Environmental Health Perspectives, 118:222–228.7-Zaggia, et al. 2016. Water Research, 91:137–146.

Source: WRF PFAS Webcast


Adsorption – Powdered Activated Carbon (PAC)• Effective towards long-chain PFAS. • Strongly dependent on organic matter and

PAC type.• GAC is typically more effective than PAC in

surface water treatment because GAC treats coagulated water that has less organic matter.



Adsorption – AIX• Polystyrene strong base > polyacrylic

strong base > weak base resins.3

• Sorption correlates with increasing hydrophobicity of the resin.4

• pHpzc>pH (aqueous), but pH<10 5

• Conventional regeneration techniques are not sufficient. 1,2

1-Deng, et al. 2010. Water Research, 44:5188–5195. 2-Carter, et al. 2010. Separation Science and Technology, 45:762–767.3-Dudley, et al. 2015. Removal of Perfluoroalkyl Substances by PAC Adsorption and Anion Exchange, WRF #4344.4-Zaggia, et al. 2016. Water Research, 91:137–146.5-Gao, et al. 2017. Journal of Hazardous Materials, 323:550–557

• AIX produces a concentrated waste stream that contains high levels of PFAS that could be difficult to treat and dispose of.



Other Adsorption Technologies• Biochar1

• Covalent Triazine-Based Framework2

• Multiwalled Carbon Nanotubes2,5

• Magnetic Mesoporous Carbon Nidride3

• Magnetic Permanently Confined Micelle Arrays4

• Molecular Imprinted Polymers6

• Electrocoagulation7

• Modified silica adsorbent8

1-Inyang and Dickenson. 2017. Chemosphere, 184:168–175 2-Wang et al. 2016. Environmental Pollution, 216:884-892.3-Yan, et al. 2014. Journal of Chemical & Engineering Data, 59:508–515.4-Wang, et al. 2014. Separation and Purification Technology, 138:7–12.5-Li, et al. 2011. Environmental Science and Technology, 45:8498.6-Yu, et al. 2008. Water Research, 42:3089.7-Lin, et al. 2015. Environmental Science and Technology, 49:10562.8-Horst et al. 2018. Groundwater Monitoring & Remediation, 38:13.


Membrane Filtration• Microfiltration and ultrafiltration provide poor removal1

• Reverse osmosis (RO) and nanofiltration (NF) provide good removal1,2,3,4,5,6,7

• RO is the most expensive to implement and operate.• RO and NF produces a concentrated waste stream that

contains high levels of PFAS that could be difficult to treat and dispose of.

1-Appleman, et al. 2013. Journal of Hazardous Materials, 260:740–746. 2-Appleman, et al. 2014. Water Research, 51:246–255.3-Tang, et al. 2006. Environmental Science & Technology, 40:7343–7349.4-Steinle-Darling, et al. 2008. Environmental Science & Technology, 42:5292–5297.5-Soriano, et al. 2017. Water Research, 112:147–156.6-Boiteux, et al. 2017. Science of the Total Environment, 583:393–400.7-Thompson, et al. 2011. Chemosphere, 82:9–17.



Chemical Oxidation• PFOA and PFOS are resistant to oxidation by ozonation and

advanced oxidation processes, such as peroxone, Fenton’s reagent, ferrate, and UV/hydrogen peroxide.1,2,3

• However, other advanced oxidation technologies have proven effective: photochemical, photocatalytic, direct photolysis, persulfate, and catalyzed H2O2 propagation.2,3,5,6

• Nonselective radicals: ●OH, O2●-, SO4

●-, CO3●-.

• In general more effective towards PFOA than PFOS and longer-chain PFAA.

1-Appleman, et al. 2014. Water Research, 51:246–255.2-Hori, et al. 2004. Environmental Science & Technology, 38:6118–6124.3-Moriwaki, et al. 2005. Environmental Science & Technology, 39:3388–3392.4-Pisarenko, et al. 2015. Environmental Science: Water Research & Technology, 1:668–678.5-Park, et al. 2016. Chemosphere, 145:376:383.6-Merino, et al. 2016. Environmental Engineering Science, 33:615–649.



Thermal/Nonthermal Destruction• Thermal-chemical reactions, incineration, sonochemistry, sub- or supercritical, microwave-

hydrothermal, E-Beam irradiation, electrochemical, and plasma electric discharge.1,2,3,4,5,6,7,8

• Thermal destruction (e.g., sonolysis) involves breaking C-C and C-F with high temperature.

• Non-thermal destruction (e.g., electrochemical, plasma) leverages both advanced oxidation and reduction processes.

• Limitations: production of toxic byproducts (for nonthermal), greenhouse gasses, and can be relatively more expensive than commercially available AOPs and sorption processes.

• Thermal destruction relies less on oxidizing and reducing radicals, thus toxic byproducts are less of an issue with these processes.

• Relevancy towards smaller volume concentrated waste streams, where reactions times can be manipulated to control energy requirements.1-Stratton, et al. 2017. Environmental Science & Technology, 51:1643–1648.2-Merino, et al. 2016. Environmental Engineering Science, 33:615–649.3-Schaefer, et al. 2015. Journal of Hazardous Materials, 295:170–175.4-Soriano, et al. 2017. Water Research, 112:147–156.5-Horst et al. 2018. Groundwater Monitoring & Remediation, 38:13.6-Urtiaga et al. 2015. Chemosphere, 129-20-26.7-Schaefer, et al. 2017. Chemical Engineering Journal, 3175:424-432.8-Vecitis, et al. 2009. Frontiers of Environmental Science & Engineering in China, 3:129-151.



Water Research Foundation PFAS Research


WRF PFAS Research


WRF Current Focus Area

• New Focus Area titled “Management, analysis, removal, fate and transport of per- and polyfluoroalkyl substances (PFAS) in water”

• Objectives• Assess effectiveness of analytical methods• Evaluate vulnerability of waters to PFAS and identify sources

and hotspots• Understand behavior, fate, and transport of PFAS in treatment

and environment• Evaluate treatment for removing PFAS and reliability of

technologies• Develop risk communication strategies


WRF 4913: Investigation of Treatment Alternatives for Short-chain PFAS

To investigate treatment alternatives for short-chain PFAS in drinking water sources

Objective

Project Team

Detlef Knappe (PI), Chris Bellona (Co-PI), Eric Rosenfeldt (Co-PI), Eric Dickenson (Co-PI), Ruth Marfil-Vega (Co-PI), and Charles Schaefer (Co-PI)


Multi-year Research Agenda

• Development of An Analytical Procedure For Total PFAS Measurement In Drinking Water, Natural Water, And Wastewater

• Interlaboratory Studies of PFAS Methods• Qualitative Structure Activity Relationships For

Predicting Removal of New and Emerging PFAS• PFAS Residual Handling And Treatment Options


New DOD Project

• Title - Evaluation and Life Cycle Comparison of Ex-Situ Treatment Technologies for Poly- and Perfluoroalkyl Substances (PFASs) in Groundwater

• Lead Organization: The Water Research Foundation (PI: Kenan Ozekin)

• Research Team: Colorado School of Mines (Chris Bellona, Chris Higgins), North Carolina State University (Detlef Knappe), University of Colorado – Boulder (Sherri Cook), CDM Smith (Charles Schaefer)

• Started October 1, 2018


DoD Project


Conclusions

• PFAS are extremely persistent and bioaccumulative• There are no Federal Regulations – only Health Advisories • Ineffective water treatment techniques:

• Ferric or alum coagulation • Granular filtration, microfiltration, ultrafiltration • Aeration/oxidation: permanganate, ultraviolet/hydrogen peroxide• Disinfection: ozone, chlorine dioxide, chlorine, and chloramines

• Anion exchange and granular activated carbon treatment preferably remove longer-chain PFAS

• Reverse osmosis and nanofiltration demonstrated significant removal for all the PFAS


Questions?Please contact

Kenan Ozekin – [email protected]

Thank you

mailto:[email protected]


Biomonitoring NHANES PFAS Data

*No serum available in 2001-2 aMeasured as isomers

*


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