I would like to present the outline of todays presentation. After the overview of PFAS I will talk about Chemistry of the PFAS compound along with sampling methods and procedures. Then you will learn about major PFAS sources in the environment. After I briefly talk about PFAS regulations amount several States and current EPA action plan that is in the process of gearing towards coming up with MCL standards I will present available treatment options in the market. Before I present todays presentation summary at the end of my talk, I will also discuss management of PFAS waste or concentrate generated during the removal process.
PFAS is Everywhere
Source: Green Science Policy Institute
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Presentation Notes
PFAS is located in many consumer products. As you can see it has being detected in Carpets, carpet cleaning products, popcorn bags, furnishers , cosmetics, raincoats and out door gear like camping tents, protective coatings used in shoes and boots. Non-stick pans, car seats and fire fighting foams. This list will continue but at least you got an idea what characteristics they bring to the table -- stain repellent in carpets, and waterproof and stain-resistant furniture. The fat and water repelling properties of these substances allowed them to be in food rappers.
PFAS related Health EffectsStudies have shown:• Increased Cancer risk:
•Colon•Kidney•Pancreatic
• Affect the immune system• Increase cholesterol
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tudies have shown that long chain PFAS like PFOA and PFOS may: cause developmental effects in infants lower a woman’s chance of getting pregnant; increase a woman’s blood pressure during pregnancy lower infant birth weights; interfere with the body’s natural hormones; increase cholesterol levels; affect the immune system; increase the risk of cancer
PFAS Levels measured in Parts per Trillion• PPT = ng/L• 10 -12
• 1 drop of water (0.05 mL) in 2 Olympic size swimming pools
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= +
PFAS StructurekJ/mol of
bonds
C-F 485
C-H 436
C-C 346
C-Cl 339
C-N 305
C-Br 285
C-S 272
PFOA
PFOSStrong C-F bonds
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Sometimes you may hear C8 Chemicals-That’s PFAS.
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Presentation Notes
PFOS – 8 Carbons 17 Fluorines 1 Sulpher 3 Oxygen and 1 Hydrogen (Negative Charge C-F bond is very strong – does not break down easily Recirculates in blood stream bound to protein PFOS and PFOA are known as "C8" PFAS, because they contain 8 carbon atoms in a chain.
Limited Analytical Methods
EPA 537.1
• SPE LC-MS/MS• 18 Compounds• For drinking water• Holding time: 14 days for
Knowledge evolves quickly! Need living sampling guidance to staff! Develop sampling and
analysis plan!8
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Note pads, gloves, raincoat or boots you wear needs to checked before you go to collect samples. PPE-Personal Protective Equipment, PCP-Personal care products, States have published “Sampling Guidelines” and recommended list of Labs.
PFAS Transport Pathways
Source: MI DEQ (2018)
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PFAS in Drinking Water Supplies
From Hu et al. 2016. Detection of Poly- and Perfluoroalkyl Substances (PFASs) in U.S. Drinking Water Linked to Industrial Sites, Military Fire Training Areas, and Wastewater Treatment Plants. ES&T Letters. 2016, 3 (10) pp. 344-350 (open access article).
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The Blue areas show PFOS (40-1,800 mg/L) in U.S. Drinking Water. Linked to Industrial Sites, Military Fire Training Areas, and WWTPs. This investigation found drinking water supplies for 6 million U.S. residents exceed US EPA's lifetime health advisory of 70 ppt for PFOS and PFOA
PFAS Sources: Landfills
• Consumer products • Industrial waste• Construction debris• Biosolids from WWTPs• Landfill leachate
• a source of PFAS for WWTP
• Landfill gas condensate• Ambient air around landfills
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PFAS Levels (PPT) from Landfill LeachatesPFAS Compounds Minimum Maximum
This is a RO plant SCS designed at New Hanover Landfill started operating in 2007. The 50,000 GPD facility has is own NPDES permit and direct discharge to surface water. Recent tests show the plant is removing almos ll PFAS compounds to non-detect levels. The table on the right shows PFAS removal rates from another 2-pass RO plant, with removal efficiencies below 2 ppt in the final effluent.
PFAS Cycle between Landfills and WWTPs
Leachate containing PFAS
Biomass containing PFAS
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The racetrack of PFAS Cycling- The PFAS relationship between WWTPs and landfills is growing more complicated. WWTPs hesitate to accept landfill leachates, and landfills refuse to receive biosolids from WWTPs because of this emerging contaminant (Figure 3). In Vermont, the leachate needs to be pre-treated before local POTWs will accept it if the PFAS exceed a certain level. Figure 3 illustrates the racetrack of PFAS cycling.
PFAS Regulations• 2016 EPA issued Health
Advisory for PFOA and PFOS limit of 70 ppt
• 2019 EPA has developed PFAS Action Plan to begin developing a Drinking Water Standard for PFAS
• Several States have established PFAS drinking water limits / advisories
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PFAS Regulations
Water
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Currently USEPA has the 70 ppt or 0.07 ppb heath advisory limit. Number of states have their own limits and interesting they got even below to USEPA limit of 70 ppt. CA, MA, NJ, VT etc are some of them. Some states currently does not have a limit and waiting to see what USEPA decides on regulations under “EPA action plan” later this year.
PFAS Treatment• GAC (Granular Activated Carbon)• IX (Ion Exchange)• RO (Reverse Osmosis)• Concentrate/Waste Management• Evaporation• Deep well injection
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PFAS Treatment - GAC Adsorption by Pores inside Carbon
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Typical GAC Process• Influent GAC vessel
• “Lead”• Second GAC vessel
• “Lag”• Monitoring
• Influent• Mid-point• Effluent
• Carbon Change Out• Lead to reactivation• Lag to lead• New to lag
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Diagram courtesy of Calgon Carbon
PFAS Treatment: GAC• May require pretreatment • Effectiveness depends on:
• pH • Temperature • contact time • NOM • Chlorine
• Better for long-chain PFAS • No brine and chemicals • GAC may be cost-
effective
Oakdale, MN
Oscoda, MI
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PFAS Treatment: Ion Exchange (IX)
Short Contact Time ~3 mins Incineration or other disposal alternative
PFAS freeTreated water
PFAS in water
Illustrations courtesy of Purolite, Inc.
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• PFAS are anions - IX can remove• Longer PFAS chains preferred over shorter chains• Resins disposed offsite (incineration)
Army Aviation Centre, Australia
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PFAS Treatment: Ion Exchange (IX)
PFAS Treatment: Reverse Osmosis (RO)
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Effective for PFAS• High pressure membrane• High energy usage• Reject water disposal• Typically used on lower flow rates• Questions about sustainability
Removes a wide range of constituents:• Hardness • Dissolved solids• PFAS• Organics• Ammonia-N
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PFAS Treatment: Reverse Osmosis (RO)
PFAS Treatment using RO
New Hanover County, NC
Presenter
Presentation Notes
This is a RO plant SCS designed at New Hanover Landfill started operating in 2017. The 50,000 GPD facility has is own NPDES permit and direct discharge to surface water. Recent tests show the plant is removing almos ll PFAS compounds to non-detect levels. The table on the right shows PFAS removal rates from another 2-pass RO plant, with removal efficiencies below 2 ppt in the final effluent.
Recent tests show the plant is removing almost PFAS compounds to non-detect levels. The table on the right shows PFAS removal rates from another 2-pass RO plant, with removal efficiencies below 2 ppt in the final effluent.
Incineration (PFAS Concentrate/Waste)
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• Thermal Method• High Energy Cost• Air Emissions• Limited Availability• Ash Disposal
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Not many facilities are available in each state but privately owned incinerator facilities are looking into PFAS contaminated sludge/concentrate to be processed at their facilities.
PFAS Treatment Efficiencies
Treatment Method PFOA PFOS Considerations
Granular Activated Carbon
48-90% 89-98%
Requires regeneration or replacement and disposal. May release PFAS into the
atmosphere
Ion Exchange 51-90% 90-99%Resins need to be
regenerated or replaced
Reverse Osmosis 90% 93-99%Waste stream contains
salts, and filtrate require disposal.
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Evaporation
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• Thermal Method• Gas requirements• Air Permit• Air Emissions/Odor Issues• Concentrate/Sludge
Disposal
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Presentation Notes
Evaporation is an option for waste steam with PFAS and significantly reduce the vole onsite. At least it may be short term solution till more established PFAS treatments are available in few year from now. Concentrate/Sludge can be recirculated back to landfill although it may become a racetrack after several years.
Deep Well Injection
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• Inject far below drinking water sources• Construction is Costly ~$4-6 M/Well• Clogging well during injection may be an issue• 3rd Party accepting 0.18-0.25/Cents Gallon
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Presentation Notes
Deep well injection of PFAS contaminated leachate or wastewater is an option in some cases. Some states do not allow and hard to get an permit. In other cases, site soli conditions and strict conditions of aquifer protection regulation will prevent this option.
SUMMARY - PFAS Treatment
• Treatment is site specific(pilot testing)• PFAS removal may be Influenced by:
• pH, water temperature, contact time, Organics and Chlorine compounds
• Polishing Step may be required• Include PFAS in leachate treatment
strategies in your future plans.
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GAC IX
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Presentation Notes
What I mean by Polishing Step is – If you are required to remove over 99% of PFAS you may need an additional back-up process after the primary PFAS removal mechanism. If your city or county owns a landfill or wastewater treatment plant that plans a infrastructure imprudent in near future allocating money for PFAS management is a good thing to consider now.
SUMMARY – PFAS Concerns
• WWTPs refuse accepting Landfill Leachates
• Landfills cancel contracts receiving Biosolids and PFAS related waste
• Land applied Biosolids is a potential source of PFAS impacts Surface water and groundwater
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You saw the race track effect on the slide I showed PFAS cycling between Landfills and WWTP. Biosolids once became a valuable resource to Farmers. Now a days it has become problematic -- especially when the PFAS tests become positive. Several framers lost the resale of milk contracts.
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PFAS infiltrated our Food Supply
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FDA tested a dairy farm near a US Air Force Base in New Mexico where firefighting foams containing PFAS have been used. local water samples tested for PFAS levels at 35 times greater than the current EPA health advisory of 70 ppt. In Maine, biosolids used at Farms were tested and they detected PFAS. However PFAS levels in the milk sold in grocery stores produced by the farms in Main were below the state. At the milk packing facility several
